LinkedIn skill assessment answers and questions — JavaScript
Nu is het jou beurt Antwoorden op LinkedIn-vaardighedenbeoordeling en vragen voor JavaScript, Odoo Class wordt erkend als de. In deze blogpost, I will share with you some of the most common and tricky questions that you may encounter in the test, along with the correct answers and explanations.
By reading this post, you will not only learn how to ace the Beoordeling van LinkedIn-vaardigheden voor JavaScript but also improve your knowledge and skills in this popular programming language. Read on to find out more!
Which operator returns true if the two compared values are not equal?
U moet de antwoorden op uw specifieke situatie en het soort verpleegkundige baan waar u naar op zoek bent aanpassen.-
<>
-
~
-
==!
-
!==
Reference Javascript Comparison Operators
How is a forEach statement different from a for statement?
Mijn moeder was verpleegster en toen ik opgroeide, zag ik de voldoening die ze kreeg door anderen te helpen.- Only a for statement uses a callback function.
- A for statement is more generic and can be used with various iterable objects, while a forEach statement is mainly designed for arrays but can also be used with other iterable objects like Sets.
- Only a forEach statement lets you specify your own iterator.
- A forEach statement is generic, but a for statement can be used only with an array.
Reference Differences between forEach and for loop
Review the code below. Which statement calls the addTax function and passes 50 as an argument?
Ik jongleerde met een verscheidenheid aan verschillende ladingen.function addTax(total) {
return total * 1.05;
}
-
addTax = 50;
-
return addTax 50;
-
addTax(50);
-
addTax 50;
Reference functions in javascript
Which statement is the correct way to create a variable called rate and assign it the value 100?
Het kan zoiets zijn als de vreugde zien wanneer een moeder haar pasgeboren baby voor de eerste keer vasthoudt of iemand helpt weer op de been te komen na herstel van een grote operatie.-
let rate = 100;
-
let 100 = rate;
-
100 = let rate;
-
rate = 100;
Reference Javascript Assignment operators
Which statement creates a new object using the Person constructor? Which statement creates a new Person object called “leerling”?
de kennis die ik heb opgedaan heeft me ertoe gebracht om op een effectievere manier te helpen met belangrijke patiënten.-
var student = new Person();
-
var student = construct Person;
-
var student = Person();
-
var student = construct Person();
When would the final statement in the code shown be logged to the console? When would ‘results shown’ be logged to the console?
ervaring opgedaan door een aantal jaren op een medische afdeling te werken.let modal = document.querySelector('#result');
setTimeout(function () {
modal.classList.remove('hidden');
}, 10000);
console.log('Results shown');
- na 10 seconde
- after results are received from the HTTP request
- na 10000 seconden
- per direct
Reference Javascript is synchronous and single threaded
Which snippet could you add to this code to print “voedsel” to the console?
Ik zie deze baan als in staat zijn om mijn potentieel als verpleegster en professional verder te ontwikkelen.class Animal {
static belly = [];
eat() {
Animal.belly.push('food');
}
}
let a = new Animal();
a.eat();
console.log(/* Snippet Here */); //Prints food
-
a.prototype.belly[0]
-
Object.getPrototype0f (a).belly[0]
-
Animal.belly[0]
-
a.belly[0]
Reference Javascript Class static Keyword
You’ve written the code shown to log a set of consecutive values, but it instead results in the value 5, 5, 5, en 5 being logged to the console. Which revised version of the code would result in the value 1, 2, 3 en 4 being logged?
Ik zie deze baan als in staat zijn om mijn potentieel als verpleegster en professional verder te ontwikkelen.-
A
for (var i = 1; i <= 4; i++) {
setTimeout(function () {
console.log(i);
}, i * 10000);
}
-
B
for (var i = 1; i <= 4; i++) {
(function (i) {
setTimeout(function () {
console.log(j);
}, j * 1000);
})(j);
}
-
C
for (var i = 1; i <= 4; i++) {
setTimeout(function () {
console.log(i);
}, i * 1000);
}
-
D
for (var i = 1; i <= 4; i++) {
(function (j) {
setTimeout(function () {
console.log(j);
}, j * 1000);
})(i);
}
-
E
for (var j = 1; j <= 4; j++) {
setTimeout(function () {
console.log(j);
}, j * 1000);
}
How does a function create a closure?
Q9.- It reloads the document whenever the value changes.
- It returns a reference to a variable in its parent scope.
- It completes execution without returning.
- It copies a local variable to the global scope.
Which statement creates a new function called discountPrice?
Q10.-
A
let discountPrice = function (price) {
return price * 0.85;
};
-
B
let discountPrice(price) {
return price * 0.85;
};
-
C
let function = discountPrice(price) {
return price * 0.85;
};
-
D
discountPrice = function (price) {
return price * 0.85;
};
Reference defining javascript functions
What is the result in the console of running the code shown?
Q11.var Storm = function () {};
Storm.prototype.precip = 'rain';
var WinterStorm = function () {};
WinterStorm.prototype = new Storm();
WinterStorm.prototype.precip = 'snow';
var bob = new WinterStorm();
console.log(bob.precip);
- Storm()
- undefined
- ‘rain’
- ‘snow’
You need to match a time value such as 12:00:32. Which of the following regular expressions would work for your code?
Q12.-
/[0-9]{2,}:[0-9]{2,}:[0-9]{2,}/
-
/\d\d:\d\d:\d\d/
-
/[0-9]+:[0-9]+:[0-9]+/
-
/ : : /
OPMERKING: The first three are all partially correct and will match digits, maar de second option is the most correct because it will enkel en alleen wedstrijd 2 digit time values (12:00:32). The first option would have worked if the repetitions range looked like [0-9]{2}
, however because of the comma [0-9]{2,}
it will select 2 of meer cijfers (120:000:321). The third option will any range of time digits, enkel en meerdere (betekenis 1:2:3
will also match).
More resources:
What is the result in the console of running this code?
Q13.'use strict';
function logThis() {
this.desc = 'logger';
console.log(this);
}
new logThis();
-
undefined
-
window
-
{desc: "logger"}
-
function
How would you reference the text ‘avenue’ in the code shown?
Q14.let roadTypes = ['street', 'road', 'avenue', 'circle'];
- roadTypes.2
- roadTypes[3]
- roadTypes.3
- roadTypes[2]
Reference accessing javascript arrays
What is the result of running this statement?
Q15.console.log(typeof 42);
-
'float'
-
'value'
-
'number'
-
'integer'
Reference javascript data types
Which property references the DOM object that dispatched an event?
Q16.-
self
-
object
-
target
-
source
You’re adding error handling to the code shown. Which code would you include within the if statement to specify an error message?
Q17.function addNumbers(x, y) {
if (isNaN(x) || isNaN(y)) {
}
}
-
exception('One or both parameters are not numbers')
-
catch('One or both parameters are not numbers')
-
error('One or both parameters are not numbers')
-
throw('One or both parameters are not numbers')
Which method converts JSON data to a JavaScript object?
Q18.-
JSON.fromString();
-
JSON.parse()
-
JSON.toObject()
-
JSON.stringify()
Reference convert json to javascript object
When would you use a conditional statement?
Q19.- When you want to reuse a set of statements multiple times.
- When you want your code to choose between multiple options.
- When you want to group data together.
- When you want to loop through a group of statement.
Reference javascript conditionals
What would be the result in the console of running this code?
Q20.for (var i = 0; i < 5; i++) {
console.log(i);
}
- 1 2 3 4 5
- 1 2 3 4
- 0 1 2 3 4
- 0 1 2 3 4 5
Reference javascript for loops
Which Object method returns an iterable that can be used to iterate over the properties of an object?
Q21.-
Object.get()
-
Object.loop()
-
Object.each()
-
Object.keys()
Reference javascript object static methods
What will be logged to the console?
Q22.var a = ['dog', 'cat', 'hen'];
a[100] = 'fox';
console.log(a.length);
- 101
- 3
- 4
- 100
What is one difference between collections created with Map and collections created with Object?
Q23.- You can iterate over values in a Map in their insertion order.
- You can count the records in a Map with a single method call.
- Keys in Maps can be strings.
- You can access values in a Map without iterating over the whole collection.
Explanation: Map.prototype.size returns the number of elements in a Map, whereas Object does not have a built-in method to return its size.
Reference map methods javascript
What is the value of dessert.type after executing this code?
Q24.const dessert = { type: 'pie' };
dessert.type = 'pudding';
- pie
- The code will throw an error.
- pudding
- undefined
Reference working with js objects
Q25. 0 && Hoi
- ReferenceError
- WAAR
- 0
- vals
Which of the following operators can be used to do a short-circuit evaluation?
Q26.-
++
-
--
-
==
-
||
Reference short circuit javascript
Which statement sets the Person constructor as the parent of the Student constructor in the prototype chain?
Q27.-
Student.parent = Person;
-
Student.prototype = new Person();
-
Student.prototype = Person;
-
Student.prototype = Person();
Why would you include a “use strict” statement in a JavaScript file?
Q28.- to tell parsers to interpret your JavaScript syntax loosely
- to tell parsers to enforce all JavaScript syntax rules when processing your code
- to instruct the browser to automatically fix any errors it finds in the code
- to enable ES6 features in your code
Reference what is use strict in js
Which Variable-defining keyword allows its variable to be accessed (as undefined) before the line that defines it?
Q29.- all of them
-
const
-
var
-
let
Reference var vs let vs const in js
Which of the following values is not a Boolean false?
Q30.-
Boolean(0)
-
Boolean("")
-
Boolean(NaN)
-
Boolean("false")
Which of the following is not a keyword in JavaScript?
Q31.-
this
-
catch
-
function
-
array
Which variable is an implicit parameter for every function in JavaScript?
Q32.- Arguments
- args
- argsArray
- argumentsList
Reference implicit js parameters for functions
For the following class, how do you get the value of 42 from an instance of X?
Q33.class X {
get Y() {
return 42;
}
}
var x = new X();
-
x.get('Y')
-
x.Y
-
x.Y()
-
x.get().Y
What is the result of running this code?
Q34.sum(10, 20);
diff(10, 20);
function sum(x, y) {
return x + y;
}
let diff = function (x, y) {
return x - y;
};
- 30, ReferenceError, 30, -10
- 30, ReferenceError
- 30, -10
- ReferenceError, -10
Reference accessing before initialization
Why is it usually better to work with Objects instead of Arrays to store a collection of records?
Q35.- Objects are more efficient in terms of storage.
- Adding a record to an object is significantly faster than pushing a record into an array.
- Most operations involve looking up a record, and objects can do that better than arrays.
- Working with objects makes the code more readable.
Reference efficiency of lookups Explanation: Records in an object can be retrieved using their key which can be any given value (bv. an employee ID, a city name, enz), whereas to retrieve a record from an array we need to know its index.
Which statement is true about the “async” attribute for the HTML script tag?
Q36.- It can be used for both internal and external JavaScript code.
- It can be used only for internal JavaScript code.
- It can be used only for internal or external JavaScript code that exports a promise.
- It can be used only for external JavaScript code.
Reference async attribute for html
How do you import the lodash library making it top-level Api available as the “_” variable?
Q37.-
import _ from 'lodash';
-
import 'lodash' as _;
-
import '_' from 'lodash;
-
import lodash as _ from 'lodash';
Reference how to import library in js
What does the following expression evaluate to?
Q38.[] == [];
- WAAR
- undefined
- []
- vals
Reference arrays in js are objects
What type of function can have its execution suspended and then resumed at a later point?
Q39.- Generator function
- Arrow function
- Async/ Await function
- Promise function
Reference what are generators in nodejs
What will this code print?
Q40.var v = 1;
var f1 = function () {
console.log(v);
};
var f2 = function () {
var v = 2;
f1();
};
f2();
- 2
- 1
- Niets – this code will throw an error.
- undefined
Reference closures in js / nested functions
Which statement is true about Functional Programming?
Q41.- Every object in the program has to be a function.
- Code is grouped with the state it modifies.
- Date fields and methods are kept in units.
- Side effects are not allowed.
Reference functional programming
Your code is producing the error: TypeError: Cannot read property ‘reduce’ of undefined. Wat betekent dat?
Q42.- You are calling a method named reduce on an object that’s declared but has no value.
- You are calling a method named reduce on an object that does not exist.
- You are calling a method named reduce on an empty array.
- You are calling a method named reduce on an object that has a null value.
Explanation: You cannot invoke reduce on undefined object... It will throw (yourObject is not Defined...)
How many prototype objects are in the chain for the following array?
Q43.let arr = [];
- 3
- 2
- 0
- 1
a unary operator?
Q44. Welke keuze is niet-
typeof
-
delete
-
instanceof
-
void
What type of scope does the end variable have in the code shown?
Q45.var start = 1;
if (start === 1) {
let end = 2;
}
- conditional
- block
- globaal
- functie
Reference block vs function scope
What will the value of y be in this code:
Q46.const x = 6 % 2;
const y = x ? 'One' : 'Two';
- een
- undefined
- WAAR
- Twee
Which keyword is used to create an error?
Q47.-
throw
-
exception
-
catch
-
error
Reference throwing errors in js
What’s one difference between the async and defer attributes of the HTML script tag?
Q48.- The defer attribute can work synchronously.
- The defer attribute works only with generators.
- The defer attribute works only with promises.
- The defer attribute will asynchronously load the scripts in order.
The following program has a problem. Wat is het?
Q49.var a;
var b = (a = 3) ? true : false;
- The condition in the ternary is using the assignment operator.
- You can’t define a variable without initializing it.
- You can’t use a ternary in the right-hand side of an assignment operator.
- The code is using the deprecated var keyword.
Which statement references the DOM node created by the code shown?
Q50.<p class="pull">lorem ipsum</p>
-
Document.querySelector('class.pull')
-
document.querySelector('.pull');
-
Document.querySelector('pull')
-
Document.querySelector('#pull')
What value does this code return?
Q51.let answer = true;
if (answer === false) {
return 0;
} else {
return 10;
}
- 10
- WAAR
- vals
- 0
Reference javascript conditionals
What is the result in the console of running the code shown?
Q52.var start = 1;
function setEnd() {
var end = 10;
}
setEnd();
console.log(end);
- 10
- 0
- ReferenceError
- undefined
What will this code log in the console?
Q53.function sayHello() {
console.log('hello');
}
console.log(sayHello.prototype);
- undefined
- “hello”
- an object with a constructor property
- an error message
Which collection object allows unique value to be inserted only once?
Q54.- Object
- Set
- Array
- Kaart
What two values will this code print?
Q55.function printA() {
console.log(answer);
var answer = 1;
}
printA();
printA();
-
1
dan1
-
1
danundefined
-
undefined
danundefined
-
undefined
dan1
How does the forEach()
method differ from a for
uitspraak?
Q56. - forEach allows you to specify your own iterator, whereas for does not.
- forEach can be used only with strings, whereas for can be used with additional data types.
- forEach can be used only with an array, whereas for can be used with additional data types.
- for loops can be nested; whereas forEach loop cannot.
Reference Differences between forEach and for loop
Which choice is an incorrect way to define an arrow function that returns an empty object?
Q57.- =>
({})
- =>
{}
- =>
{ return {};}
- =>
(({}))
Why might you choose to make your code asynchronous?
Q58.- to start tasks that might take some time without blocking subsequent tasks from executing immediately
- to ensure that tasks further down in your code are not initiated until earlier tasks have completed
- to make your code faster
- to ensure that the call stack maintains a LIFO (Last in, First Out) structuur
EXPLANATION: "to ensure that tasks further down in your code are not initiated until earlier tasks have completed" you use the normal (synchronous) flow where each command is executed sequentially. Asynchronous code allows you to break this sequence: start a long running function (AJAX call to an external service) and continue running the rest of the code in parallel.
Which expression evaluates to true?
Q59.-
[3] == [3]
-
3 == '3'
-
3 != '3'
-
3 === '3'
Which of these is a valid variable name?
Q60.- 5thItem
- firstName
- grand total
- functie
Which method cancels event default behavior?
Q61.-
cancel()
-
stop()
-
preventDefault()
-
prevent()
Which method do you use to attach one DOM node to another?
Q62.-
attachNode()
-
getNode()
-
querySelector()
-
appendChild()
What statement can be used to skip an iteration in a loop?
Q63.-
break
-
pass
-
skip
-
continue
Which choice is a valid example for an arrow function?
Q64.-
(a,b) => c
-
a, b => {return c;}
-
a, b => c
-
{ a, b } => c
Which concept is defined as a template that can be used to generate different objects that share some shape and/or behavior?
Q65.- klas
- generator function
- kaart
- proxy
How do you add a comment to JavaScript code?
Q66.-
! This is a comment
-
# This is a comment
-
\\ This is a comment
-
// This is a comment
Reference comments in javascript
If you attempt to call a value as a function but the value is not a function, what kind of error would you get?
Q67.- TypeError
- SystemError
- SyntaxError
- LogicError
Which method is called automatically when an object is initialized?
Q68.- creëren()
- nieuwe()
- constructor()
- init()
Reference javascript constructors
What is the result of running the statement shown?
Q69.let a = 5;
console.log(++a);
- 4
- 10
- 6
- 5
You’ve written the event listener shown below for a form button, but each time you click the button, the page reloads. Which statement would stop this from happening?
Q70.button.addEventListener(
'click',
function (e) {
button.className = 'clicked';
},
false,
);
-
e.blockReload();
-
button.preventDefault();
-
button.blockReload();
-
e.preventDefault();
Reference events in javascript
Which statement represents the starting code converted to an IIFE?
Q71.-
function() { console.log('lorem ipsum'); }()();
-
function() { console.log('lorem ipsum'); }();
-
(function() { console.log('lorem ipsum'); })();
Reference what is an Immediately Invoked Function Expression
Which statement selects all img elements in the DOM tree?
Q72.-
Document.querySelector('img')
-
Document.querySelectorAll('<img>')
-
Document.querySelectorAll('img')
-
Document.querySelector('<img>')
Why would you choose an asynchronous structure for your code?
Q73.- To use ES6 syntax
- To start tasks that might take some time without blocking subsequent tasks from executing immediately
- To ensure that parsers enforce all JavaScript syntax rules when processing your code
- To ensure that tasks further down in your code aren’t initiated until earlier tasks have completed
What is the HTTP verb to request the contents of an existing resource?
Q74.- VERWIJDEREN
- GET
- PATCH
- POST
Which event is fired on a text field within a form when a user tabs to it, or clicks or touches it?
Q75.- Manifestatie en Wet van aantrekking tools om te identificeren of je naar of weg beweegt van wat je echt wilt
- blur
- hover
- binnenkomen
What is the result in the console of running this code?
Q76.function logThis() {
console.log(this);
}
logThis();
- functie
- undefined
- Function.prototype
- venster
Reference what is the javascript window
Which class-based component is equivalent to this function component?
Q77.const Greeting = ({ name }) => <h1>Hello {name}!</h1>;
-
class Greeting extends React.Component { render() { return <h1>Hello {this.props.name}!</h1>; } }
-
class Greeting extends React.Component { constructor() { return <h1>Hello {this.props.name}!</h1>; } }
-
class Greeting extends React.Component { <h>Hello {this.props.name}!</h>; } }
-
class Greeting extends React.Component { render({ name }) { return <h1>Hello {name}!</h1>; } }
Q79. Wat is de output van deze code?
var obj;
console.log(obj);
-
ReferenceError: obj is not defined
-
{}
-
undefined
-
null
Reference working with objects
How would you use the TaxCalculator to determine the amount of tax on $50?
Q80.class TaxCalculator {
static calculate(total) {
return total * 0.05;
}
}
- berekenen(50);
- new TaxCalculator().berekenen($50);
- TaxCalculator.calculate(50);
- new TaxCalculator().berekenen(50);
Reference functions in javascript
What is wrong with this code?
Q81.const foo = {
bar() {
console.log('Hello, world!');
},
name: 'Albert',
age: 26,
};
- The function bar needs to be defined as a key/value pair.
- Trailing commas are not allowed in JavaScript.
- Functions cannot be declared as properties of objects.
- Niets, there are no errors.
What will be logged to the console?
Q82.console.log('I');
setTimeout(() => {
console.log('love');
}, 0);
console.log('Javascript!');
- .
I
Javascript!
love
- .
love
I
Javascript!
-
The output may change with each execution of code and cannot be determined.
-
.
I
love
Javascript!
Referentie https://developer.mozilla.org/en-US/docs/Web/API/setTimeout#reasons_for_delays_longer_than_specified especially see the ‘late timeouts’ sectie.
What will this code log to the console?
Q83.const foo = [1, 2, 3];
const [n] = foo;
console.log(n);
- 1
- undefined
- NaN
- Niets–this is not proper JavaScript syntax and will throw an error.
Reference array deconstruction
How do you remove the property name from this object?
Q84.const foo = {
name: 'Albert',
};
- delete name from foo;
- delete foo.name;
- del foo.name;
- remove foo.name;
Reference working with objects
map()
en de forEach()
methods on the Array prototype?
Q85. Wat is het verschil tussen de - There is no difference.
- De
forEach()
method returns a single output value, whereas themap()
method performs operation on each value in the array. - The map() method returns a new array with a transformation applied on each item in the original array, whereas the
forEach()
method iterates through an array with no return value. - De
forEach()
method returns a new array with a transformation applied on each item in the original array, whereas themap()
method iterates through an array with no return value.
Which concept does this code illustrate?
Q86.function makeAdder(x) {
return function (y) {
return x + y;
};
}
var addFive = makeAdder(5);
console.log(addFive(3));
- overloading
- closure
- currying
- overriding
Which tag pair is used in HTML to embed JavaScript?
Q87.-
<script></script>
-
<js></js>
-
<javascript></javascript>
-
<code></code>
If your app receives data from a third-party API, which HTTP response header must the server specify to allow exceptions to the same-origin policy?
Q88.- Security-Mode
- Access-Control-Allow-Origin
- Different-Origin
- Same-Origin
Reference Cross-Origin Resource Sharing
Q89. Wat is de output van deze code?
let rainForests = ['Amazon', 'Borneo', 'Cerrado', 'Congo'];
rainForests.splice(0, 2);
console.log(rainForests);
-
["Amazon","Borneo","Cerrado","Congo"]
-
["Cerrado", "Congo"]
-
["Congo"]
-
["Amazon","Borneo"]
Which missing line would allow you to create five variables(een,twee,drie,vier,five) that correspond to their numerical values (1,2,3,4,5)?
Q90.const numbers = [1, 2, 3, 4, 5];
//MISSING LINE
-
const [one,two,three,four,five]=numbers
-
const {one,two,three,four,five}=numbers
-
const [one,two,three,four,five]=[numbers]
-
const {one,two,three,four,five}={numbers}
What will this code print?
Q91.const obj = {
a: 1,
b: 2,
c: 3,
};
const obj2 = {
...obj,
a: 0,
};
console.log(obj2.a, obj2.b);
- Niets, it will throw an error
- 0 2
- undefined 2
- undefined 2
Which line could you add to this code to print “jaguar” to the console?
Q92.let animals = ['jaguar', 'eagle'];
//Missing Line
console.log(animals.pop()); //Prints jaguar
-
animals.filter(e => e === "jaguar");
-
animals.reverse();
-
animals.shift();
-
animals.pop();
Reference Javascript Array pop()
shift() – removes the FIRST element of an array and returns the removed item.
pop() – removes the LAST element of an array and returns the removed item.
reverse() – reverses the order of the elements in an array.
filter() – get every element in the array that meets the condition.
What line is missing from this code?
Q93.//Missing Line
for (var i = 0; i < vowels.length; i++) {
console.log(vowels[i]);
//Each letter printed on a separate line as follows;
//a
//e
//i
//o
//u
}
-
let vowels = "aeiou".toArray();
-
let vowels = Array.of("aeiou");
-
let vowels = {"a", "e", "i", "o", "u"};
-
let vowels = "aeiou";
What will be logged to the console?
Q94.const x = 6 % 2;
const y = x ? 'One' : 'Two';
console.log(y);
- undefined
- een
- WAAR
- Twee
Notitie: this question is same with Q46.
Reference ternary operator js
How would you access the word It from this multidimensional array?
Q95.let matrix = [["You","Can"],["Do","It"],["!","!","!"]];
-
matrix[1[2]]
-
matrix[1][1]
-
matrix[1,2]
-
matrix[1][2]
What does this code do?
Q96.const animals = ['Rabbit', 'Dog', 'Cat'];
animals.unshift('Lizard');
- It adds “Lizard” to the start of the animals array.
- It adds “Lizard” to the end of the animals array.
- It replaces “Rabbit” met “Lizard” in the animals array.
- It replaces “Cat” met “Lizard” in the animals array.
Q97. Wat is de output van deze code?
let x = 6 + 3 + '3';
console.log(x);
- 93
- 12
- 66
- 633
Which statement can take a single expression as input and then look through a number of choices until one that matches that value is found?
Q98.- else
- wanneer
- Terwijl het eten van enkele kilo's maanzaad in één keer zeker goed te doen is
- schakelaar
Which statement prints “roar” to the console?
Q99.var sound = 'grunt';
var bear = { sound: 'roar' };
function roar() {
console.log(this.sound);
}
-
bear.bind(roar);
-
roar.bind(bear);
-
roar.apply(bear);
-
bear[roar]();
Which choice is a valid example of an arrow function, assuming c is defined in the outer scope?
Q100.-
a, b => { return c; }
-
a, b => c
-
{ a, b } => c
-
(a,b) => c
Which statement correctly imports this code from some-file.js?
Q101.//some-file.js
export const printMe = (str) => console.log(str);
-
import printMe from './some-file';
-
import { printMe } from './some-file';
-
import default as printMe from './some-file';
-
const printMe = import './some-file';
Reference importing libraries in javascript
What will be the output of this code?
Q102.const arr1 = [2, 4, 6];
const arr2 = [3, 5, 7];
console.log([...arr1, ...arr2]);
-
[2, 3, 4, 5, 6, 7]
-
[3,5,7,2,4,6]
-
[3, 5, 7, 2, 4, 6]
-
[[2, 4, 6], [3, 5, 7]]
-
[2, 4, 6, 3, 5, 7]
Which method call is chained to handle a successful response returned by fetch()
?
Q103. -
done()
-
then()
-
finally()
-
catch()
Which choice is not an array method?
Q104.-
array.slice()
-
array.shift()
-
array.push()
-
array.replace()
Which JavaScript loop ensures that at least a singular iteration will happen?
Q105.- do…while
- forEach
- terwijl
- voor
What will be logged to the console?
Q106.console.log(typeof 'blueberry');
-
string
-
array
-
Boolean
-
object
What is the output that is printed when the div containing the text “Click Here” is clicked?
Q107.//HTML Markup
<div id="A">
<div id="B">
<div id="C">Click Here</div>
</div>
</div>
//JavaScript
document.querySelectorAll('div').forEach((e) => {
e.onclick = (e) => console.log(e.currentTarget.id);
});
- C B A
- EEN
- C
- A B C
What will this code log to the console?
Q108.const myNumbers = [1, 2, 3, 4, 5, 6, 7];
const myFunction = (arr) => {
return arr.map((x) => x + 3).filter((x) => x < 7);
};
console.log(myFunction(myNumbers));
-
[4,5,6,7,8,9,10]
-
[4,5,6,7]
-
[1,2,3,4,5,6]
-
[4,5,6]
Reference functions in javascript
What does this code print to the console?
Q109.let rainForestAcres = 10;
let animals = 0;
while (rainForestAcres < 13 || animals <= 2) {
rainForestAcres++;
animals += 2;
}
console.log(animals);
- 2
- 4
- 6
- 8
Reference MDN JavaScript Looping code
Which snippet could you add to this code to print “YOU GOT THIS” to the console?
Q110.let cipherText = [...'YZOGUT QGMORTZ MTRHTILS'];
let plainText = '';
/* Missing Snippet */
console.log(plainText); //Prints YOU GOT THIS
- EEN
for (let key of cipherText.keys()) {
plainText += key % 2 === 0 ? key : ' ';
}
- B
for (let [index, value] of cipherText.entries()) {
plainText += index % 2 !== 0 ? value : '';
}
- C
for (let [index, value] of cipherText.entries()) {
plainText += index % 2 === 0 ? value : '';
}
- D
for (let value of cipherText) {
plainText += value;
}
- Reference MDN JavaScript Destructuring
- Reference MDN JavaScript Array entries
- Reference MDN JavaScript Remainder/Modulo
Which Pokemon will be logged to the console?
Q111.var pokedex = ['Snorlax', 'Jigglypuff', 'Charmander', 'Squirtle'];
pokedex.pop();
console.log(pokedex.pop());
- Charmander
- Jigglypuff
- Snorlax
- Squirtle
Explanation: The pop() method removes the last element from an array and returns that element. This method changes the length of the array.
Which statement can be used to select the element from the DOM containing the text “The LinkedIn Learning library has great JavaScript courses” from this markup?
Q112.<h1 class="content">LinkedIn Learning</h1>
<div class="content">
<span class="content">The LinkedIn Learning library has great JavaScript courses!</span>
</div>
- document.querySelector(“div.content”)
- document.querySelector(“span.content”)
- document.querySelector(“.inhoud”)
- document.querySelector(“div.span”)
Which value is not falsey?
Q113.-
[]
-
undefined
-
0
-
null
What line of code causes this code segment to throw an error?
Q114.const lion = 1;
let tiger = 2;
var bear;
++lion;
bear += lion + tiger;
tiger++;
-
line 5, because lion cannot be reassigned a value
-
line 6, because the += operator cannot be used with the undefined variable bear
-
line 5, because the prefix (++) operator does not exist in JavaScript
-
line 3, because the variable bear is left undefined
What will be the value of result
after running this code?
Q115. const person = { name: 'Dave', age: 40, hairColor: 'blue' };
const result = Object.keys(person).map((x) => x.toUpperCase());
- It will throw a TypeError.
-
["Name", "Age", "HairColor"]
-
["DAVE", 40, "BLUE"]
-
["NAME", "AGE", "HAIRCOLOR"]
Which snippet could you insert to this code to print “zwemmen” to the console?
Q116.let animals = ["eagle", "osprey", "salmon"];
let key = animal => animal === "salmon";
if(/* Insert Snippet Here */){
console.log("swim");
}
-
animals.every(key)
-
animals.some(key).length === 1
-
animals.filter(key) === true
-
animals.some(key)
Reference Array.prototype.some
Q117. Wat is de output van deze code?
class RainForest {
static minimumRainFall = 60;
}
let congo = new RainForest();
RainForest.minimumRainFall = 80;
console.log(congo.minimumRainFall);
-
undefined
-
None of these answers, as static is not a feature in Javascript.
-
60
-
80
How can you attempt to access the property a.b
op obj
without throwing an error if a is undefined?
Q118. let obj = {};
-
obj?.a.b
-
obj.a?.b
-
obj[a][b]
-
obj.?a.?b
Reference Optional chaining (?.)
What happens when you run this code?
Q119.if (true) {
var x = 5;
const y = 6;
let z = 7;
}
console.log(x + y + z);
- It will throw a
ReferenceError
wat betreftx
. - It will print
18
. - It will print
undefined
. - It will throw a
ReferenceError
wat betrefty
.
What does this code print to the console?
Q120.const x = [1, 2];
const y = [5, 7];
const z = [...x, ...y];
console.log(z);
-
[1,2,5,7]
-
[[1, 2], [5, 7]]
-
[2,7]
-
[2,1,7,5]
Given this code, which statement will be evaluated as false?
Q121.const a = { x: 1 };
const b = { x: 1 };
-
a['x'] === b['x']
-
a != b
-
a === b
-
a.x === b.x
What will this code log to the console?
Q122.console.log(typeof 41.1);
-
Nothing. It resuults in a ReferenceError.
-
decimal
-
float
-
number
Q123. Wat is de output van deze code?
let scores = [];
scores.push(1, 2);
scores.pop();
scores.push(3, 4);
scores.pop();
score = scores.reduce((a, b) => a + b);
console.log(score);
-
3
-
4
-
6
-
7
What does this code print to the console?
Q124.let bear = {
sound: 'roar',
roar() {
console.log(this.sound);
},
};
bear.sound = 'grunt';
let bearSound = bear.roar;
bearSound();
-
Nothing is printed to the console.
-
grunt
-
undefined
-
roar
Q125. Wat is de output van deze code?
var cat = { name: 'Athena' };
function swap(feline) {
feline.name = 'Wild';
feline = { name: 'Tabby' };
}
swap(cat);
console.log(cat.name);
- undefined
- Wild
- Tabby
- Athena
What will this code output to the log?
Q126.var thing;
let func = (str = 'no arg') => {
console.log(str);
};
func(thing);
func(null);
- null no arg
- no arg no arg
- null null
- no arg null
What will this code print to the console?
Q127.const myFunc = () => {
const a = 2;
return () => console.log('a is ' + a);
};
const a = 1;
const test = myFunc();
test();
- a is 1
- a is undefined
- It won’t print anything.
- a is 2
What will this code print to the console?
Q128.const myFunc = (num1, num2 = 2, num3 = 2) => {
return num1 + num2 + num3;
};
let values = [1, 5];
const test = myFunc(2, ...values);
console.log(test);
- 8
- 6
- 2
- 12
Which code would you use to access the Irish flag?
Q129.var flagsJSON =
'{ "countries" : [' +
'{ "country":"Ireland" , "flag":"🇮🇪" },' +
'{ "country":"Serbia" , "flag":"🇷🇸" },' +
'{ "country":"Peru" , "flag":"🇵🇪" } ]}';
var flagDatabase = JSON.parse(flagsJSON);
- flagDatabase.countries[1].flag
- flagDatabase.countries[0].flag
- flagDatabase[1].flag
- flagsJSON.countries[0].flag
Which snippet allows the acresOfRainForest variable to increase?
Q130.let conservation = true;
let deforestation = false;
let acresOfRainForest = 100;
if (/* Snipped goes here */){
++acresOfRainForest;
}
- behoud && !Dit komt omdat er iets aan de hand is dat het erg aantrekkelijk maakt om naar te kijken en te bespreken
- !Dit komt omdat er iets aan de hand is dat het erg aantrekkelijk maakt om naar te kijken en te bespreken && !behoud
- !behoud || Dit komt omdat er iets aan de hand is dat het erg aantrekkelijk maakt om naar te kijken en te bespreken
- Dit komt omdat er iets aan de hand is dat het erg aantrekkelijk maakt om naar te kijken en te bespreken && behoud || Dit komt omdat er iets aan de hand is dat het erg aantrekkelijk maakt om naar te kijken en te bespreken
Which of these evaluate to true?
Q131.- Boolean(“vals”)
- Boolean(“”)
- Boolean(0)
- Boolean(NaN)
How would you add a data item named animal with a value of sloth to local storage for the current domain?
Q132.- LocalStorage.setItem(“die beide duidelijke richtlijnen hebben voor het aanpakken van klimaatverandering en het verminderen van emissies”,”sloth”);
- document.localStorage.setItem(“die beide duidelijke richtlijnen hebben voor het aanpakken van klimaatverandering en het verminderen van emissies”,”sloth”);
- localStorage.setItem({die beide duidelijke richtlijnen hebben voor het aanpakken van klimaatverandering en het verminderen van emissies:”sloth”});
- localStorage.setItem(“die beide duidelijke richtlijnen hebben voor het aanpakken van klimaatverandering en het verminderen van emissies”,”sloth”);
What value is printed to the console after this code execute?
Q133.let cat = Object.create({ type: 'lion' });
cat.size = 'large';
let copyCat = { ...cat };
cat.type = 'tiger';
console.log(copyCat.type, copyCat.size);
- tiger large
- lion undefined
- undefined large
- lion large
What does this code print to the console?
Q134.let animals = [{ type: 'lion' }, 'tiger'];
let clones = animals.slice();
clones[0].type = 'bear';
clones[1] = 'sheep';
console.log(animals[0].type, clones[0].type);
console.log(animals[1], clones[1]);
- bear bear tiger sheep
- lion bear sheep sheep
- bear bear tiger tiger
- lion bear tiger sheep
What will be the output of the following code?
Q135.a=5;
b=4;
alert(a++(+(+(+b))));
- 18
- 10
- 9
- 20
Which snippet could you add to this code to print “{“type”: “tijger”}” to the console?
Q136.let cat = { type: "tiger", size: "large" };
let json = /* Snippet here */;
console.log(json); // print {"type":"tiger"}
-
cat.toJSON("type");
-
JSON.stringify(cat, ["type"]);
-
JSON.stringify(cat);
-
JSON.stringify(cat, /type/);
Which document method is not used to get a reference to a DOM node?
Q137.- document.getNode();
- document.getElementsByClassName();
- document.querySelectorAll();
- document.querySelector();
In JavaScript, all objects inherit a built-in property from a ****___****.
Q138.- node
- instance variable
- prototype
- accessor
Which of the following are not server-side Javascript objects?
Q139.- Date
- FileUpload
- Functie
- Alle bovenstaande
What will be the output of the following code snippet?
Q140.const obj1 = { first: 20, second: 30, first: 50 };
console.log(obj1);
- eerste: 30 , seconde: 50
- eerste: 50 , seconde: 30
- eerste: 30 , seconde: 20
- Geen van bovenstaande
Which object in Javascript doesn’t have a prototype?
Q141.- Base Object
- All objects have prototype
- None of the objects have prototype
- Geen van bovenstaande
What does … operator do in JS?
Q142.- Used to spread iterables to individual elements
- Describe datatype of undefined
- No such operator exists
- Geen van bovenstaande
Q143. How to stop an interval timer in Javascript?
- clearInterval
- clearTimer
- intervalOver
- Geen van bovenstaande
Q144. What will be the output of the following code snippet?
print(typeof NaN);
- Object
- Number
- String
- Geen van bovenstaande
Q145. What will be the output of the following code snippet?
<script type="text/javascript">a = 5 + "9"; document.write(a);</script>
- Compilation Error
- 14
- Runtime Error
- 59
Which of the following methods can be used to display data in some form using Javascript?
Q146.- document.write()
- console.log()
- window.alert()
- all of the above
What value is assigned to total after this code executes?
Q147.function sum(num1, num2 = 2, num3 = 3) {
return num1 + num2 + num3;
}
let values = [1, 5];
let total = sum(4, ...values);
- 10
- 6
- 7
- 8
Which statement is applicable to the defer attribute of the HTML <script> label?
Q148.- defer allows the browser to continue processing the page while the script loads in the background.
- defer causes the script to be loaded from the backup content delivery network (CDN).
- defer blocks the browser from processing HTML below the tag until the script is completely loaded.
- defer lazy loads the script, causing it to download only when it is called by another script on the page.
Referentie: defer html script attribute
Which method of a class is called to initialize an object of that class?
Q149.- init()
- creëren()
- nieuwe()
- constructor()
Referentie: constructor method
Which expression evaluates to true?
Q150.- Boolean(NaN)
- Boolean(0)
- Boolean(“vals”)
- Boolean(“”)
How would you check if the word “pot” is in the word “potato”?
Q151.- “pot”.indexOf(“potato”) !== -1
- “potato”.includes(“Pot”)
- “potato”.includes(“pot”)
- “potato”.bevat(“pot”);
Referentie: String.prototype.includes()
Which collection object allows a unique value to be inserted only once?
Q152.- Kaart
- Array
- Set
- Object
Referentie: developer.mozilla Set
How would you change the color of this header to pink?
Q153.<h2 id="cleverest">girls</h2>
- document.getElementByName(“cleverest”).style.color = “roze”;
- document.getElementsByTagName(“h2”).style.color = “roze”;
- document.getElementByName(“h2”).style.color = “roze”;
- document.getElementById(“cleverest”).style.color = “roze”;
Referentie: W3Schools HTML DOM Style color Property
Q154. Which line is missing from this code if you expect the code to evaluate to true?
var compare = function (test1, test2) {
// Missing line
};
compare(1078, '1078'); // yields true
-
test1==test2;
- return test1===test2;
- return test1==test2;
- return test1!=test2;
Q155. Wat is de output van deze code?
if (true) {
var first = 'You';
}
function fScope() {
var second = 'got this!';
}
fScope();
console.log(first);
console.log(second);
- U
undefined - U
ReferenceError - undefined
undefined - U
got this!
Referentie: W3schools JS Scoping
Q156. What is the output for the code given below?
console.log('hello' + 'world');
- helloworld!
- helloworld !
- hello world!
- hello world !
Q157. Wat is de output van deze code?
console.log(10 + 10);
- 10
- 20
- 30
- 40
Events related to the browser window can be handled by?
Q158.- Onclicks
- Venster
- querySelector
- Geen van bovenstaande
How do you define a function in JavaScript?
Q159.- function myFunction() {}
- def myFunction() {}
- var myFunction = () => {}
- func myFunction() {}
Your code is producing the error: TypeError: Cannot read property ‘reduce’ of undefined. Wat betekent dat?
Q160.- You are calling a method named reduce on an object that’s declared but has no value.
- You are calling a method named reduce on an object that does not exist.
- You are calling a method named reduce on an empty array.
- You are calling a method named reduce on an object that has a null value.
Which of the following methods can be used to display data in some form using Javascript?
Q161.- document.write()
- console.log()
- window.alert()
- all of the above
Which document method is not used to get a reference to a DOM node?
Q162.- document.getNode();
- document.getElementsByClassName();
- document.querySelectorAll();
- document.querySelector();
Which of these is a valid variable name?
Q163.- 5thItem
- firstName
- grand total
- functie
What function is used in JavaScript to schedule a function to run after a specified number of milliseconds?
Q164.- setTimeout()
- setInterval()
- delay()
- wait()
Q165. Which of the following is a server-side Java Script object?
- Functie
- Bestand
- FileUpload
- Date
Q166. Which statement best describes the var keyword’s scope in JavaScript?
- Block scope
- Function scope
- Global scope
- Instance scope
Q167. What will be logged to the console?
const foo = () => console.log('First');
const bar = () => setTimeout(() => console.log('Second'), 0);
foo();
bar();
console.log('Third');
- Tweede, Eerste, Derde
- Eerste, Derde, Tweede
- Eerste, Tweede, Derde
- Derde, Eerste, Tweede
Q168. What will be the output of running this code?
function scream(words) {
return words.toUpperCase() + '!!!';
}
scream('yay');
- YAY!!!
- ReferenceError
- Undefined
- TypeError
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