JavaScript Basics Quiz
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Question 1/15
What method is used to add new elements to the end of an array?
Select your answer
Question 2/15
What will the following expression return: Boolean(0);
Boolean(0);
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Question 3/15
Which method can be used to convert a JSON string into a JavaScript object?
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Question 4/15
What will the value of "x" be after the code is run?
let x = 5;
x = x * 2;
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Question 5/15
Which company developed JavaScript?
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Question 6/15
Which of the following data types exists in JavaScript?
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Question 7/15
How do you round 7.25 to the nearest integer in JavaScript?
Math.round(7.25);
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Question 8/15
Which operator is used to assign a value to a variable?
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Question 9/15
What will the following code output?
var fruits = ['Apple', 'Banana', 'Mango'];
console.log(fruits[1]);
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Question 10/15
Which one of these is an Arrow Function syntax?
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Question 11/15
How do you find the number with the highest value of x and y?
Math.max(x, y);
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Question 12/15
What is the correct way to declare a variable in JavaScript?
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Question 13/15
What is a typical use case for the "isNaN()" function?
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Question 14/15
What is the output when you execute the following code?
console.log(typeof 42);
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Question 15/15
How do you write an "if" statement in JavaScript to execute some code if "i" is equal to 5?
if (i === 5) {
// code to execute
}
Select your answer
Your Results
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Your Answers
Question 1/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What method is used to add new elements to the end of an array?
Available answers
The
push()
method adds one or more elements to the end of an array.
Question 2/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What will the following expression return: Boolean(0);
Boolean(0);
Available answers
The expression
Boolean(0)
returns false
because 0
is considered a "falsy" value in JavaScript.
Question 3/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
Which method can be used to convert a JSON string into a JavaScript object?
Available answers
The
JSON.parse()
method is used to convert a JSON string into a JavaScript object.
Question 4/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What will the value of "x" be after the code is run?
let x = 5;
x = x * 2;
Available answers
The operation
x = x * 2
assigns the result of 5 * 2
to x
, which is 10
.
Question 5/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
Which company developed JavaScript?
Available answers
JavaScript was developed by Netscape as a client-side scripting language.
Question 6/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
Which of the following data types exists in JavaScript?
Available answers
JavaScript supports data types such as
String, Number, Boolean, Object
, but not specific types like Character
or Tuple
.
Question 7/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
How do you round 7.25 to the nearest integer in JavaScript?
Math.round(7.25);
Available answers
To round a number in JavaScript, use
Math.round()
.
Question 8/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
Which operator is used to assign a value to a variable?
Available answers
The assignment operator in JavaScript is
=
, used to assign values to variables.
Question 9/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What will the following code output?
var fruits = ['Apple', 'Banana', 'Mango'];
console.log(fruits[1]);
Available answers
Arrays in JavaScript are zero-indexed, so
fruits[1]
contains 'Banana'
.
Question 10/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
Which one of these is an Arrow Function syntax?
Available answers
An Arrow Function does not use the
function
keyword and looks like (x, y) => x + y
.
Question 11/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
How do you find the number with the highest value of x and y?
Math.max(x, y);
Available answers
The function
Math.max()
is used to find the highest value among its parameters.
Question 12/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What is the correct way to declare a variable in JavaScript?
Available answers
In JavaScript, you declare a variable using the
var
, let
, or const
keyword, such as var myVariable;
.
Question 13/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What is a typical use case for the "isNaN()" function?
Available answers
The
isNaN()
function checks if a value is NaN (Not-a-Number).
Question 14/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
What is the output when you execute the following code?
console.log(typeof 42);
Available answers
The
typeof
operator returns 'number'
for numerical literals like 42
.
Question 15/15
😊 Your
answer was correct
🙁 Your
answer was incorrect
How do you write an "if" statement in JavaScript to execute some code if "i" is equal to 5?
if (i === 5) {
// code to execute
}
Available answers
The syntax for an "if" statement in JavaScript to check for equality is:
if (i === 5) { /* code */ }
.