Show List
Quiz - JavaScript - 4
Select the right answer for below questions:
What is the difference between let and var in JavaScript?
let is function scoped, while var is block scoped
var and let are interchangeable and have no difference
var is function scoped, while let is block scoped
let cannot be used in JavaScript
var is function scoped, while let is block scoped
How do you declare an array in JavaScript?
Using the “array” keyword
Using square brackets []
Using curly braces {}
Using parenthesis ()
Using square brackets []
What is the difference between an object and an array in JavaScript?
An object is a collection of values, while an array is a collection of key-value pairs
There is no difference
An array is a collection of values, while an object is a collection of key-value pairs
Arrays and objects cannot be used in JavaScript
An array is a collection of values, while an object is a collection of key-value pairs
What is hoisting in JavaScript?
Hoisting is the behavior of moving function and variable declarations to the top of their respective scopes
Hoisting is the behavior of moving function and variable declarations to the bottom of their respective scopes
Hoisting cannot be used in JavaScript
Hoisting is the behavior of deleting function and variable declarations
Hoisting is the behavior of moving function and variable declarations to the top of their respective scopes
How do you declare a constant in JavaScript?
Using the “let” keyword
Using the “var” keyword
Using the “const” keyword
Constants cannot be declared in JavaScript
Using the “const” keyword
What is the difference between forEach() and map() in JavaScript?
forEach() modifies the original array, while map() returns a new array
map() modifies the original array, while forEach() returns a new array
There is no difference
forEach() and map() cannot be used in JavaScript
forEach() modifies the original array, while map() returns a new array
What is the difference between synchronous and asynchronous code in JavaScript?
Synchronous code runs in the order it is written, while asynchronous code runs out of order
Asynchronous code runs in the order it is written, while synchronous code runs out of order
There is no difference
Synchronous and asynchronous code cannot be used in JavaScript
Synchronous code runs in the order it is written, while asynchronous code runs out of order
How do you declare a variable in JavaScript?
Using the “let” keyword
Using the “const” keyword
Using the “var” keyword
Variables cannot be declared in JavaScript
Using the “var” keyword
What is a Promise in JavaScript?
A Promise is a function that runs synchronously
A Promise is a data structure
A Promise is an object representing the eventual completion or failure of an asynchronous operation
Promises cannot be used in JavaScript
A Promise is an object representing the eventual completion or failure of an asynchronous operation
What is the difference between null and undefined in JavaScript?
Null is a value that represents no value or no object, while undefined means a variable has been declared but has not yet been assigned a value
Undefined is a value that represents no value or no object, while null means a variable has been declared but has not yet been assigned a value
There is no difference
Null and undefined cannot be used in JavaScript
Null is a value that represents no value or no object, while undefined means a variable has been declared but has not yet been assigned a value
Submit
Retry
{"qz1-901739":"var is function scoped, while let is block scoped","qz1-901740":"Using square brackets []","qz1-901741":"An array is a collection of values, while an object is a collection of key-value pairs","qz1-901742":"Hoisting is the behavior of moving function and variable declarations to the top of their respective scopes","qz1-901743":"Using the “const” keyword","qz1-901744":"forEach() modifies the original array, while map() returns a new array","qz1-901745":"Synchronous code runs in the order it is written, while asynchronous code runs out of order","qz1-901746":"Using the “var” keyword","qz1-901747":"A Promise is an object representing the eventual completion or failure of an asynchronous operation","qz1-901748":"Null is a value that represents no value or no object, while undefined means a variable has been declared but has not yet been assigned a value"}
Leave a Comment