JavaScript Fundamentals Quiz Quiz

1. Data Types

   Which of the following is not a primitive data type in JavaScript?

   1. String
   2. Number
   3. Boolean
   4. Object
   5. Undefined

2. Variable Scope

   What is the scope of a variable declared with the keyword 'let' inside a block?

   1. Global
   2. Function
   3. Block
   4. Window
   5. Local

3. Functions

   What is the purpose of a 'closure' in JavaScript?

   1. To close the browser window
   2. To bind two objects together
   3. To give access to an outer function’s scope from an inner function
   4. To prevent memory leaks
   5. To define the properties of an object

4. Arrays

   Which method adds new elements to the end of an array and returns the new length?

   1. shift()
   2. unshift()
   3. pop()
   4. push()
   5. concat()

5. Objects

   How do you access the value of a property named 'name' in an object called 'person'?

   1. person('name')
   2. person.Name
   3. person-u003Ename
   4. person[name]
   5. person.name

6. Conditional Statements

   Which statement is used to execute a block of code only if a specified condition is true?

   1. for loop
   2. while loop
   3. if statement
   4. switch statement
   5. try...catch

7. Loops

   Which type of loop iterates through the properties of an object?

   1. for loop
   2. while loop
   3. do...while loop
   4. for...in loop
   5. foreach loop

8. Events

   Which event is triggered when an HTML element loses focus?

   1. onfocus
   2. onclick
   3. onblur
   4. onchange
   5. onselect

9. String Methods

   Which string method is used to find the index of the first occurrence of a specified value in a string?

   1. search()
   2. indexAt()
   3. indexOf()
   4. findIndex()
   5. scan()

10. Operators

    What does the '===' operator do in JavaScript?

    1. Assigns a value
    2. Checks for equality after type conversion
    3. Checks for equality without type conversion
    4. Declares a variable
    5. Adds two numbers