JavaScript Fundamentals

Quiz Questions

1. Which keyword is used to declare a constant in JavaScript?
   • var
   • let
   • const
   • constant
2. What is the result of typeof null in JavaScript?
   • 'null'
   • 'undefined'
   • 'object'
   • 'boolean'
3. How do you write 'Hello World' in an alert box?
   • alertBox('Hello World')
   • alert('Hello World')
   • msg('Hello World')
   • popup('Hello World')
4. Which method adds an element to the end of an array?
   • push()
   • pop()
   • shift()
   • unshift()
5. What does === operator check?
   • Value only
   • Type only
   • Both value and type
   • Neither
6. How do you create a function in JavaScript?
   • function myFunction()
   • create myFunction()
   • def myFunction()
   • func myFunction()
7. What is the correct way to write a JavaScript array?
   • var colors = 'red', 'green', 'blue'
   • var colors = (1:'red', 2:'green', 3:'blue')
   • var colors = ['red', 'green', 'blue']
   • var colors = 1 = ('red'), 2 = ('green'), 3 = ('blue')
8. Which event occurs when the user clicks on an HTML element?
   • onmouseclick
   • onclick
   • onchange
   • onmouseover
9. What is NaN in JavaScript?
   • A string
   • A number
   • Not a Number
   • Null and None
10. How do you find the length of an array named 'arr'?
    • arr.length
    • arr.size()
    • arr.len
    • length(arr)