Which data type is used to represent whole numbers in JavaScript?
A). number
B). integer
C). float
D). string
What will be the output of the following code: console.log(typeof 'Hello');?
A). string
B). number
C). undefined
D). boolean
What will be the output of the following code: console.log('Hello ' + 'World');?
A). Hello World
B). Hello + World
C). Hello +World
D). HelloWorld
Which symbol is used for string concatenation in JavaScript?
A). +
B). -
C). *
D). /
Which of the following is NOT a valid variable name in JavaScript?
A). _myVariable
B). 2ndVariable
C). $myVariable
D). my-Variable
Which statement correctly assigns the value true to a boolean variable isLogged in JavaScript?
A). let isLogged = 'true';
B). let isLogged = true;
C). let isLogged = 1;
D). let isLogged = 0;
What is the purpose of the NaN (Not a Number) value in JavaScript?
A). To represent a number that is not a valid JavaScript number
B). To represent a zero value
C). To represent an infinite value
D). To represent an empty string
Which keyword is used to declare a constant variable in JavaScript?
A). const
B). let
C). var
D). constant
What will be the value of x after the following code executes: let x = 10; x += 5;?
A). 15
B). 5
C). 10
D). undefined
Which method is used to convert a string to a number in JavaScript?
A). toString()
B). parseInt()
C). parseFloat()
D). toNumber()