What will be the output of the following code: console.log('Hello ' + 'World');?

What will be the value of x after the following code executes: let x = '5' + 5;?

A). '55'

B). 10

C). 5

D). '10'

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 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;

Which symbol is used for string concatenation in JavaScript?

A). +

B). -

C). *

D). /

What is the purpose of using the === operator in JavaScript?

A). Strict equality comparison

B). Loose equality comparison

C). Assignment operator

D). Addition operator

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

What is the keyword used to declare variables in JavaScript?

A). let

B). variable

C). var

D). const

Which of the following is NOT a valid variable name in JavaScript?

A). _myVariable

B). 2ndVariable

C). $myVariable

D). my-Variable

Which data type is used to represent whole numbers in JavaScript?

A). number

B). integer

C). float

D). string

Which variable declaration is appropriate if you want a variable to hold a constant value throughout the program execution?

A). let

B). var

C). const

D). constant