What is the result of the expression 5 + '5' in JavaScript?

Which primitive value represents absence of value or no value assigned?

A). undefined

B). null

C). 0

D). 'undefined'

Which of the following statements is true about JavaScript's null value?

A). It represents an empty string

B). It represents a non-existent value

C). It represents a boolean value

D). It represents a number

What is a primitive value in JavaScript?

A). A complex data structure

B). A basic data type

C). A function

D). An array

What is the data type of the value undefined in JavaScript?

A). String

B). Object

C). Undefined

D). Number

What is the data type of the value NaN in JavaScript?

A). Number

B). String

C). Object

D). Undefined

Which of the following is a primitive data type in JavaScript?

A). Array

B). Object

C). Function

D). String

Which of the following is a valid way to represent the value null in JavaScript?

A). undefined

B). NULL

C). null

D). None of the above

What happens when you try to access a variable that has not been declared in JavaScript?

A). SyntaxError is thrown

B). ReferenceError is thrown

C). TypeError is thrown

D). Undefined

What happens when you add two numbers using the + operator in JavaScript?

A). The numbers are concatenated

B). The numbers are multiplied

C). The numbers are added

D). An error occurs

Which of the following statements about primitive values in JavaScript is true?

A). They are mutable

B). They are passed by reference

C). They are stored on the heap

D). They are immutable