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

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 scope of a variable declared using the let keyword in JavaScript?

A). Block scope

B). Function scope

C). Global scope

D). Local scope

What will be the output of the following code: console.log(parseInt('10.5'));?

A). 10

B). 5

C). '10.5'

D). NaN (Not a Number)

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

A). number

B). integer

C). float

D). string

What is the keyword used to declare variables in JavaScript?

A). let

B). variable

C). var

D). const

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

Which method is used to convert a string to a number in JavaScript?

A). toString()

B). parseInt()

C). parseFloat()

D). toNumber()

What is the value of x after the following code executes: let x = 5; x *= 2; x /= 3;?

A). 04-Oct

B). 6666666666667

C). 5

D). undefined

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 happens if you declare a variable without initializing it in JavaScript?

A). It will throw a syntax error

B). It will assign the variable a value of undefined

C). It will automatically assign a value to the variable

D). It will assign the variable a value of null