What is the keyword used to declare variables in JavaScript?

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 symbol is used for string concatenation in JavaScript?

A). +

B). -

C). *

D). /

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

A). 04-Oct

B). 6666666666667

C). 5

D). undefined

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

A). toString()

B). parseInt()

C). parseFloat()

D). toNumber()

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

A). _myVariable

B). 2ndVariable

C). $myVariable

D). my-Variable

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