What is the keyword used to declare variables in JavaScript?
A). let
B). variable
C). var
D). const
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 symbol is used for string concatenation in JavaScript?
A). +
B). -
C). *
D). /
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
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 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'
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