Which keyword is used to declare a constant variable in JavaScript?
A). const
B). let
C). var
D). constant
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(typeof 'Hello');?
A). string
B). number
C). undefined
D). boolean
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;
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 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
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)
What will be the output of the following code: console.log('Hello ' + 'World');?
A). Hello World
B). Hello + World
C). Hello +World
D). HelloWorld