Which symbol is used for string concatenation in JavaScript?
A). +
B). -
C). *
D). /
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 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
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 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 method is used to convert a string to a number in JavaScript?
A). toString()
B). parseInt()
C). parseFloat()
D). toNumber()
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 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 is the keyword used to declare variables in JavaScript?
A). let
B). variable
C). var
D). const