What will typeof NaN return in JavaScript?
A). number
B). NaN
C). undefined
D). object
How can you check if a variable is an array in JavaScript?
A). typeof variable === 'array'
B). Array.isArray(variable)
C). variable instanceof array
D). variable.constructor === array
Which type conversion happens automatically in the expression 3 + '5'?
A). Number to String
B). String to Number
C). Boolean to String
D). Number to Boolean
What does the parseInt function do in JavaScript?
A). Converts a number to a string
B). Converts a string to an integer
C). Converts a boolean to a number
D). Converts an array to a number
What does it mean that JavaScript is dynamically typed?
A). Variables do not have types
B). Variables can change type
C). Variables must be declared with a type
D). Variables cannot change type
What is the initial type of a variable declared with let a;?
A). null
B). number
C). undefined
D). object
Which of the following values is considered falsy in JavaScript?
A). 1
B). 0
C). 0
D). {}
Given the code: let y = 10; y = true;, what is the type of y after execution?
A). number
B). boolean
C). string
D). object
What is the type of the value returned by parseFloat('3.14abc')?
A). number
B). string
C). NaN
D). undefined
What is the type of the value returned by JSON.parse('null')?
A). null
B). string
C). object
D). undefined