What happens when you add a number and a string in JavaScript?
A). An error is thrown
B). The number is converted to a string
C). The string is converted to a number
D). Both are converted to boolean
What is the type of the value returned by JSON.parse('null')?
A). null
B). string
C). object
D). undefined
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
Which operator is used to determine the type of a variable in JavaScript?
A). typeof
B). instanceof
C). type
D). isType
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 will typeof NaN return in JavaScript?
A). number
B). NaN
C). undefined
D). object
Given let a = '10'; let b = 20;, what is the result of a + b?
A). 30
B). 1020
C). 30
D). NaN
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
What will be the result of typeof function() {} in JavaScript?
A). function
B). object
C). undefined
D). method
In JavaScript, what will be the type of a variable x after x = 5 + true;?
A). number
B). string
C). boolean
D). undefined