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 typeof null return in JavaScript?
A). null
B). undefined
C). object
D). 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 will be the result of typeof function() {} in JavaScript?
A). function
B). object
C). undefined
D). method
What is the initial type of a variable declared with let a;?
A). null
B). number
C). undefined
D). object
What is the type of the value returned by JSON.parse('null')?
A). null
B). string
C). object
D). undefined
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 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
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 will be the result of the following code: let z = '123'; z = Number(z); console.log(typeof z);?
A). string
B). number
C). undefined
D). boolean