JavaScript Basics: Core Concepts

Question 1

Which keyword declares a block-scoped variable in modern JavaScript?

A var B let C int D define

💡 Explanation

'let' is correct because it declares a block-scoped variable introduced in ES6.

Question 2

What method outputs a message to the browser console?

A print() B echo() C console.log() D log.console()

💡 Explanation

console.log() is correct because it is the standard way to print to the JavaScript console.

Question 3

Which symbol is used for strict equality comparison?

A = B == C === D !=

💡 Explanation

'===' is correct because it compares both value and type without coercion.

Question 4

What data structure uses square brackets [] in JavaScript?

A Object B Array C Function D String

💡 Explanation

Array is correct because square brackets denote an ordered list of values.

Question 5

Which function converts a JSON string into a JavaScript object?

A JSON.stringify() B JSON.parse() C JSON.object() D parse.JSON()

💡 Explanation

JSON.parse() is correct because it parses a JSON string and returns the resulting object.