JavaScript Fundamentals

Variables, Types, Operators, Scope, Hoisting, Storage

Questions

1
beginner

What is the difference between "Pass by Value" and "Pass by Reference"?

pass-by-valuepass-by-referenceprimitives
2
beginner

What is the difference between null and undefined?

nullundefinedtypes
3
beginner

What is the difference between == and === in JavaScript?

equalityoperatorstype-coercion
4
beginner

Is JavaScript a dynamically typed or statically typed language?

dynamic-typingtypestypescript
5
beginnerMulti-select

What are the differences between let, var and const? (Select all that apply)

varletconst
6
beginner

What is Hoisting in JavaScript?

hoistingvariablesfunctions
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What is the Temporal Dead Zone (TDZ)?

temporal-dead-zoneletconst
8
beginner

What is setTimeout in JavaScript?

setTimeoutasynctimers
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What is the difference between setTimeout and setInterval?

setTimeoutsetIntervaltimers
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What is IIFE (Immediately Invoked Function Expression)?

iifefunctionsscope
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What is destructuring in JavaScript?

destructuringes6syntax
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What is the main difference between Local Storage and Session Storage?

localStoragesessionStoragestorage
13
beginner

What will console.log(typeof null) output?

typeofnulltypes
14
beginner

What is NaN in JavaScript?

NaNnumberstypes
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What is the output of console.log(0.1 + 0.2 === 0.3)?

floating-pointnumbersprecision
16
beginner

What is the output of console.log("5" + 3)?

type-coercionoperatorsstrings
17
beginner

What are template literals in JavaScript?

template-literalsstringses6
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What is the purpose of "use strict" in JavaScript?

strict-modebest-practicesdebugging
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What is the difference between function declarations and function expressions?

functionshoistingdeclarations
20
beginnerMulti-select

What are falsy values in JavaScript? (Select all that apply)

falsytruthyboolean