- JavaScript Basics
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- JS var
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- JS var Vs let Vs const
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- JavaScript Strings
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- JS search() Vs. indexOf()
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- JavaScript Objects
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- JavaScript Math/Number
- JS Math Object
- JS Math.abs()
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- JS Math.cbrt()
- JS Math.round()
- JS Math.ceil()
- JS Math.floor()
- JS Math.trunc
- JS toFixed()
- JS toPrecision()
- JS Math.random()
- JS Math.sign()
- JS Number.isInteger()
- JS NaN
- JS Number()
- JS parseInt()
- JS parseFloat()
- JavaScript Date and Time
- JS Date and Time
- JS Date()
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- JS getTime()
- JS getUTCFullYear()
- JS getUTCMonth()
- JS getUTCDate()
- JS getUTCDay()
- JS getUTCHours()
- JS getUTCMinutes()
- JS getUTCSeconds()
- JS getUTCMilliseconds()
- JS toDateString()
- JS toLocaleDateString()
- JS toLocaleTimeString()
- JS toLocaleString()
- JS toUTCString()
- JS getTimezoneOffset()
- JS toISOString()
- JavaScript Browser Objects
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- JavaScript Regular Expression
- JS Regular Expression
- JS RegEx .
- JS RegEx \w and \W
- JS RegEx \d and \D
- JS RegEx \s and \S
- JS RegEx \b and \B
- JS RegEx \0
- JS RegEx \n
- JS RegEx \xxx
- JS RegEx \xdd
- JS RegEx Quantifiers
- JS RegEx test()
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- JavaScript Advance
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- JS try-catch throw finally
- JS onerror Event
- JS Multimedia
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- JS getElementsByClassName()
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- JS getElementsByTagName()
- JS querySelector()
- JS querySelectorAll()
- JS document.write()
- JS console.log()
- JS instanceof
- JavaScript Programs
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Difference Between var, let, and const in JavaScript
This article is created to differentiate between var, let, and const in JavaScript. These three are the keywords, used to declare a variable in JavaScript.
var Vs let Vs const in JS
| var | let | const |
|---|---|---|
| declares function-scoped or globally-scoped variable | declares block-scoped local variable | declares block-scoped variable |
| can be updated and re-declared | can be updated but cannot be re-declared | neither can be updated nor be re-declared |
| can be declared without initializing any value | can be declared without initializing any value | can not be declared without initializing any value |
Note - Accessing a variable declared using var keyword without initialization, returns undefined.
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