Answers for "difference between let var const in js"

26

var vs let vs const

var: 
	- hoisted (always declared at top of scope, global if none)
    - function scope
let:
    - block scope
    - not redeclarable
const: 
    - block scope
    - not reassignable
    - not redeclarable
    
Note: Although it may seem like these hold only semantic meaning, using the
appropriate keywords helps the JS engines' compiler to decide on what to optimize.
Posted by: Guest on May-11-2021
7

difference between let, var and const in java script

//let is used to declare the variable or initialize a variable..
//let variable can be updated in future.
//Its block scope and we cannot redeclare it.

let a; // Initializing the variable.
let b = 4; // Initializing and declaring variable.
let b = 5; //Error:- cannot redeclare a value but we can update the value.

//var is just like let but var is used to declare a variable value at top of
//the program, its hoisted.

var a; // Initializing the variable.
var b = 4; // Initializing and declaring variable.
var b = 5; //b will be redeclared and we can update its value.

//const variable should be declared and intialized at same time.
//const variable cannot be updated in future.
//we cannot even redeclare the variable in future.

const a = 10; //Initilizing and declaring a variable at a time.
const b; //Error:- const should be declared and intialized.
const a = 11 // Error:- cannot redeclare the variable again.
Posted by: Guest on September-15-2021
5

what is the difference between let and const in javascript

The difference is that with const you can only only assign a value to a variable
once, but with let it allows you to reassign after it has been assigned.
Posted by: Guest on June-29-2020

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