let vs const vs var javascript code example
Example 1: let vs const
`const` is a signal that the identifier won't be reassigned.
`let` is a signal that the variable may be reassigned, such as a counter in a
loop, or a value swap in an algorithm.
It also signals that the variable will be used only in the block it's defined
in, which is not always the entire containing function.
Example 2: var let const javascript
Const vs Let vs Var
const pi = 3.14
pi = 1
cannot do this becuase with const you cannot change the value
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Let --> is block level
for(let i = 0; i < 3; i++) {
console.log(i) --> it will console here
}
console.log(i) ---> Not here
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Var is for variables available to the entire function
for(var j = 0; j < 3; j++) {
console.log(j) --> it will console here
}
console.log(j) ---> it will console here
Example 3: const let var scope
var num = 1;
const num = 2;
let num = 3;
Example 4: var or const in javascript
const myConst='A const does not change.';
var myVar='A var does change.';
var myVar=2;
Example 5: difference between var let and const in javascript with example
var a;
a=10;
let a;
a=10;
let a =20;
if(true){
let b =30;
}
console.log(b);
const
const a;
const a =20;
if(true){
const b =30;
}
console.log(b);
console.log(a);