var VS let VS const

 program to state difference between Var, Let and Const:

// let

let a = 10

console.log(a)

{

    let a= 100

console.log(a)

}

console.log(a)

//var :- rarely used

var b = 20

console.log(b)

{

   var b= 100

console.log(b)

}

console.log(b)

//const

const pi = 3.14

console.log(pi)

{

    // let pi =0  const can't be declared again but value can be changed

   const pi= 3.142

console.log(pi)

}

console.log(pi)

Output: