letVar.js

let a=10;
if(true){
    let a=20;
    console.log(a)  //20
}
console.log(a)    //10


var b=5;
if(true){
    var b=6;
    console.log(b);   //6
}
console.log(b)     //6


// In this case it will always print 10 because the scope of var is global 
// and we have set time of 1sec, so befor 1sec the value of i will be 10
for(var i=0; i<10; i++){
    setTimeout(() => {
        console.log(i);
    }, 1000)
}

// This will print 0 to 9 
for(let j=0; j<10; j++){
    setTimeout(() => {
        console.log(j);
    }, 1000);
}


// t=4444;
// u=5555;
// function fun1(){
//     setTimeout(() => {
//         console.log("This will give the output");
//         console.log(t);
//         console.log(u);
//     }, 3000);
//     var t;
//     let u;
// }
// fun1();