how to create dynamic function in javascript with for loop and its index inside function

Question

    var data = ["s","a"]
    var asyncFunctionss = [];

    for (var i in data) {
        asyncFunctionss.push(function (callback) {
            console.log(i);
        });
    }
    for (var g in asyncFunctionss) {
        asyncFunctionss[g]();
    }

I try to run this program it give the following output.

Expected Output

0

1

Actual Output

1

1

How to achieve the Expected output ?

Answer 1

You need an IIFE. The reason is that as soon as a function element in asyncFunctionss is called the variable i is already 1. You could use a IIFE to remember the value of variable i:

var data = ["s","a"]
var asyncFunctionss = [];

for (var i in data) {
  (function(i){
    asyncFunctionss.push(function (callback) {
        console.log(i);
    });
  })(i);
}
for (var g in asyncFunctionss) {
    asyncFunctionss[g]();
}