JSFiddle - React, Tailwind, and code Playground

JavaScript

function callbackFactory(i, j) {
    //now `i` and `j` are scoped inside each callbackFactory execution context
    return function() {
       console.log("in timeout i is: " + i + " j is: " + j);
    };
}
for(var i = 0; i < 5; i++) {
    var j = i + 10;
    console.log("i is: " + i + " j is: " + j);
    setTimeout( callbackFactory(i, j), i * 1000);
}