use of 4 parameters inside foreach in js code example

Example 1: foreach loop javascript

const numList = [1, 2, 3];

numList.forEach((number) => {
  console.log(number);
});

Example 2: what is foreach method in javascript

var arr = [1, 2, 3, 4, 5, 6];

//var sum = 0;
arr.forEach(function (value, index, array){  // Built in method
    //sum += value;
    console.log(value, index, array);
})

//console.log(sum);  // We can print sum of all Array element (if those are numbers)

// function forEach(arr, cb){  // How forEach() method works
//     for (var i = 0; i<arr.length; i++){
//         cb(arr[i], i, arr);
//     }
// }
// var sum = 0;
// forEach(arr, function (value, index, arr){
//     console.log(value, index, arr);
//     sum += value;
// })
// console.log(sum);