es6 foreach against array and string code example

Example 1: javascript .foreach

let colors = ['red', 'blue', 'green'];
// idx and sourceArr optional; sourceArr == colors
colors.forEach(function(color, idx, sourceArr) {
	console.log(color, idx, sourceArr)
});
// Output:
// red 0 ['red', 'blue', 'green']
// blue 1 ['red', 'blue', 'green']
// green 2 ['red', 'blue', 'green']

Example 2: perform a function on each element of array javascript

var new_array = old_array.map(function(e) { 
  e.data = e.data.split(','); 
  return e;
});