for each in node js 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: foreach javascript

let names = ['josh', 'joe', 'ben', 'dylan'];
// index and sourceArr are optional, sourceArr == ['josh', 'joe', 'ben', 'dylan']
names.forEach((name, index, sourceArr) => {
	console.log(color, idx, sourceArr)
});

// josh 0 ['josh', 'joe', 'ben', 'dylan']
// joe 1 ['josh', 'joe', 'ben', 'dylan']
// ben 2 ['josh', 'joe', 'ben', 'dylan']
// dylan 3 ['josh', 'joe', 'ben', 'dylan']

Example 3: for each

const array1 = ['a', 'b', 'c'];

array1.forEach(element => console.log(element));

// expected output: "a"
// expected output: "b"
// expected output: "c"

Example 4: what foreach method returns in javascript

function double(arr) {
  return arr.forEach(num => num*2);
}

console.log(double([1,2,3,4])) //undefined