forEach() method calls a function for each element in an array.

Function Proto-type 1:

Array.forEach( function(currentValue, index, arr) {
	...
} );


Function Proto-type 2: simplified version

Array.forEach( function(currentValue) {
	...
} );




Example 1) Compute the sum:

let sum = 0;
const numbers = [ 65, 44, 12, 4 ];

numbers.forEach( function(v) {
	sum += v;
});


Example 2) Compute the sum:

let sum = 0;
const numbers = [ 65, 44, 12, 4 ];

numbers.forEach( myFunction);

function myFunction(v)
{
	sum += v;
}


Example 3) Multiple each element:

let sum = 0;
const numbers = [ 65, 44, 12, 4 ];

numbers.forEach( function(v, idx, arr) {
	arr[idx] = v * 10;
});