forEach

//ES5 example:

var colours ['red', 'blue', 'green'];

for (var i=0; i <colours.length; i++ {
    console.log(colours[i]); 
}

//ES6 solution: 

colours.forEach(function(color) {
    console(color); 
}); 

//More example:

var numbers = [1,2,3,4,5];
var sum = 0; 

//When we call the forEach we pass an anonymous function (Iterator function) 
//This function gets called one time for every element in the array 
numbers.forEach(function(number) {
    sum += number; 
}); 
console.log(sum); 

//We can also take the inner function out: 

function adder(number) {
    sum+=number
}

numbers.forEach(adder);