Best way to wait for .forEach() to complete

If there is no asynchronous code inside the forEach, forEach is not asynchronous, for example in this code:

array.forEach(function(item){ 
    //iterate on something 
});
alert("Foreach DONE !");

you will see the alert after forEach finished.

Otherwise (You have something asynchronous inside), you can wrap the forEach loop in a Promise:

var bar = new Promise((resolve, reject) => {
    foo.forEach((value, index, array) => {
        console.log(value);
        if (index === array.length -1) resolve();
    });
});

bar.then(() => {
    console.log('All done!');
});

Credit: @rolando-benjamin-vaz-ferreira