JavaScript forEach() method in 8 minutes! ➿

00:00:00 introduction
00:00:18 example 1
00:03:58 example 2
00:07:37 conclusion

// forEach() = method used to iterate over the elements
// of an array and apply a specified function (callback)
// to each element

// array.forEach(callback)
// element, index, array are provided

// ------------- EXAMPLE 1 -------------

const numbers = [1, 2, 3, 4, 5];

numbers.forEach(cube);
numbers.forEach(display);

function double(element, index, array){
array[index] = element * 2;
}

function triple(element, index, array){
array[index] = element * 3;
}

function square(element, index, array){
array[index] = Math.pow(element, 2);
}

function cube(element, index, array){
array[index] = Math.pow(element, 3);
}

function display(element){
console.log(element);
}

// ------------- EXAMPLE 2 -------------

let fruits = ["apple", "orange", "banana", "coconut"];

fruits.forEach(capitalize);
fruits.forEach(display);

function upperCase(element, index, array){
array[index] = element.toUpperCase();
}

function lowercase(element, index, array){
array[index] = element.toLowerCase();
}

function capitalize(element, index, array){
array[index] = element.charAt(0).toUpperCase() + element.slice(1);
}

/*
function display(element){
console.log(element);
}
*/