forEach.js

// 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


/*
let numbers = [1, 2, 3, 4, 5];

numbers.forEach(double);
numbers.forEach(triple);
numbers.forEach(square); 

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);
}

*/

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);
}