Get Programming with JavaScript

Get Programming with JavaScript - Listing 8.07

Listing 8.07 - Iterating over an array with forEach

var items;
var showInfo;

items = [
    "The Pyramids",
    "The Grand Canyon",
    "Bondi Beach"
];

showInfo = function (itemToShow) {
    console.log(itemToShow);
};

items.forEach(showInfo);

Further Adventures

Listing 8.07 - Iterating over an array with forEach - Task 1

Add a few extra items to the array, some using push and some using square brackets.

var items;
var showInfo;

items = [
    "The Pyramids",
    "The Grand Canyon",
    "Bondi Beach"
];

showInfo = function (itemToShow) {
    console.log(itemToShow);
};

items.push("The Taj Mahal");
items.push("Popocatépetl");

items[items.length] = "The Tower of London";
items[items.length] = "Old Faithful";

items.forEach(showInfo);

Listing 8.07 - Iterating over an array with forEach - Task 2

Update the showInfo function to also display the number of letters in each item.

var items;
var showInfo;

items = [
    "The Pyramids",
    "The Grand Canyon",
    "Bondi Beach"
];

showInfo = function (itemToShow) {
    console.log(itemToShow + " has " + itemToShow.length + " letters");
};

items.forEach(showInfo);

Listing 8.07 - Iterating over an array with forEach - Task 3

Write a new function that finds the total number of letters of the elements in the items array.

var items;
var getNumLetters;   // declare a variable

items = [
    "The Pyramids",
    "The Grand Canyon",
    "Bondi Beach"
];

// define a function and
// assign it to the variable
getNumLetters = function (itemsArray) {
    var runningTotal = 0;

    itemsArray.forEach(function (item) {
        runningTotal += item.length;
    });

    return runningTotal;
};

// test the function
console.log("Total letters = " + getNumLetters(items));