JavaScript - Serious functions: Anonymous Functions, Scope and Closures(lexical scope, nested function, environment)

Head First JavaScript Programming
( O'Reilly Media)
Eric T. Freeman (著), Elisabeth Robson (著)

開発環境

• OS X Mavericks - Apple(OS)
• Safari, Firefox + Firebug, Google Chrome(Webプラウザ、プラグイン)
• BBEdit - Bare Bones Software, Inc. (GUI) , Emacs (CUI) (Text Editor)
• JavaScript (プログラミング言語)

Head First JavaScript Programming (Eric T. Freeman (著)、 Elisabeth Robson (著)、 O'Reilly Media )のChapter 11(Serious functions: Anonymous Functions, Scope and Closures)、EXERCISE(p.500)を解いてみる。

EXERCISE(p.500)

コード(BBEdit, Emacs)

var makePassword = function (password) {
        return function (passwordGuess) {
            return passwordGuess === password;
        };
    },
    multN = function (n) {
        return function (result) {
            return result * n;
        };
    },
    makeCounter = function () {
        var count = 0;
        return {
            increment: function () {
                count += 1;
                return count;
            }
        };
    },
    p1 = makePassword("pass1"),
    p2 = makePassword("pass2"),
    mult5 = multN(5),
    mult10 = multN(10),
    c1 = makeCounter(),
    c2 = makeCounter();

print(p1('pass1'));
print(p1('pass2'));
print(p2('pass1'));
print(p2('pass2'));

print(mult5(15));
print(mult5(20));
print(mult10(15));
print(mult10(20));

print(c1.increment())
print(c1.increment());
print(c2.increment());
print(c2.increment());