JavaScript - Types, Equality, Conversion and All That Jazz: Serious types(undefined)

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 7(Types, Equality, Conversion and All That Jazz: Serious types)、WHO AM I?(p.267)を解いてみる。

WHO AM I?(p.267)

すべてundefined。

確認。

コード(BBEdit, Emacs)

var f = function () {},
    a,
    b = [1, 2],
    c = {'a':1};

print(f());
print(a);
b[100] = 10;
print(b[2]);
print(b['b']);
delete c['a'];
print(c['a']);
c.a;
print(c.a);