转载地址：http://dmitrysoshnikov.com/ecmascript/chapter-2-variable-object/
Introduction
Always in programs we declare functions and variables which then successfully use building our systems. But how and where the interpreter finds our data (functions, variable)? What occurs, when we reference to needed objects?
Many ECMAScript programmers know that variables are closely related with the execution context:
var a = 10; // variable of the global context
(function () {
var b = 20; // local variable of the function context
})();alert(a); // 10
alert(b); // "b" is not defined