字符串中，有些特殊字符，叫做字面量，常见的字面量如下表：
text.length; 10
var a = ‘Java‘; undefined var b = ‘Script‘; undefined var c = a+b; undefined c "JavaScript"
var t = 123; undefined t.toString(); "123"
t.toString(2);
"1111011"
原文：http://www.cnblogs.com/leomei91/p/7457078.html