javascript里的"||"运算符与C/C++/Java/C#等静态类型语言里的语义不一样.
它的运算结果不是bool型的,而是任意类型的.
http://www.webreference.com/javascript/reference/core_ref/ops.html
[quote]
|| (Logical OR) Returns the first operand if it can be converted to true; otherwise, returns the second operand.
[/quote]