substring(indexA, indexB) 的官方解释不明白
Parameters
indexA
An integer between 0 and 1 less than the length of the string.
indexB
An integer between 0 and 1 less than the length of the string.
这一段“between 0 and 1”,为什么要是这样呢?我查了一下官方资料
http://devedge.netscape.com/central/javascript/
JavaScript 1.5/1.4/1.3 Reference 全是这样说,如果文档有错那这个错误的生命周期也太长了吧!