javascript子串

问题描述

最让人心寒的事！以下代码打印出'llo'而不是预期的'wo'。我得到了一些其他数字令人惊讶的结果。我在这里缺少什么？

  alert（'helloworld'.substring（5,2））; 
  

解决方案

你很困惑和 ： substring（）期望两个索引而不是偏移量和长度。在您的情况下，索引是5和2，即将返回字符2..4，因为排除了较高的索引。

the most darndest thing! the following code prints out 'llo' instead of the expected 'wo'. i get such surprising results for a few other numbers. what am i missing here?

alert('helloworld'.substring(5, 2));

解决方案

You're confusing substring() and substr(): substring() expects two indices and not offset and length. In your case, the indices are 5 and 2, ie characters 2..4 will be returned as the higher index is excluded.

这篇关于javascript子串的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持！