问题描述
JavaScript 是否支持正面和/或负面的前瞻/后视?它们的哪些组合?或者，更具体地说:
Does JavaScript support positive and/or negative lookaheads/lookbehinds? Which combinations of them? Or, to be more specific:
- 正面展望
- 负面预测
- 正面回顾
- 负面回顾
推荐答案
Javascript 仅支持正面和负面的前瞻，不支持任何后视，但您仍然可以在 Javascript 中使用回调.
Javascript has support for only positive and negative lookahead with no support whatsoever for lookbehinds, but you can still mimic the latter in Javascript using callbacks.
有一篇关于这个的好文章这里，实际上虽然本文使用回调来为lookbehind提供某种替代支持，但同样的原理也可以用于其他支持lookbehind但不支持变量表达式的语言，所以这是一个方便的技巧.
There is a nice article about this here, actually although this article uses callbacks to provide some sort of an alternative support for lookbehind, the same principle can be used in other languages that support lookbehinds but not variable expressions in them so it is handy trick.
这篇关于JavaScript 对正则表达式中的 Lookaheads 和 Lookbehinds 的支持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！