Javascript 不会使用正则表达式进行分割
自从我开始写这个问题以来，我想我已经找到了每个问题的答案，但我想我还是会发布，因为它可能对其他人有用，而且更多的澄清可能会有所帮助。
我试图将正则表达式与 javascript 函数 split 一起使用。 由于某种原因，即使当我调用 match 时它找到了匹配项，它也没有拆分字符串。 我最初认为问题出在我的正则表达式中使用前瞻。 这是一个简化的示例：
不起作用：
"aaaaBaaaa".split("(?=B).");
起作用：
"aaaaBaaaa".match("(?=B).");
问题似乎是在拆分示例中，传递的字符串没有被解释为正则表达式。 使用正斜杠而不是引号似乎可以解决问题。
"aaaaBaaaa".split(/(?=B)./);
我用下面这个看起来很傻的例子证实了我的理论：
"aaaaaaaa(?=B).aaaaaaa".split("(?=B).");
有没有人认为 match 函数假设你有正则表达式而 split 函数没有，这很奇怪？
Since I started writing this question, I think I figured out the answers to every question I had, but I thought I'd post anyway, as it might be useful to others and more clarification might be helpful.
I was trying to use a regular expression with lookahead with the javascript function split. For some reason it was not splitting the string even though it finds a match when I call match. I originally thought the problem was from using lookahead in my regular expression. Here is a simplified example:
Doesn't work:
"aaaaBaaaa".split("(?=B).");
Works:
"aaaaBaaaa".match("(?=B).");
It appears the problem was that in the split example, the passed string wasn't being interpreted as a regular expression. Using forward slashes instead of quotes seems to fix the problem.
"aaaaBaaaa".split(/(?=B)./);
I confirmed my theory with the following silly looking example:
"aaaaaaaa(?=B).aaaaaaa".split("(?=B).");
Does anyone else think it's strange that the match function assumes you have a regular expression while the split function does not?
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String.split接受字符串或正则表达式作为其第一个参数。String.match方法仅接受正则表达式。我想
String.match将尝试处理传递的任何内容； 因此，如果您传递一个字符串，它会将其解释为正则表达式。String.split方法无法做到这一点，因为它可以接受正则表达式和字符串； 在这种情况下，事后猜测是愚蠢的。编辑：（来自：“JavaScript：权威指南”）
String.match需要使用正则表达式。 传递的参数必须是一个RegExp对象，用于指定要匹配的模式。 如果此参数不是RegExp，则首先通过将其传递给RegExp()将其转换为一个构造函数。String.splitaccepts either a string or regular expression as its first parameter. TheString.matchmethod only accepts a regular expression.I'd imagine that
String.matchwill try and work with whatever is passed; so if you pass a string it will interpret it as a regular expression. TheString.splitmethod doesn't have the luxury of doing this because it can accept regular expressions AND strings; in this case it would be foolish to second-guess.Edit: (From: "JavaScript: The Definitive Guide")
String.matchrequires a regular expression to work with. The passed argument needs to be aRegExpobject that specifies the pattern to be matched. If this argument is not aRegExp, it is first converted to one by passing it to theRegExp()constructor.如果我没记错的话（这里我可能是错的），在正则表达式引擎被广泛使用之前， split 方法是在 javascript 中实现的，所以它可能是为了向后兼容。
If I recall correctly (and I could be very wrong here), the split method was implemented in javascript before the regex engine was in wide use, so it's presumably for backward compatibility.