[英]Javascript Confusing Regex Groups
I have regular expression which works great on regexr.com , but does not work with Javascript. 我有一个正则表达式,它在regexr.com上很好用,但不适用于Javascript。
Here is the link to regexr http://regexr.com/3b780 这是regexr的链接http://regexr.com/3b780
Below is my Javascript attempt 以下是我的Javascript尝试
var expression="--user=foo:This is description"
var regexExp = new RegExp("(?:=)(.[^:]+)|(?::)(.[^=]+)|(.[^=^:]+)","g");
console.log(regexExp.exec(expression))
Which returns 哪个返回
[ '--user',
undefined,
undefined,
'--user',
index: 0,
input: '--user=foo:This is description'
]
[ '--user',
'foo',
'This is description',
'--user',
index: 0,
input: '--user=foo:This is description'
]
RegExp#exec
with a global regular expression needs to be called multiple times to get all matches . 具有全局正则表达式的RegExp#exec
需要多次调用以获取所有匹配项 。 You can get closer with String#match
(use a regular expression literal, by the way): 您可以更接近String#match
(顺便说一下,使用正则表达式文字):
var expression = "--user=foo:This is description";
var re = /(?:=)(.[^:]+)|(?::)(.[^=]+)|(.[^=^:]+)/g;
console.log(expression.match(re));
which results in: 结果是:
Array [ "--user", "=foo", ":This is description" ]
However, that's a very unusual regular expression. 但是,这是一个非常不寻常的正则表达式。 The non-capturing groups are useless, the capturing groups are never part of the same match, and [^=^:]
probably doesn't have the intended effect. 非捕获组是无用的,捕获组永远不会属于同一匹配项,并且[^=^:]
可能没有预期的效果。 Maybe something like this, instead? 也许像这样吧?
var re = /(--.+?)=(.+?):(.+)/;
var expression = "--user=foo:This is description";
console.log(re.exec(expression));
resulting in: 导致:
Array [ "--user=foo:This is description", "--user", "foo", "This is description" ]
声明:本站的技术帖子网页,遵循CC BY-SA 4.0协议,如果您需要转载,请注明本站网址或者原文地址。任何问题请咨询:yoyou2525@163.com.