关于正则表达式的问题 送分啦。

[tianyaofande]

字符串是这样子的：abc.<def.<2134.<165.7adf.<wqeri.<156
相信变成这样子：abc.<def.<2134.<165＋＋7adf.<wqeri.<156
也就是替换．但是点后面不可以有<
我的正则必表达式是这样子的：replaceFirst("(\\.)[^<]", "++");
但是把点后面的数字也给替换了。

[tianyaofande]

引用 1 楼 huntor 的回复:

"abc.<def.<2134.<165.7adf.<wqeri.<156".replaceFirst("\\.(?!<)", "++") abc.<def.<2134.<165++7adf.<wqeri.<156

哈哈，谢谢了，原来文档里面有呀。 Special constructs (non-capturing) (?:X) X, as a non-capturing group (?idmsux-idmsux) Nothing, but turns match flags id m su x on - off (?idmsux-idmsux:X) X, as a non-capturing group with the given flags i dm s ux on - off (?=X) X, via zero-width positive lookahead (?!X) X, via zero-width negative lookahead (?<=X) X, via zero-width positive lookbehind (?<!X) X, via zero-width negative lookbehind (?>X) X, as an independent, non-capturing group 好分是你的啦。

[huntor]

"abc.<def.<2134.<165.7adf.<wqeri.<156".replaceFirst("\\.(?!<)", "++") abc.<def.<2134.<165++7adf.<wqeri.<156

[huntor]

分拿来，这个是 Negative Lookahead