Question

如果想排除“pple”的话,为什么我可以 use(!y)pple?

What is alternative to (?!y) before a word?

http://jsfiddle.net/ksevelyar/SbCCx/4/

Answer 1

www.un.org/Depts/DGACM/index_spanish.htm 回答你原来的问题:。

您可以精-地加入“由任何东西(str)或非自然特性所取代”的编码。

/(?:^|[^y])apple/

或视你想要做些什么,你可以使用一字边界匹配。

/apple/

matches the boundary between an alphanumeric character (w) and a non-alphanumeric character (W)

其他一些环境(如Perl)有时具有这种眼光背后的功能,很容易地建立在以下方面:

/(?=)/   positive lookahead
/(?!)/   negative lookahead
/(?<=)/  positive lookbehind
/(?<!)/  negative lookbehind

www.un.org/Depts/DGACM/index_spanish.htm 关于在之前不替换物品的问题

或许,如果你进行两个步骤:首先从你身上删除<代码><pre>内的所有案文,然后进行替换,然后在你完成之后添加隐藏的文本。

Answer 2

(?!) is a lookahead, which will look over the end of their regex to seek (or not found, in this case because its a anti-lookahead) nature.

You probably wanted to write a lookbehind, or (?<!...). Something like /(?<!y)apple/, however they aren t supported by the javascript regular expression engine.

但是,看不到替代物的答案,但是,如果不更好地了解你试图做些什么,就很难相互建议。

Answer 3

JavaScript s regexp is not the best one... Here is a (very) dirty workaround which might suit you:

str = str.replace(/<pre>apple</pre>/g, "#DUMMY#");
str = str.replace(/apple/g, "sword");
str = str.replace(/#DUMMY#/g, "<pre>apple</pre>");

http://jsfiddle.net/pZ3c9/"rel=“nofollow> http://jsfiddle.net/pZ3c9/。

希望这将有助于你们!

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