NSPredicate带有问号崩溃 [英] NSPredicate crashed with question mark

问题描述

我有一个NSPredicate看起来像这样...

I have a NSPredicate which looks like this ...

NSPredicate *predicate = [NSPredicate predicateWithFormat : @"keyword MATCHES[c] %@", theKeyword]; 

其中
theKeyword = @？;

谓词坠毁时出现以下异常...

The predicate crashed with the following exception ...

Terminating app due to uncaught exception 'NSInvalidArgumentException', reason: 'Can't do regex matching, reason: (Can't open pattern U_REGEX_RULE_SYNTAX (string D;rdz;oirnodzirngzdorngzdorngzdrjgnz@dorjn
Isdjfij
Fisdjfisj
Jsifjsijfs
Ifjifjs
Isjfidsj
Fjisjfi
, pattern ？, case 1, canon 2))'

有人知道为什么它不工作吗？
感谢所有帮助>

Does anybody know why it just won't work? Thanks for all the help >"<

推荐答案

我不熟悉 NSPredicate ，但如果？应该是正则表达式，那么它是无效的。问号是一个量词，意思是

I'm not familiar with NSPredicate, but if ? is supposed to be a regular expression, then it's invalid. The question mark is a quantifier, meaning "zero or one instances of the previous token" - and there is no token to repeat. What do you want your regex to do?

如果你想匹配一个字面的问号，那么你的正则表达式需要使用反斜杠转义它（regex literal： \？，regex string： \\？）

If you want to match a literal question mark, then you need to escape it using backslashes (regex literal: \?, regex string: \\?)

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