为什么String.matches在Java中返回false？ [英] Why is String.matches returning false in Java?

问题描述

if("test%$@*)$(%".matches("[^a-zA-Z\\.]"))
    System.exit(0);

if("te/st.txt".matches("[^a-zA-Z\\.]"))
    System.exit(0);

即使正则表达式应该返回true，程序也不会退出。代码出了什么问题？

The program isn't exiting even though the regexes should be returning true. What's wrong with the code?

推荐答案

匹配返回 true 仅当整个字符串与正则表达式匹配时。在您的情况下，您的正则表达式仅代表一个字符，该字符不是 az ， AZ 或 。

matches returns true only if entire string matches regex. In your case your regex represents only one character that is not a-z, A-Z or ..

我怀疑你想检查字符串是否包含你在regex中描述的这些特殊字符之一。在这种情况下，使用。* 围绕正则表达式，让正则表达式匹配整个字符串。哦，你不必逃避。里面的字符类 [。] 。

I suspect that you want to check if string contains one of these special characters which you described in regex. In that case surround your regex with .* to let regex match entire string. Oh, and you don't have to escape . inside character class [.].

if ("test%$@*)$(%".matches(".*[^a-zA-Z.].*")) {
    //string contains character that is not in rage a-z, A-Z, or '.'

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