如何在Dart中使用RegEx？

In a Flutter application, I need to check if a string matches a specific RegEx. However, the RegEx I copied from the JavaScript version of the app always returns false in the Flutter app. I verified on regexr that the RegEx is valid, and this very RegEx is already being used in the JavaScript application, so it should be correct.

在Flutter应用程序中,我需要检查字符串是否与特定的RegEx匹配。但是,我从应用程序的JavaScript版本复制的RegEx在Flutter应用程序中始终返回false。我在regexr上验证了RegEx是有效的,并且这个RegEx已经在JavaScript应用程序中使用了,所以它应该是正确的。

Any help is appreciated!

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RegEx : /^WS{1,2}:\/\/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}:56789/i

RegEx:/^WS {1,2}:\ / / /\\ {{{{{{{{{{{{{{{{{{{{{{{ 56789 / I

Test Code :

测试代码:

RegExp regExp = new RegExp(
  r"/^WS{1,2}:\/\/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}:56789/i",
  caseSensitive: false,
  multiLine: false,
);
print("allMatches : "+regExp.allMatches("WS://127.0.0.1:56789").toString());
print("firstMatch : "+regExp.firstMatch("WS://127.0.0.1:56789").toString());
print("hasMatch : "+regExp.hasMatch("WS://127.0.0.1:56789").toString());
print("stringMatch : "+regExp.stringMatch("WS://127.0.0.1:56789").toString());

Output :

allMatches : ()
firstMatch : null
hasMatch : false
stringMatch : null

1 个解决方案

#1

I think you tried to include options in the raw expression string while you already have it as parameters to RegEx ( /i for case insensitivity is declared as caseSensitive: false).

我认为您尝试在原始表达式字符串中包含选项,而您已将它作为RegEx的参数(/ i表示不区分大小写被声明为caseSensitive:false)。

// Removed /i at the end
// Removed / in front - Thanks to Günter for warning
RegExp regExp = new RegExp(
  r"^WS{1,2}:\/\/\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}:56789",
  caseSensitive: false,
  multiLine: false,
);
print("allMatches : "+regExp.allMatches("WS://127.0.0.1:56789").toString());
print("firstMatch : "+regExp.firstMatch("WS://127.0.0.1:56789").toString());
print("hasMatch : "+regExp.hasMatch("WS://127.0.0.1:56789").toString());
print("stringMatch : "+regExp.stringMatch("WS://127.0.0.1:56789").toString());

Gives:

allMatches : (Instance of '_MatchImplementation')
firstMatch : Instance of '_MatchImplementation'
hasMatch : true
stringMatch : WS://127.0.0.1:56789