Check out example codes for "regex dart". It will help you in understanding the concepts better.

Code Example 1

RegExp exp = new RegExp(r"(\w+)");
String str = "Parse my string";
Iterable<RegExpMatch> matches = exp.allMatches(str);

Code Example 2

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());

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

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