checkPattern function

String? checkPattern(
  1. String? input,
  2. Pattern pt, {
  3. String? errMsg = "Please enter valid information",
})

Implementation

String? checkPattern(String? input,Pattern pt,{String? errMsg="Please enter valid information"}){
  RegExp regExp = RegExp(pt as String);
  if (input==null||!regExp.hasMatch(input)) {
    return errMsg;}
  return null;
}