Match and extract special word in Dart - dart

Question

I tried to manipulate a text to match and extract special or some words in Dart. For example:
I want to check matching of words ends with a given word
String oldText = "website or show me to";
String newText = "show me to tell";
if (oldText.trim().endsWith(newText.trim())) {
final extractText = oldText.trim().substring(newText.length);
print(extractText);
} else {
print("Not matched");
}
I want to extract only word - "tell" so how can I do it? Need to use Regular expression?

Answer 1

Take a look here. I've implemented a regex which will check that tell is followed by end of line $. The regex is probably easier than any other method you might try, plus it's easy to change if conditions change.
void main() {
String oldText = "website or show me to";
String newText = "show me to tell";
RegExp parser = RegExp(r"tell$");
if (parser.hasMatch(oldText)) {
print(parser.stringMatch(oldText).toString());
} else {
print("Not matched");
}
if (parser.hasMatch(newText)) {
print(parser.stringMatch(newText).toString());
} else {
print("Not matched");
}
}
And here is an example where I have removed the check to a function and also set it up so that you can dynamically generate the regex:
void main() {
String oldText = "website or show me to";
String newText = "show me to tell";
String test = "tell";
RegExp parser = RegExp(test+r"$");
print(checkMatch(oldText, parser));
print(checkMatch(newText, parser));
}
checkMatch(text, parser) {
if (parser.hasMatch(text)) {
return(parser.stringMatch(text).toString());
} else {
return("Not matched");
}
}