// strings/IntegerMatch.java

// (c)2021 MindView LLC: see Copyright.txt

// We make no guarantees that this code is fit for any purpose.

// Visit http://OnJava8.com for more book information.

import java.util.stream.*;

public class IntegerMatch {

public static void main(String[] args) {

String possiblyMinus = "-?\\d+";

Stream.of(

"-1234".matches(possiblyMinus),

"5678".matches(possiblyMinus),

"+911".matches(possiblyMinus),

"+911".matches("(-|\\+)?\\d+")

).forEach(System.out::println);

}

}

/* Output:

true

true

false

true

*/