Java Pattern Class in the java.util.regex Package

Tags:

java.util.regex.Pattern provides the matches() method, which validates an input string against a regular expression.

Pattern Example

The following example checks whether an input string contains only numbers.

package com.devkuma.basic.java.util.regex;

import java.util.regex.Pattern;

public class PatternTutorial {
    public static void main(String[] args) {

        String regex = "[0-9]*$"; //numbers only

        String input1 = "0123456789"; //input string
        System.out.println(Pattern.matches(regex, input1));

        String input2 = "abcde56789"; //input string
        System.out.println(Pattern.matches(regex, input2));

        String input3 = "abcdefghij"; //input string
        System.out.println(Pattern.matches(regex, input3));
    }
}

Execution result:

true
false
false