Program to check if a character is a number / digit in Java
package com.hubberspot.example; public class IsNumberTest { public static void main(String[] args) { // Create a String of character having numbers // in between just for a test String characters = "q1w2E3r4T5y 6!7@8#9$0%-^"; // we take the length of characters by length() int length = characters.length(); // we than loop each character one by one for(int i = 0; i < length; i++) { // we store each character in a variable // for each loop char character = characters.charAt(i); // checking for each character that its a number or not // by calling Character class isDigit() method , by passing // the character. It returns true if the character passed is // digit or a number if(Character.isDigit(character)) { System.out.println("Given character at index " + i + " is a number"); } else { System.out.println("Given character at index " + i + " is not a number"); } } } }Output of the program :