Write code to remove Non Digits from a string
//package com.book2s; public class Main { public static void main(String[] argv) { String text = "book2s.com"; System.out.println(removeNonDigits(text)); }/*from w w w.j a va2 s . c o m*/ public static String removeNonDigits(String text) { if (text == null) return null; StringBuilder sb = new StringBuilder(); for (int i = 0; i < text.length(); i++) { if (Character.isDigit(text.charAt(i))) { sb.append(text.charAt(i)); } } return sb.toString(); } }