Here you can find the source of length(String source)
public static int length(String source)
//package com.java2s; /* MarcWorx MARC Library - Utilities for manipulation of MARC records Copyright (C) 2013 Todd Walker, Talwood Solutions This program is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation, either version 3 of the License, or (at your option) any later version./*w ww . jav a 2 s .c om*/ This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program. If not, see <http://www.gnu.org/licenses/>. */ public class Main { public static int length(String source) { int result = 0; if (isNotEmpty(source)) { result = source.length(); } return result; } public static boolean isNotEmpty(String str) { return !isEmpty(str); } public static boolean isEmpty(String str) { return (str == null || str.length() == 0); } }