Here you can find the source of lengthOf(T[] array)
public static <T> int lengthOf(T[] array)
//package com.java2s; /*/* w ww . ja va 2s . c o m*/ * * Managed Data Structures * Copyright ? 2016 Hewlett Packard Enterprise Development Company LP. * * This program is free software: you can redistribute it and/or modify * it under the terms of the GNU Lesser General Public License as published by * the Free Software Foundation, either version 3 of the License, or * (at your option) any later version. * * 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 Lesser General Public License for more details. * * You should have received a copy of the GNU Lesser General Public License * along with this program. If not, see <http://www.gnu.org/licenses/>. * * As an exception, the copyright holders of this Library grant you permission * to (i) compile an Application with the Library, and (ii) distribute the * Application containing code generated by the Library and added to the * Application during this compilation process under terms of your choice, * provided you also meet the terms and conditions of the Application license. * */ public class Main { public static <T> int lengthOf(T[] array) { return array == null ? 0 : array.length; } }