Java tutorial
//package com.java2s; /* * Copyright 2010 Vamonos Software * * Licensed under the Apache License, Version 2.0 (the "License"); * you may not use this file except in compliance with the License. * You may obtain a copy of the License at * * http://www.apache.org/licenses/LICENSE-2.0 * * Unless required by applicable law or agreed to in writing, software * distributed under the License is distributed on an "AS IS" BASIS, * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. * See the License for the specific language governing permissions and * limitations under the License. */ import java.util.Collection; public class Main { /** * Null safe summation of the sizes of all of the given collections */ public static int size(Collection... collections) { int size = 0; if (collections != null) { for (Collection collection : collections) { if (collection != null) size += collection.size(); } } return size; } }