Java tutorial
//package com.java2s; /* * Copyright 1999-2004 The Apache Software Foundation * * 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; import java.util.Iterator; public class Main { /** * Returns the number of occurrences of <i>obj</i> in <i>col</i>. */ public static int cardinality(Object obj, final Collection col) { int count = 0; Iterator it = col.iterator(); while (it.hasNext()) { Object elt = it.next(); if ((null == obj && null == elt) || obj.equals(elt)) { count++; } } return count; } }