Java Collection Search indexOfObjectIdentity(Collection collection, Object object)

Here you can find the source of indexOfObjectIdentity(Collection collection, Object object)

Description

Returns the index position of the first occurring object within the Collection .

License

Apache License

Parameter

Parameter Description
collection a parameter
object a parameter

Return

index position of the first matching element;-1 if no element is matching

Declaration

public static <E> int indexOfObjectIdentity(Collection<E> collection, Object object) 

Method Source Code

//package com.java2s;
/*******************************************************************************
 * Copyright 2011 Danny Kunz//from www  . j av a 2 s . c  om
 * 
 * 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 index position of the first occurring object within the {@link Collection}. Comparisons uses the
     * "object == element" instead of the "equals" method to determine the object identity.
     * 
     * @param collection
     * @param object
     * @return index position of the first matching element;-1 if no element is matching
     */
    public static <E> int indexOfObjectIdentity(Collection<E> collection, Object object) {
        //
        int retval = -1;

        //
        if (collection != null) {
            Iterator<E> iterator = collection.iterator();
            if (iterator != null) {
                int indexPosition = 0;
                while (retval < 0 && iterator.hasNext()) {
                    //
                    E element = iterator.next();
                    if (element == object) {
                        retval = indexPosition;
                    }

                    //
                    indexPosition++;
                }
            }
        }

        //
        return retval;
    }
}

Related

  1. hasValidElement(Collection collection)
  2. hasValue(Collection collection)
  3. indexOf(Collection stringCollection, String str)
  4. indexOf(final Collection c, final Object elem)
  5. indexOfInstance(final Collection collection, final T instance)