Inserts the specified element at the specified position in the double-type-value array. : Array Insert Remove « Collections Data Structure « Java

1. Java
2. Collections Data Structure
3. Array Insert Remove

Inserts the specified element at the specified position in the double-type-value array.

      
/*   Copyright 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.lang.reflect.Array;


/**
 * <p>Operations on arrays, primitive arrays (like <code>int[]</code>) and
 * primitive wrapper arrays (like <code>Integer[]</code>).</p>
 * 
 * <p>This class tries to handle <code>null</code> input gracefully.
 * An exception will not be thrown for a <code>null</code>
 * array input. However, an Object array that contains a <code>null</code>
 * element may throw an exception. Each method documents its behaviour.</p>
 *
 * @author Stephen Colebourne
 * @author Moritz Petersen
 * @author <a href="mailto:fredrik@westermarck.com">Fredrik Westermarck</a>
 * @author Nikolay Metchev
 * @author Matthew Hawthorne
 * @author Tim O'Brien
 * @author Pete Gieser
 * @author Gary Gregory
 * @author <a href="mailto:equinus100@hotmail.com">Ashwin S</a>
 * @author Maarten Coene
 * @since 2.0
 * @version $Id: ArrayUtils.java 632503 2008-03-01 00:21:52Z ggregory $
 */
public class Main {
  
  
  /**
   * <p>Inserts the specified element at the specified position in the array. 
   * Shifts the element currently at that position (if any) and any subsequent
   * elements to the right (adds one to their indices).</p>
   *
   * <p>This method returns a new array with the same elements of the input
   * array plus the given element on the specified position. The component 
   * type of the returned array is always the same as that of the input 
   * array.</p>
   *
   * <p>If the input array is <code>null</code>, a new one element array is returned
   *  whose component type is the same as the element.</p>
   * 
   * <pre>
   * ArrayUtils.add([1.1], 0, 2.2)              = [2.2, 1.1]
   * ArrayUtils.add([2.3, 6.4], 2, 10.5)        = [2.3, 6.4, 10.5]
   * ArrayUtils.add([2.6, 6.7], 0, -4.8)        = [-4.8, 2.6, 6.7]
   * ArrayUtils.add([2.9, 6.0, 0.3], 2, 1.0)    = [2.9, 6.0, 1.0, 0.3]
   * </pre>
   * 
   * @param array  the array to add the element to, may be <code>null</code>
   * @param index  the position of the new object
   * @param element  the object to add
   * @return A new array containing the existing elements and the new element
   * @throws IndexOutOfBoundsException if the index is out of range 
   * (index < 0 || index > array.length).
   */
  public static double[] add(double[] array, int index, double element) {
      return (double[]) add(array, index, new Double(element), Double.TYPE);
  }
  
  /**
   * Underlying implementation of add(array, index, element) methods. 
   * The last parameter is the class, which may not equal element.getClass 
   * for primitives.
   *
   * @param array  the array to add the element to, may be <code>null</code>
   * @param index  the position of the new object
   * @param element  the object to add
   * @param clss the type of the element being added
   * @return A new array containing the existing elements and the new element
   */
  private static Object add(Object array, int index, Object element, Class clss) {
      if (array == null) {
          if (index != 0) {
              throw new IndexOutOfBoundsException("Index: " + index + ", Length: 0");
          }
          Object joinedArray = Array.newInstance(clss, 1);
          Array.set(joinedArray, 0, element);
          return joinedArray;
      }
      int length = Array.getLength(array);
      if (index > length || index < 0) {
          throw new IndexOutOfBoundsException("Index: " + index + ", Length: " + length);
      }
      Object result = Array.newInstance(clss, length + 1);
      System.arraycopy(array, 0, result, 0, index);
      Array.set(result, index, element);
      if (index < length) {
          System.arraycopy(array, index, result, index + 1, length - index);
      }
      return result;
  }

}

   
    
    
    
    
    
  

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