Mega Code Archive
Append item to array
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//Copyright 2007-2009 David Yu dyuproject@gmail.com
//------------------------------------------------------------------------
//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.
//package com.dyuproject.util;
import java.lang.reflect.Array;
/**
* @author David Yu
* @created Jan 16, 2009
*/
public final class ArrayUtil
{
/**
* Copies the elements of the {@code oldArray} to a new array with extra space to
* append the given element {@code toAppend}.
*/
@SuppressWarnings("unchecked")
public static <T> T[] append(T[] oldArray, T toAppend)
{
Class<?> component = oldArray.getClass().getComponentType();
T[] array = (T[])Array.newInstance(component, oldArray.length+1);
System.arraycopy(oldArray, 0, array, 0, oldArray.length);
array[oldArray.length] = toAppend;
return array;
}
/**
* Copies the elements of the {@code oldArray} to a new array with extra space to
* append the given element {@code toAppend1} and the array {@code toAppend2}.
*/
@SuppressWarnings("unchecked")
public static <T> T[] append(T[] oldArray, T toAppend1, T[] toAppend2)
{
Class<?> component = oldArray.getClass().getComponentType();
T[] array = (T[])Array.newInstance(component,
oldArray.length + 1 + toAppend2.length);
System.arraycopy(oldArray, 0, array, 0, oldArray.length);
array[oldArray.length] = toAppend1;
System.arraycopy(toAppend2, 0, array, oldArray.length+1, toAppend2.length);
return array;
}
/**
* Copies the elements of the {@code oldArray} to a new array with extra space to
* append the given array {@code toAppend}.
*/
@SuppressWarnings("unchecked")
public static <T> T[] append(T[] oldArray, T[] toAppend)
{
Class<?> component = oldArray.getClass().getComponentType();
T[] array = (T[])Array.newInstance(component,
oldArray.length + toAppend.length);
System.arraycopy(oldArray, 0, array, 0, oldArray.length);
System.arraycopy(toAppend, 0, array, oldArray.length, toAppend.length);
return array;
}
/**
* Copies the elements of the {@code oldArray} to a new array with extra space to
* append the given array {@code toAppend1} and the element {@code toAppend2}.
*/
@SuppressWarnings("unchecked")
public static <T> T[] append(T[] oldArray, T[] toAppend1, T toAppend2)
{
Class<?> component = oldArray.getClass().getComponentType();
T[] array = (T[])Array.newInstance(component,
oldArray.length + toAppend1.length + 1);
System.arraycopy(oldArray, 0, array, 0, oldArray.length);
System.arraycopy(toAppend1, 0, array, oldArray.length, toAppend1.length);
array[array.length-1] = toAppend2;
return array;
}
/**
* Copies the elements of the {@code oldArray} to a new array with extra space to
* append the given array {@code toAppend1} and the array {@code toAppend2}.
*/
@SuppressWarnings("unchecked")
public static <T> T[] append(T[] oldArray, T[] toAppend1, T[] toAppend2)
{
Class<?> component = oldArray.getClass().getComponentType();
T[] array = (T[])Array.newInstance(component,
oldArray.length + toAppend1.length + toAppend2.length);
System.arraycopy(oldArray, 0, array, 0, oldArray.length);
System.arraycopy(toAppend1, 0, array, oldArray.length, toAppend1.length);
System.arraycopy(toAppend2, 0, array, oldArray.length + toAppend1.length, toAppend2.length);
return array;
}
/**
* Returns a copy of the old array {@code oldArray} but with the element at the
* give index {@code idx} removed.
*
* @throws {@link IllegalArgumentException} if the array index is out of bounds.
*/
@SuppressWarnings("unchecked")
public static <T> T[] remove(T[] oldArray, int idx)
{
if(idx<0 || idx>=oldArray.length)
throw new IllegalArgumentException("array index " + idx + " out of bounds");
Class<?> component = oldArray.getClass().getComponentType();
T[] array = (T[])Array.newInstance(component, oldArray.length-1);
if(idx==0)
System.arraycopy(oldArray, 1, array, 0, array.length);
else
{
System.arraycopy(oldArray, 0, array, 0, idx);
System.arraycopy(oldArray, idx+1, array, idx, array.length-idx);
}
return array;
}
}
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