Android Array Sub Array subarray(double[] array, int startIndexInclusive, int endIndexExclusive)

Description

Produces a new double array containing the elements between the start and end indices.

The start index is inclusive, the end index exclusive.

License

Apache License

Parameter

Parameter	Description
array	the array
startIndexInclusive	the starting index. Undervalue (<0) is promoted to 0, overvalue (>array.length) results in an empty array.
endIndexExclusive	elements up to endIndex-1 are present in the returned subarray. Undervalue (< startIndex) produces empty array, overvalue (>array.length) is demoted to array length.

Return

a new array containing the elements between the start and end indices.

Declaration

public static double[] subarray(double[] array,
        int startIndexInclusive, int endIndexExclusive)

Method Source Code

//package com.java2s;
/*// w ww . ja va  2  s.co m
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You 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;

public class Main {
    /**
     * An empty immutable <code>long</code> array.
     */
    public static final long[] EMPTY_LONG_ARRAY = new long[0];
    /**
     * An empty immutable <code>int</code> array.
     */
    public static final int[] EMPTY_INT_ARRAY = new int[0];
    /**
     * An empty immutable <code>short</code> array.
     */
    public static final short[] EMPTY_SHORT_ARRAY = new short[0];
    /**
     * An empty immutable <code>byte</code> array.
     */
    public static final byte[] EMPTY_BYTE_ARRAY = new byte[0];
    /**
     * An empty immutable <code>double</code> array.
     */
    public static final double[] EMPTY_DOUBLE_ARRAY = new double[0];
    /**
     * An empty immutable <code>float</code> array.
     */
    public static final float[] EMPTY_FLOAT_ARRAY = new float[0];
    /**
     * An empty immutable <code>boolean</code> array.
     */
    public static final boolean[] EMPTY_BOOLEAN_ARRAY = new boolean[0];
    /**
     * An empty immutable <code>char</code> array.
     */
    public static final char[] EMPTY_CHAR_ARRAY = new char[0];

    /**
     * <p>Produces a new array containing the elements between
     * the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * <p>The component type of the subarray is always the same as
     * that of the input array. Thus, if the input is an array of type
     * <code>Date</code>, the following usage is envisaged:</p>
     *
     * <pre>
     * Date[] someDates = (Date[])ArrayUtils.subarray(allDates, 2, 5);
     * </pre>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static <T> T[] subarray(T[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        Class<?> type = array.getClass().getComponentType();
        if (newSize <= 0) {
            @SuppressWarnings("unchecked")
            // OK, because array is of type T
            final T[] emptyArray = (T[]) Array.newInstance(type, 0);
            return emptyArray;
        }
        @SuppressWarnings("unchecked")
        // OK, because array is of type T
        T[] subarray = (T[]) Array.newInstance(type, newSize);
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>long</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static long[] subarray(long[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_LONG_ARRAY;
        }

        long[] subarray = new long[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>int</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static int[] subarray(int[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_INT_ARRAY;
        }

        int[] subarray = new int[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>short</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static short[] subarray(short[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_SHORT_ARRAY;
        }

        short[] subarray = new short[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>char</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static char[] subarray(char[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_CHAR_ARRAY;
        }

        char[] subarray = new char[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>byte</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static byte[] subarray(byte[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_BYTE_ARRAY;
        }

        byte[] subarray = new byte[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>double</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static double[] subarray(double[] array,
            int startIndexInclusive, int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_DOUBLE_ARRAY;
        }

        double[] subarray = new double[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>float</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static float[] subarray(float[] array, int startIndexInclusive,
            int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_FLOAT_ARRAY;
        }

        float[] subarray = new float[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }

    /**
     * <p>Produces a new <code>boolean</code> array containing the elements
     * between the start and end indices.</p>
     *
     * <p>The start index is inclusive, the end index exclusive.
     * Null array input produces null output.</p>
     *
     * @param array  the array
     * @param startIndexInclusive  the starting index. Undervalue (&lt;0)
     *      is promoted to 0, overvalue (&gt;array.length) results
     *      in an empty array.
     * @param endIndexExclusive  elements up to endIndex-1 are present in the
     *      returned subarray. Undervalue (&lt; startIndex) produces
     *      empty array, overvalue (&gt;array.length) is demoted to
     *      array length.
     * @return a new array containing the elements between
     *      the start and end indices.
     * @since 2.1
     */
    public static boolean[] subarray(boolean[] array,
            int startIndexInclusive, int endIndexExclusive) {
        if (array == null) {
            return null;
        }
        if (startIndexInclusive < 0) {
            startIndexInclusive = 0;
        }
        if (endIndexExclusive > array.length) {
            endIndexExclusive = array.length;
        }
        int newSize = endIndexExclusive - startIndexInclusive;
        if (newSize <= 0) {
            return EMPTY_BOOLEAN_ARRAY;
        }

        boolean[] subarray = new boolean[newSize];
        System.arraycopy(array, startIndexInclusive, subarray, 0, newSize);
        return subarray;
    }
}