e03-02.cpp

来自「游戏开发数据结构-Data.Structures.for.Game.Progra」· C++ 代码 · 共 57 行

// =======================================================
//  Chapter 3, Example 2
//  Demonstrating Dynamic Arrays.
// =======================================================
#include <malloc.h>

// -------------------------------------------------------
// Name:        ArrayFunction
// Description: sets array[0] to 10.
// Arguments:   - p_array: the array
// -------------------------------------------------------
void ArrayFunction( int p_array[] )
{
    p_array[0] = 10;
}



void main()
{
    // declare 3 array pointers, and set them to 0.
    int* array1 = 0;
    int* array2 = 0;
    int* array3 = 0;

    // allocate an array with 10 cells using malloc.
    array1 = (int*)malloc( 10 * sizeof(int) );

    // allocate an array with 10 cells using calloc.
    array2 = (int*)calloc( 10, sizeof(int) );

    // allocate an array with 10 cells using new.
    array3 = new int[10];


    // resize array1 and array2 using realloc.
    // note that the end of array2 will not have '0's in it.
    array1 = (int*)realloc( array1, 20 * sizeof(int) );
    array2 = (int*)realloc( array2, 20 * sizeof(int) );

    // resize array3 using the resize algorithm.
    int* temp = 0;
    int index;
    temp = new int[20];
    for( index = 0; index < 10; index++ )
         temp[index] = array3[index];
    delete[] array3;
    array3 = temp;
    temp = 0;

    // free the first two arrays using free.
    free( array1 );
    free( array2 );

    // free the third array using delete[]
    delete[] array3;
}