分配和使用无效用C免费二维数组 [英] Allocate and free 2D array in C using void

问题描述

的想法是仅使用两个功能，可以既分配和未在编译时已知的给定数据类型的分类的2D阵列。在code我在释放函数编写崩溃，但我不明白为什么。这里是code：

The idea is to use only two functions that can both allocate and free a 2D array of a given data type that is not known at compile-time. The code I have written crashes in the freeing function, but I cannot see why. Here is the code:

void** new2DArray(int row, int col, int typeSize){
    void** temp = malloc(sizeof(void*)*row); //EDIT                     
    for (row-=1; row >= 0; row--)                               
        temp[row] = malloc(typeSize*col);
    return temp; 
}


void free2DArray(void** array, int row, int typeSize){
    for (row -= 1; row >= 0; row--)
        free( *(array + row*typeSize) );
     free(array); 
}

在哪里，对于一个3x3阵列，是会被称为这样的：

Where, for a 3x3 array, is would be called like:

double** test = (double**) new2DArray(3, 3, sizeof(double));
free2DArray(test, 3, sizeof(double));

这有什么错，立即与释放功能？

Is there anything immediately wrong with the freeing function?

推荐答案

的 free2DArray 看起来是错误的。不需要知道类型的大小;你只需释放你分配的块：

The free2DArray looks wrong. You don't need to know the size of the types; you just free the blocks that you allocated:

void free2DArray(void** array, int row){
    for (row -= 1; row >= 0; row--)
        free( array[row] );
     free(array); 
}

这篇关于分配和使用无效用C免费二维数组的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！