动态创建和释放二维数组

#define _CRT_SECURE_NO_WARNINGS
#include<stdio.h>
#include<string.h>
#include<stdlib.h>

//动态创建二维数组，三级指针做输出
int get2DArr(char*** arr/*out*/, int row, int col) {
	;
	char** p = NULL;//辅助指针
	p = (char**)malloc(sizeof(char*)*row);

	for (int i = 0; i < row; i++) {
		p[i] = (char*)malloc(sizeof(char)*col);
	}

	for (int i = 0; i < row; i++) {//初始化
		for (int j = 0; j < col; j++) {
			p[i][j] = i + j + 1;
		}
	}
	*arr = p;//挂上
	return 0;
}
//完全释放二维数组（释放所指内存空间，并将自身值设为NULL），三级指针做输入
int free2DArr(char*** arr, int row) {
	char** p = *arr;//用辅助指针接收，便于操作
	//1.释放一级指针
	for (int i = 0; i < row; i++) {
		if (p[i] != NULL)
		{
			free(p[i]);
			p[i] = NULL;
		}
	}
	//2.释放二级指针
	if (*arr != NULL)
	{
		free(*arr);//读
		*arr = NULL;//写
	}
	return 0;
}

int main() {
	char** arr = NULL;
	get2DArr(&arr, 2, 3);

	for (int i = 0; i < 2; i++) {
		for (int j = 0; j < 3; j++) {
			printf("%d", arr[i][j]);
		}
		printf("\n");
	}
	free2DArr(&arr, 2);

	system("pause");
	return 0;

}