C语言 动态内存

数据类型	int	int*	double	double*	char	char*
字节大小	4	4	8	4	1	4

 

 

 

#include <stdio.h>
#include <stdlib.h>

int main()
{
    //一维 int double char 相同
    int n = 10;
    int *p = (int*)calloc(n,sizeof(int);
    free(p);
    p=NULL;
    //二维注意外围sizeof的形式,int double char 类似
    int n1 = 3, n2=3; 
    int **p = (int**)calloc(n1,sizeof(int*));
    for( int i =0; i <n1; i++)
    {
           p[i] = (int*)calloc(n2,sizeof(int); 
    }
    for( int i =0; i <n1; i++)
    {
           free(p[i]);
    }
    free(p);
    p = NULL;

}