[問題] mem_alloc及mem_free的對應問題
#include<stdlib.h>
#include<stdio.h>
/*
要注意mem_alloc及mem_free的對應，要用方法發現或防止忘了mem free。
*/
void mem_free(int *);
int main(void)
{
int *ptr;
ptr=(int *)malloc(sizeof(int));
*ptr=1000;
printf("%d\n",*ptr);
mem_free(ptr);
*ptr=5;
printf("%d\n",*ptr);
system("pause");
return 0;
}
void mem_free(int *ptr1)
{
if(ptr1!=NULL)
{
free(ptr1);
ptr1=NULL;
}
//*ptr1=5;
}
此程式出來的答案是
1000
5
但是有疑問的就是在主程式的mem_free(ptr);下面
明明已經把mem_free了
為何可以使用*ptr=5 設值
但若是在mem_free(int *ptr1) function中的最後
若是設成*ptr1=5 卻會interrupt ?
這是什麼原因呢???
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