sizeof的几个实例

#include "stdio.h"
typedef unsigned long DWORD;
typedef struct tagICMPHDR
{
	unsigned char Type;
	unsigned char Code;
	unsigned short Checksum;
	unsigned short ID;
	unsigned short Seq;
	char Data;
}ICMPHDR;
typedef struct tagECHORE
{
	ICMPHDR icmpHdr;
	DWORD dwTime;
	char cData[32];
}ECHOREQUEST;
void main()
{
    ECHOREQUEST est;
    printf("%d\n",sizeof(est));
}

上面的代码输出是什么呢？

答案是 48 ,

sizeof(ICMPHDR)答案是10 ,sizeof(DWORD)=4,sizeof(cData)等于多少？是个数组，我们知道sizeof(char)是1,所以sizeof(cData)为32.

如果你有不同的答案或不能理解就给我留言