C语言中sizeof()求字节数的应用举例

本文尽可能多的测试了在Win32平台下用sizeof()求各种类型变量字节数的结果，而且会不断更新。很有参考价值哦！

 sizeof(char)=1
 sizeof(short)=2
 sizeof(int)=4
 sizeof(long)=4
 sizeof(float)=4
 sizeof(double)=8
 sizeof(long double)=8
 
sizeof(unsigned char)=1
 sizeof(unsigned short)=2
 sizeof(unsigned int)=4
 sizeof(unsigned long)=4
 sizeof(unsigned float)=4
 sizeof(unsigned double)=4
 sizeof(unsigned long double)=8
 

char a[] = {'a','b','c','d','e'};//sizeof(a)=5
 char b[] = "abcde";//sizeof(b)=6
 char c[][3] = {{'a','b','c'},{'d','e','f'},{'g','h','i'},{'j','k','l'}};
 //sizeof(c)=12
 //sizeof(c[0])=3
 //sizeof(c[0][0])=1
 char d[][5] = {"abcc","deff","ghii","jkll"};
 //sizeof(d)=20
 //sizeof(d[0])=5
 //sizeof(d[0][0])=1
 char *p = 0;//sizeof(p)=4
 char *q = (char *)malloc(5);//sizeof(q)=4
 char *r = "abcde";//sizeof(r)=4
 char (*f)(void) = NULL;//sizeof(f)=4
 
char *s1[3] = {"aa","bb","cc"};
 //sizeof(s1)=12
 //sizeof(s1[0])=4
 //sizeof(*s1[0])=1
 
char *s2[3][3] = {{"aa","bb","cc"},{"aa","bb","cc"},{"aa","bb","cc"}};
 //sizeof(s2)=36
 //sizeof(s2[0])=12
 //sizeof(*s2[0])=4
 
char h[3][3] = {{1,2,3},{4,5,6},{7,8,9}};
 char (*ph)[3] = h;
 //sizeof(ph)=4
//sizeof(*ph)=3
 //sizeof(ph[0])=3
 //sizeof(*ph[0])=1

将C语言梳理一下，分布在以下10个章节中：

1. Linux-C成长之路（一）：Linux下C编程概要 http://www.linuxidc.com/Linux/2014-05/101242.htm
2. Linux-C成长之路（二）：基本数据类型 http://www.linuxidc.com/Linux/2014-05/101242p2.htm
3. Linux-C成长之路（三）：基本IO函数操作 http://www.linuxidc.com/Linux/2014-05/101242p3.htm
4. Linux-C成长之路（四）：运算符 http://www.linuxidc.com/Linux/2014-05/101242p4.htm
5. Linux-C成长之路（五）：控制流 http://www.linuxidc.com/Linux/2014-05/101242p5.htm
6. Linux-C成长之路（六）：函数要义 http://www.linuxidc.com/Linux/2014-05/101242p6.htm
7. Linux-C成长之路（七）：数组与指针 http://www.linuxidc.com/Linux/2014-05/101242p7.htm
8. Linux-C成长之路（八）：存储类，动态内存 http://www.linuxidc.com/Linux/2014-05/101242p8.htm
9. Linux-C成长之路（九）：复合数据类型 http://www.linuxidc.com/Linux/2014-05/101242p9.htm
10. Linux-C成长之路（十）：其他高级议题