#define _CRT_SECURE_NO_WARNINGS
#include<stdlib.h>
#include<string.h>
#include<stdio.h>
void main()
{
char a[] = "i am a student"; //默认 结尾,为字符串(字符数组表示)
char b[64];
printf("strlen(a)=%d,sizeof(a)=%d
", strlen(a), sizeof(a)); //str为字符串长度14 sizeof为数组长度15,包括
int i = 0;
for (i = 0; *(a + i) != ' '; i++) // a[i] = *(a+i) a代表数组首地址,i步长为1
{
*(b + i) = *(a + i);
}
*(b + i) = ' '; //若不将最后一位设置为 ,则表示单纯的字符数组,不是字符串,不能用%s输出
printf("a:%s
", a);
printf("b:%s
", b);
system("pause");
return ;
}

void copystr(char * from,char * to) //拷贝字符串函数
{
int i;
//1.
//for (i = 0; *(from + i) != ' '; i++)
//{
// //to[i] = from[i]; //to[i] 和 *(to+i)一样
// *(to + i) = *(from + i);
//}
//*(to + i) = ' ';
//2.
//for (; *from != ' ';)
//{
// *to++ = *from++; //*to=*from to++;from++
//}
//*to = ' ';
//3
//while ((*to = *from) != ' ')
//{
// to++;
// from++;
//}
while ((*to++ = *from++) != ' ')
{
}
return;
}
void main()
{
char from[] = "i am a student"; //提前给from 和 to 分配内存
char to[64];
copystr(from, to);
printf("%s
",to);
system("pause");
return;
}