自己设计实现strlen,strcat,strcpy,strcmp。
int my_strlen(char *a)
{
int count=0;
while(*a)
{
a++;
count++;
}
return count;
}
char* my_strcat(char *a,char *b)
{
char *c;
c=a;
while(*a)
{
a++;
}
while(*b)
{
*a++=*b++;
}
return c;
}
char* my_strcpy(char *c,char *b)
{
char *d;
d=c;
while(*b)
{
*c++=*b++;
}
return d;
}
int my_strcmp(char* a,char* b)
{
while((*a!=0)&&(*b!=0))
{
a++;
b++;
}
if(*a==0)
return -1;
else if(*b==0)
return 1;
else
return 0;
}
int main()
{
int strlen,strcmp;
char *p1,*p2;
char arr1[20]="lalalalala";
char arr2[]=" huhuhu";
char arr3[20]="0";
strlen=my_strlen(arr1);
printf("%d\n",strlen);
p1=my_strcat(arr1,arr2);
while(*p1)
{
printf("%c",*p1++);
}
printf("\n");
p2=my_strcpy(arr3,arr2);
while(*p2)
{
printf("%c",*p2++);
}
printf("\n");
strcmp=my_strcmp(arr1,arr2);
printf("%d\n",strcmp);
return 0;
}本文出自 “sunshine225” 博客，请务必保留此出处http://10707460.blog.51cto.com/10697460/1754038
strlen,strcat,strcpy,strcmp的实现
原文：http://10707460.blog.51cto.com/10697460/1754038