彻底掌握C语言strcat函数的用法_C 语言

char* __cdecl strcat (char * dst, const char * src);

int main()
{
	char ch1[20] = "Hello";
	char ch2[] = "World";
	strcat(ch1, ch2);
	printf("%s\n", ch1);
	return 0;
}

char * __cdecl strcat (char * dst, const char * src)//__cdecl：是函数调用约定
{
	char * cp = dst;
	while( *cp )
	cp++;                 //find end of dst 
	while((*cp++ = *src++) != '\0') ;       //Copy src to end of dst 
	return( dst );                  //return dst 
}

char* my_strcat(char* str1, const char* str2)
{
	char* first = str1;
	assert(str1 && str2);
	//目标空间的'\0'
	while (*str1 != '\0')
	{
		str1++;
	}
	//追加内容到目标空间
	while (*str1++ = *str2++)
	{
		;
	}
	return first;
}
int main()
{
	char ch1[20] = "Hello";
	char ch2[] = "World";
	printf("%s\n", my_strcat(ch1, ch2));//这里包含链式访问
	return 0;
}