自己实现strcpy和strcat

strcpy的实现

# include<stdlib.h>
# include<stdio.h>
# include<assert.h>

char *MyStrcpy(char *dest, const char*src)
{
	assert(src != NULL&&dest != NULL);//断言
	char *p = dest;
	while (*dest++ = *src++);
	return p;
}

int main()
{
	char dest[20] = {0};
	const char *src = "world";
	MyStrcpy(dest,src);
	printf("%s\n", dest);
	system("pause");
	return 0;
}

strcat的实现

char *MyStrcat(char *dest, const char *src)
{
	char *p = dest;
	assert(dest!= NULL && src!= NULL);
	while (*dest != '\0')
	{
		dest++;
	}
	while (*dest++ = *src++);
	return p;	
}
int main()
{
	char dest[20] = "hello";
	char *src = " bit";
	//strcat(dest, src);
    MyStrcat(dest, src);
	printf("%s\n", dest);
	system("pause");
	return 0;
}