字符串之_strncat

功能：将src的前n个字符添加到dest的后面

输入:dest,src,count

返回：ret

#include <iostream>

#include <assert.h>

using namespace std;

char * _strncat(char *dest,const char *src,int count)

{

	assert((dest != NULL)&&(src != NULL));

	char *ret = dest;

	while(*dest != '\0') dest++;

	while (count--)

	{

		if (!(*dest++ = *src++))

		{

			return ret;

		}

	}

	*dest = '\0';

	return ret;

}

int main()

{

	 char str1[20] = "abcdef";

	 char str2[20] = "hello world";

	cout << _strncat(str1,str2,3)<<endl;

	return 0;

};