模拟实现 strcpy strcat strcmp strncpy strncat strncmp

最新推荐文章于 2023-03-10 21:52:26 发布

小矮多

最新推荐文章于 2023-03-10 21:52:26 发布

阅读量220

点赞数

CC 4.0 BY-SA版权

文章标签： C语言字符串函数

本文链接：https://blog.youkuaiyun.com/nefss_/article/details/94850732

题专栏收录该内容

21 篇文章

订阅专栏

本文详细介绍了如何模拟实现C语言中的字符串操作函数，包括strcpy、strcat、strcmp、strncpy、strncat和strncmp。通过自定义函数Mystrcpy、Mystrcat、Mystrcmp、Mystrncpy、Mystrncat和Mynstrncmp，文章提供了源代码示例，展示了如何进行字符串复制、连接和比较等操作。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

char * strcpy ( char * destination, const char * source );
char * strcat ( char * destination, const char * source );
int strcmp ( const char * str1, const char * str2 );

模拟实现：strcpy strcat strcmp

#include<stdio.h>
#include<Windows.h>

char *Mystrcpy(char *dest, const char *src)
{
	char *p = dest;
	while (*dest++ = *src++)
	return p;
}
char *Mystrcat(char *dest, const char*src)
{
	int *pc = dest;
	while (*dest != '\0')
	{
		dest++;
	}
	while (*dest++ = *src++)
	{
		;
	}
		return pc;
}
int Mystrcmp(const char *str1, const char *str2)
{
	while (*str1 == *str2)
	{
		str1++;
		str2++;
		if (*str1 == '\0')
		{
			return 0;
		}
	}
	if (*str1 > *str2)
	{
		return 1;
	}
	if (*str1 < *str2)
	{
		return -1;
	}
}
int main()
{
	char str1[20] = "abcd";
	char *str2 = "efgh";
	printf("str1=%s\n", Mystrcpy(str1, str2));
	printf("str1=%s\n", Mystrcat(str1, str2));
	printf("%d\n", Mystrcmp(str1, str2));
	system("pause");
	return 0;
}

str1=ebcd
str1=ebcdefgh
-1
请按任意键继续. . .

char * strncpy ( char * destination, const char * source, size_t num );
char * strncat ( char * destination, const char * source, size_t num );
int strncmp ( const char * str1, const char * str2, size_t num );

模拟实现：strncpy strncat strncmp

#include<stdio.h>
#include<Windows.h>

char *Mystrncpy(char *dest, const char* src, int count)
{
	int i = 0;
	char *p = dest;
	while (i < count)
	{
		*dest++=*src++;
		i++;
	}
	return p;
}
char *Mystrncat(char *dest, const char *src, int count)
{
	int i = 0;
	char *pc = dest;
	while (*dest != '\0')
	{
		*dest++;
	}
	for (i = 0; i < count; i++)
	{
		*dest++ = *src++;
	}
	return pc;
}
int Mystrncmp(const char*str1, const char*str2, int count)
{
	int i = 0;
	int differ = 0;
	while (i < count && ((differ = *str1 - *str2) == 0 )&& *str1 != '\0')
	{
		i++;
		str1++;
		str2++;
	}
	return differ;
}
int main()
{
	char str1[20] = "abcd";
	char *str2 = "efgh";
	printf("str1=%s\n", Mystrncpy(str1, str2, 2));
	printf("str1=%s\n", Mystrncat(str1, str2, 2));
	printf("%d\n", Mystrncmp(str1, str2, 2));
	system("pause");
	return 0;
}

str1=efcd
str1=efcdef
0
请按任意键继续. . .