免费p2p网站建设,太原定制网站建设制作公司,wordpress 如何维护,如何做exo网站CSDN的各位友友们你们好,今天千泽为大家带来的是C语言中字符函数和字符串函数的详解,掌握了这些内容能够让我们更加灵活的运用字符串,接下来让我们一起走进今天的内容吧!写这篇文章需要在cplusplus.com上大量截图,十分不易!如果对您有帮助的话希望能够得到您的支持和帮助,我会持…CSDN的各位友友们你们好,今天千泽为大家带来的是C语言中字符函数和字符串函数的详解,掌握了这些内容能够让我们更加灵活的运用字符串,接下来让我们一起走进今天的内容吧!写这篇文章需要在cplusplus.com上大量截图,十分不易!如果对您有帮助的话希望能够得到您的支持和帮助,我会持续更新的!0.前言C语言中对字符和字符串的处理很是频繁但是C语言本身是没有字符串类型的字符串通常放在常量字符串中或者字符数组中。字符串常量适用于那些对它不做修改的字符串函数.首先,我们将本次要介绍的函数分一下类长度不受限制的字符串函数 strcpy strcat strcmp长度受限制的字符串函数介绍 strncpy strncat strncmp1.函数介绍strcpy例子/* strcpy example */
#include stdio.h
#include string.hint main ()
{char str1[]Sample string;char str2[40];char str3[40];strcpy (str2,str1);strcpy (str3,copy successful);printf (str1: %s\nstr2: %s\nstr3: %s\n,str1,str2,str3);return 0;
}输出str1: Sample stringstr2: Sample stringstr3: copy successful模拟实现strcpy#includestdio.h
#includestring.h
//1.参数顺序
//2.函数的功能停止条件
//3.assert
//4.const修饰指针
//5.函数返回值
//6.题目出自《高质量C/C编程》书籍最后的试题部分
//返回的是目标空间的起始地址
#includeassert.h
char * my_strcpy(char * dest, const char* src)
{char * ret dest;assert(dest!NULL);assert(src ! NULL);while ((*dest *src)){;}return ret;
}
int main()
{char arr1[] hehe;char arr2[20] { 0 };my_strcpy(arr2, arr1);printf(%s\n, arr2);return 0;
}友友们记得动手实践!!!strcat官方例子/* strcat example */
#include stdio.h
#include string.hint main ()
{char str[80];strcpy (str,these );strcat (str,strings );strcat (str,are );strcat (str,concatenated.);puts (str);return 0;
}输出 these strings are concatenated. 模拟实现strcat#includestdio.h
#includeassert.h
char* my_strcat(char* dest, const char* src)
{char* ret dest;assert(dest ! NULL);assert(src ! NULL);//找目标空间的\0while (*dest!\0){dest;}//拷贝while ((*dest *src)){;}return ret;
}
int main()
{char arr1[20] hello ;char arr2[] world;//追加my_strcat(arr1, arr2);printf(%s\n, arr1);return 0;
}strcmp官方例子#include stdio.h
#include string.hint main ()
{char key[] apple;char buffer[80];do {printf (Guess my favorite fruit? );fflush (stdout);scanf (%79s,buffer);} while (strcmp (key,buffer) ! 0);puts (Correct answer!);return 0;
}输出Guess my favourite fruit? orangeGuess my favourite fruit? appleCorrect answer!模拟实现strcmp#includestdio.h
#includestring.h
#includeassert.h
int my_strcmp(const char* str1, const char* str2)
{assert(str1 ! NULL);assert(str2 ! NULL);while (*str1 *str2){if (*str1 \0){return 0;}str1;str2;}if (*str1 *str2){return 1;}else{return -1;}
}int main()
{char arr1[] abcdef;char arr2[] bbcdef;int ret my_strcmp(arr1, arr2);printf(%d\n, ret);return 0;
}strncpy官方例子/* strncpy example */
#include stdio.h
#include string.hint main ()
{char str1[] To be or not to be;char str2[40];char str3[40];/* copy to sized buffer (overflow safe): */strncpy ( str2, str1, sizeof(str2) );/* partial copy (only 5 chars): */strncpy ( str3, str2, 5 );str3[5] \0; /* null character manually added */puts (str1);puts (str2);puts (str3);return 0;
}输出To be or not to be To be or not to be To be模拟实现strncpy#includestdio.h
#includestring.h
#includeassert.h
int main()
{char arr1[] abcdef;char arr2[5] { 0 };strncpy(arr2, arr1, 3);printf(%s\n, arr2);return 0;
}strncat官方例子/* strncat example */
#include stdio.h
#include string.hint main ()
{char str1[20];char str2[20];strcpy (str1,To be );strcpy (str2,or not to be);strncat (str1, str2, 6);puts (str1);return 0;
}输出To be or not模拟实现strncat#includestdio.h
#includestring.h
#includeassert.h
int main()
{char arr1[20] hello \0xxxxxxxx;char arr2[] world;strncat(arr1, arr2, 3);printf(%s\n, arr1);return 0;
}strncmp官方例子/* strncmp example */
#include stdio.h
#include string.hint main ()
{char str[][5] { R2D2 , C3PO , R2A6 };int n;puts (Looking for R2 astromech droids...);for (n0 ; n3 ; n)if (strncmp (str[n],R2xx,2) 0){printf (found %s\n,str[n]);}return 0;
}输出Looking for R2 astromech droids... found R2D2 found R2A6模拟实现strncmp#includestdio.h
#includestring.h
#includeassert.h
int main()
{char arr1[] abcdef;char arr2[] abcq;int ret strncmp(arr1, arr2, 4);printf(%d\n, ret);return 0;
}好了,今天的分享暂时告一段落,预知后续请看下篇,祝大家学习进步!
