当前位置

首页 > 商务英语 > 计算机英语 > c语言的用法总结

c语言的用法总结

推荐人: 来源: 阅读: 3.92K 次
c语言的用法总结
随着经济的迅速发展以及科学技术水平的不断提高,计算机技术发展迅速,成为21世纪的热门技术,在很大程度上促进生产力水平的提高以及经济的发展。C语言的发展还在进行着,并且不断趋于完善,它具有较多的优点。下面小编就为大家分享下c语言的用法总结。  c语言的用法总结1  函数名: stpcpy  功 能: 拷贝一个字符串到另一个  用 法: char *stpcpy(char *destin, char *source);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char string[10];  char *str1 = "abcdefghi";  stpcpy(string, str1);  printf("%sn", string);  return 0;  }  c语言的用法总结2  函数名: strcat  功 能: 字符串拼接函数  用 法: char *strcat(char *destin, char *source);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char destination[25];  char *blank = " ", *c = "C++", *Borland = "Borland";  strcpy(destination, Borland);  strcat(destination, blank);  strcat(destination, c);  printf("%sn", destination);  return 0;  }  c语言的用法总结3  函数名: strchr  功 能: 在一个串中查找给定字符的第一个匹配之处  用 法: char *strchr(char *str, char c);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char string[15];  char *ptr, c = 'r';  strcpy(string, "This is a string");  ptr = strchr(string, c);  if (ptr)  printf("The character %c is at position: %dn", c, ptr-string);  else  printf("The character was not foundn");  return 0;  }  c语言的用法总结4  函数名: strcmp  功 能: 串比较  用 法: int strcmp(char *str1, char *str2);  看Asic码,str1>str2,返回值 > 0;两串相等,返回0  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "aaa", *buf2 = "bbb", *buf3 = "ccc";  int ptr;  ptr = strcmp(buf2, buf1);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  else  printf("buffer 2 is less than buffer 1n");  ptr = strcmp(buf2, buf3);  if (ptr > 0)  printf("buffer 2 is greater than buffer 3n");  else  printf("buffer 2 is less than buffer 3n");  return 0;  }  c语言的用法总结5  函数名: strncmpi  功 能: 将一个串中的一部分与另一个串比较, 不管大小写  用 法: int strncmpi(char *str1, char *str2, unsigned maxlen);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "BBB", *buf2 = "bbb";  int ptr;  ptr = strcmpi(buf2, buf1);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  if (ptr < 0)  printf("buffer 2 is less than buffer 1n");  if (ptr == 0)  printf("buffer 2 equals buffer 1n");  return 0;  }  c语言的用法总结6  函数名: strcpy  功 能: 串拷贝  用 法: char *strcpy(char *str1, char *str2);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char string[10];  char *str1 = "abcdefghi";  strcpy(string, str1);  printf("%sn", string);  return 0;  }  c语言的用法总结7  函数名: strcspn  功 能: 在串中查找第一个给定字符集内容的段  用 法: int strcspn(char *str1, char *str2);  程序例:  #include <stdio.h>  #include <string.h>  #include <alloc.h>  int main(void)  {  char *string1 = "1234567890";  char *string2 = "747DC8";  int length;  length = strcspn(string1, string2);  printf("Character where strings intersect is at position %dn", length);  return 0;  }  c语言的用法总结8  函数名: strdup  功 能: 将串拷贝到新建的位置处  用 法: char *strdup(char *str);  程序例:  #include <stdio.h>  #include <string.h>  #include <alloc.h>  int main(void)  {  char *dup_str, *string = "abcde";  dup_str = strdup(string);  printf("%sn", dup_str);  free(dup_str);  return 0;  }  c语言的用法总结9  函数名: stricmp  功 能: 以大小写不敏感方式比较两个串  用 法: int stricmp(char *str1, char *str2);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "BBB", *buf2 = "bbb";  int ptr;  ptr = stricmp(buf2, buf1);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  if (ptr < 0)  printf("buffer 2 is less than buffer 1n");  if (ptr == 0)  printf("buffer 2 equals buffer 1n");  return 0;  }  c语言的用法总结10  函数名: strerror  功 能: 返回指向错误信息字符串的指针  用 法: char *strerror(int errnum);  程序例:  #include <stdio.h>  #include <errno.h>  int main(void)  {  char *buffer;  buffer = strerror(errno);  printf("Error: %sn", buffer);  return 0;  }  c语言的用法总结11  函数名: strcmpi  功 能: 将一个串与另一个比较, 不管大小写  用 法: int strcmpi(char *str1, char *str2);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "BBB", *buf2 = "bbb";  int ptr;  ptr = strcmpi(buf2, buf1);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  if (ptr < 0)  printf("buffer 2 is less than buffer 1n");  if (ptr == 0)  printf("buffer 2 equals buffer 1n");  return 0;  }  c语言的用法总结12  函数名: strncmp  功 能: 串比较  用 法: int strncmp(char *str1, char *str2, int maxlen);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "aaabbb", *buf2 = "bbbccc", *buf3 = "ccc";  int ptr;  ptr = strncmp(buf2,buf1,3);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  else  printf("buffer 2 is less than buffer 1n");  ptr = strncmp(buf2,buf3,3);  if (ptr > 0)  printf("buffer 2 is greater than buffer 3n");  else  printf("buffer 2 is less than buffer 3n");  return(0);  }  c语言的用法总结13  函数名: strncmpi  功 能: 把串中的一部分与另一串中的一部分比较, 不管大小写  用 法: int strncmpi(char *str1, char *str2);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "BBBccc", *buf2 = "bbbccc";  int ptr;  ptr = strncmpi(buf2,buf1,3);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  if (ptr < 0)  printf("buffer 2 is less than buffer 1n");  if (ptr == 0)  printf("buffer 2 equals buffer 1n");  return 0;  }  c语言的用法总结14  函数名: strncpy  功 能: 串拷贝  用 法: char *strncpy(char *destin, char *source, int maxlen);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char string[10];  char *str1 = "abcdefghi";  strncpy(string, str1, 3);  string[3] = '';  printf("%sn", string);  return 0;  }  c语言的用法总结15  函数名: strnicmp  功 能: 不注重大小写地比较两个串  用 法: int strnicmp(char *str1, char *str2, unsigned maxlen);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *buf1 = "BBBccc", *buf2 = "bbbccc";  int ptr;  ptr = strnicmp(buf2, buf1, 3);  if (ptr > 0)  printf("buffer 2 is greater than buffer 1n");  if (ptr < 0)  printf("buffer 2 is less than buffer 1n");  if (ptr == 0)  printf("buffer 2 equals buffer 1n");  return 0;  }  c语言的用法总结16  函数名: strnset  功 能: 将一个串中的所有字符都设为指定字符  用 法: char *strnset(char *str, char ch, unsigned n);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char *string = "abcdefghijklmnopqrstuvwxyz";  char letter = 'x';  printf("string before strnset: %sn", string);  strnset(string, letter, 13);  printf("string after strnset: %sn", string);  return 0;  }  c语言的用法总结17  函数名: strpbrk  功 能: 在串中查找给定字符集中的字符  用 法: char *strpbrk(char *str1, char *str2);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char *string1 = "abcdefghijklmnopqrstuvwxyz";  char *string2 = "onm";  char *ptr;  ptr = strpbrk(string1, string2);  if (ptr)  printf("strpbrk found first character: %cn", *ptr);  else  printf("strpbrk didn't find character in setn");  return 0;  }  c语言的用法总结18  函数名: strrchr  功 能: 在串中查找指定字符的最后一个出现  用 法: char *strrchr(char *str, char c);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char string[15];  char *ptr, c = 'r';  strcpy(string, "This is a string");  ptr = strrchr(string, c);  if (ptr)  printf("The character %c is at position: %dn", c, ptr-string);  else  printf("The character was not foundn");  return 0;  }  c语言的用法总结19  函数名: strrev  功 能: 串倒转  用 法: char *strrev(char *str);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char *forward = "string";  printf("Before strrev(): %sn", forward);  strrev(forward);  printf("After strrev(): %sn", forward);  return 0;  }  c语言的用法总结20  函数名: strset  功 能: 将一个串中的所有字符都设为指定字符  用 法: char *strset(char *str, char c);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char string[10] = "123456789";  char symbol = 'c';  printf("Before strset(): %sn", string);  strset(string, symbol);  printf("After strset(): %sn", string);  return 0;  }  c语言的用法总结21  函数名: strspn  功 能: 在串中查找指定字符集的子集的第一次出现  用 法: int strspn(char *str1, char *str2);  程序例:  #include <stdio.h>  #include <string.h>  #include <alloc.h>  int main(void)  {  char *string1 = "1234567890";  char *string2 = "123DC8";  int length;  length = strspn(string1, string2);  printf("Character where strings differ is at position %dn", length);  return 0;  }  c语言的用法总结22  函数名: strstr  功 能: 在串中查找指定字符串的第一次出现  用 法: char *strstr(char *str1, char *str2);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char *str1 = "Borland International", *str2 = "nation", *ptr;  ptr = strstr(str1, str2);  printf("The substring is: %sn", ptr);  return 0;  }  c语言的用法总结23  函数名: strtod  功 能: 将字符串转换为double型值  用 法: double strtod(char *str, char **endptr);  程序例:  #include <stdio.h>  #include <stdlib.h>  int main(void)  {  char input[80], *endptr;  double value;  printf("Enter a floating point number:");  gets(input);  value = strtod(input, &endptr);  printf("The string is %s the number is %lfn", input, value);  return 0;  }  c语言的用法总结24  函数名: strtok  功 能: 查找由在第二个串中指定的分界符分隔开的单词  用 法: char *strtok(char *str1, char *str2);  程序例:  #include <string.h>  #include <stdio.h>  int main(void)  {  char input[16] = "abc,d";  char *p;  /* strtok places a NULL terminator  in front of the token, if found */  p = strtok(input, ",");  if (p) printf("%sn", p);  /* A second call to strtok using a NULL  as the first parameter returns a pointer  to the character following the token */  p = strtok(NULL, ",");  if (p) printf("%sn", p);  return 0;  }  c语言的用法总结25  函数名: strtol  功 能: 将串转换为长整数  用 法: long strtol(char *str, char **endptr, int base);  程序例:  #include <stdlib.h>  #include <stdio.h>  int main(void)  {  char *string = "87654321", *endptr;  long lnumber;  /* strtol converts string to long integer */  lnumber = strtol(string, &endptr, 10);  printf("string = %s long = %ldn", string, lnumber);  return 0;  }  函数名: strupr  功 能: 将串中的小写字母转换为大写字母  用 法: char *strupr(char *str);  程序例:  #include <stdio.h>  #include <string.h>  int main(void)  {  char *string = "abcdefghijklmnopqrstuvwxyz", *ptr;  /* converts string to upper case characters */  ptr = strupr(string);  printf("%sn", ptr);  return 0;  }  c语言的用法总结26  函数名: swab  功 能: 交换字节  用 法: void swab (char *from, char *to, int nbytes);  程序例:  #include <stdlib.h>  #include <stdio.h>  #include <string.h>  char source[15] = "rFna koBlrna d";  char target[15];  int main(void)  {  swab(source, target, strlen(source));  printf("This is target: %sn", target);  return 0;  }