[C language] string & string processing function

string

  • A string of length n, where n+1 bits are\0
char site[7] = {'T','i','a','n','J','i','n'};
char site[] = 'Tianjin';
printf("%s", site);

function

#include<stdio.h>
#include<string.h>

strcpy(str1,str2);  //  复制str2到str1
strcat(str1,str2);  //  连接str2到str1
strlen(str1);       //  返回str1长度
strcmp(str1,str2);  //  值相等返回0, 大于返回1, 小于返回-1
strchr(str1,ch);    //  返回指针, 指向字符ch首次出现的位置
strstr(str1,st);    //  返回指针, 指向字符串st首次出现的位置

character position strchr()

char *pr1 = "Tian";
char pr2 = 'a';
char *pt = strchr(pr1,pr2);
printf("%c",*pt);

output a, of typechar*

String position strstr()

char *pr1 = "Tian";
char *pr2 = "ian";
char *pt = strstr(pr1,pr2);
printf("%c",*pt);

output i, of typechar*

input Output

standard document

The C language treats all devices as files, devices are handled in the same way as files, the following files are automatically opened during program execution to access the keyboard & screen.

standard document file pointer equipment
standard input stdin keyboard
stdout stdout Screen
standard error stderr your screen
stdio.h: standard input and output files

enter

  • getchar(): read the next available character from the screen, returning an integer
    • int getchar(void)
  • gets(): Read a line from stdin to the buffer pointed to by s, until a terminator /EOF
    • char *gets(char *s)
  • scanf(): Read input from the standard input stream stdin, browse the input according to the provided format
    • int scanf(const char *formate, ...)

output

  • putchar(): output characters to the screen, return the same character, output only a single character at the same time
    • int putchar(int c)
  • puts(): write the string s and a trailing newline to stdout
    • int puts(const char *s)
  • printf(): The output is written to the standard output stream stdout, and the output is generated by the format
    • int printf(const char *format)
    scanf("%s %d",str,&sst);
    

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Origin blog.csdn.net/weixin_46143152/article/details/126672035