String Handling Functions in C programming

 The library or built-in functions strlen(), strcpy(), strcat(), strcmp(), strrev() etc are used for string manipulation in C. These functions are defined in header file string.h. They are described in detail as follow.

              i.      strlen()

         This function returns the length of string. Its prototypes is as

int strlen(string s1);

example:

#include<string.h>                         void main()                           {                          char line[]="baba";                          int len;                          clrscr();                          len=strlen(line);                          printf("The length is %d",len);                          getch();                           }                          output:                          The length is 4

 

            ii.      strcpy()

   This function is used to copy one string to another. It is called as

   strcpy(destination_string, source_string);

        Thus, strcpy(s1,s2) means the content of s2 is copied to s1.

An example:

#include<string.h> void main()   {   char s1[]="adhikarib", s2[]="bindu";   clrscr();    strcpy(s1,s2);    printf("The string s1 is\t%s",s1);     getch();   } output:       The string s1 is   bindu

          iii.      strcat()

This function concatenates the source string at the end of the destination or target string. An example

#include<string.h> void main()   {   char s1[]="Bindu", s2[]="Adhikari";   clrscr();    strcat(s1,s2);    printf("The concated string is:\t%s",s1);     getch();   }      Output:        The concated string is: BinduAdhikari

           

          iv.       strcmp();

              This function compares two strings to find out whether they are same or different. The two strings are compared character by character until there is a mismatch or end of one of stings is reached. It two strings are equal, it returns zero, otherwise, it returns the difference between the ASCII values of the first non-matching pair of characters

 An example.

#include<string.h> void main()   {   char s1[]="bAa", s2[]="eaA";   int diff;   clrscr();   diff= strcmp(s1,s2);    printf("%d",diff);     getch();   } output:    -3

            v.      strrev();

This function is used to reverse all characters in a string except null character at the end of string. The reverse of string “abc” is “cba”.

#include<string.h> void main()   {   char s[]="cps";   clrscr();   strrev(s);    printf("%s",s);     getch();   }        Output:  spc