Tutorials

It is a sequence of character enclose in double quotes are called as string.

Declaring string

char str[20] =”saplogic”;

Char str[20] ={‘s’,’a’,’p’,’l’,’o’,’g’,’i’,’c’,’\0’};

String handling function
1 strlen()
2 strcpy()
3 strcat()
4 strcmp()
5 strupr()
6 strlwr()
7 strrev()
All are present in #include file

By using strlen() function we find the length of character.

EX: WAP to calculate length of string

#include 
#include 
int main(){
    char a[20]="Ashish";
    char b[20]={'A','s','h','i','s','h','\0'};
    char c[20];
    printf("Enter string: ");
    gets(c);  
    printf("Length of string a=%d \n",strlen(a));
    //calculates length of string before null charcter
    printf("Length of string b=%d \n",strlen(b));   
    printf("Length of string c=%d \n",strlen(c));
    getch(); 
   return 0;
}

Ex:WAP to find length without string library function

#include<stdio.h>
#include<conio.h>
void mystrlen(char *);
main()
{
 char str1[20];
 clrscr();
 printf("\n Enter Any String : ");
 gets(str1);
 mystrlen(str1);
 getch();
 }
 void mystrlen(char *s1)
 {
  int length=0;
  while(*s1!='\0')
  {
   length++;
   s1++;
  }
   printf("Length is %d ",length);
}

o/p

Length is 4

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By using strcpy() function we copy one string from one location to another locatrion.

Ex: WAP for copy string from one location to another location

#include 
#include 
#include 
int main(){
    char a[10],b[10];
    printf("Enter string: ");
    gets(a);
    strcpy(b,a);   // String a is copied to string b.
    printf("Copied string is : ");
    puts(b);
    getch();
    return 0;
}

WAP to copy string without string function

#include<stdio.h>
#include<conio.h>
void mystrcpy(char *,char *);
main()
{
 char str1[20],str2[20];
 clrscr();
 printf("\n Enter Any String : ");
 gets(str1);
 mystrcpy(str1,str2);
 printf("After Copied  ");
 puts(str2);
 getch();
 }
 void mystrcpy(char *s1,char *s2)
 {
  while(*s1!='\0')
  {
   *s2=*s1;
   s1++;s2++;
  }
  *s2='\0';
 }

o/p

Enter any string: prashant
After copied
Prashant

---

By using string concatenation strcat() function we concatenate two string that is we add two string.

Ex: WAP to concat two string

#include 
#include 
#include 
int main(){
    char str1[]="This is ", str2[]="help4code.com";
    strcat(str1,str2);  
    puts(str1);    
    puts(str2); 
    getch();
    return 0;
}

WAP to concate two strings without string function

#include<stdio.h>
#include<conio.h>
void mystrcat(char *,char *);
main()
{
 char str1[20],str2[20];
 clrscr();
 printf("\n Enter First String : ");
 gets(str1);
 printf("\n Enter Second String : ");
 gets(str2);
 mystrcat(str1,str2);
 printf("After concatenation  ");
 puts(str1);
 getch();
 }
 void mystrcat(char *s1,char *s2)
 {
  while(*s1!='\0')
  {
   s1++;
  }
  while(*s2!='\0')
  {
   *s1=*s2;
   s1++;s2++;
  }
  *s1='\0';
 }

o/p

Enter First String : prashant
Enter Second String:jha
After concatenation
Prashantjha

---

By using strcmp() string comparison function we compare two string.

Ex: WAP for string comparision

#include <stdio.h>
#include <string.h>
#include <conio.h>
int main(){
 char str1[20],str2[20];
  printf("Enter first string: ");
  gets(str1);
  printf("Enter second string: ");
  gets(str2);
  if(strcmp(str1,str2)==0)
      printf("\nBoth strings are equal");
  else
      printf("\nStrings are not equal");
    getch(); 
   return 0;
}

WAP to compare string without string function

#include<stdio.h>
#include<conio.h>
void mystrcmp(char *,char *);
main()
{
 char str1[20],str2[20];
 clrscr();
 printf("\n Enter First String : ");
 gets(str1);
 printf("\n Enter Second String : ");
 gets(str2);
 mystrcmp(str1,str2);
 getch();
 }
 void mystrcmp(char *s1,char *s2)
 {
  int flag=1;
  while(*s1!='\0' || *s2!='\0')
  {
   if(*s1!=*s2)
      flag=0;
   s1++;s2++;
  }
   if(flag==1)
      puts("\n Strings are matched");
   else
      puts("\n Strings are not matched");
}

o/p

Enter First String :jha
Enter Second String :jha
Strings are matched

---

It is a string upper case function By using it we can convert lower case character to upper case character.

Ex: WAP to convert lower case to upper case

#include <stdio.h>
#include <string.h>
#include <conio.h>
int main(){
    char str1[]="Ashish Gadpayle";
    puts(strupr(str1)); 
    getch(); 
   return 0;
}

WAP to convert string into uppercase without string function

#include<stdio.h>
#include<conio.h>
void mystrupr(char *s);
main()
{
 char ch[20];
 clrscr();
 printf("\n Enter any String : ");
 gets(ch);
 mystrupr(ch);
 printf("\n Upper case String is ");
 puts(ch);
 getch();
 }
 void mystrupr(char *s)
 {
  while(*s!='\0')
  {
   *s=*s-32;
   s++;
  }

 }  

o/p

Enter any String : SSS
Upper case String is:333

---

It is a string lower case function

Ex: WAP for lower case function

#include <stdio.h>
#include <string.h>
#include <conio.h>
int main(){
    char str1[]="ASHISH GADPAYLE";
    puts(strlwr(str1)); 
    getch(); 
   return 0;
}

WAP to convert string into lowercase without string function

#include<stdio.h>
#include<conio.h>
void mystrlwr(char *s);
main()
{
 char ch[20];
 clrscr();
 printf("\n Enter any String : ");
 gets(ch);
 mystrlwr(ch);
 printf("\n Upper case String is ");
 puts(ch);
 getch();
 }
 void mystrlwr(char *s)
 {
  while(*s!='\0')
  {
   *s=*s+32;
   s++;
  }
 }

o/p

Enter any String : SSS
Upper case String is:sss

---

It is a string reverse function By using it we can reverse the function.

Ex: WAP for reverse string

#include<stdio.h>
#include<conio.h>
main()
{
 char str1[20],rev[20];
 int n,i=0,j;
 clrscr();
 printf("\n Enter any String : ");
 gets(str1);
 n=strlen(str1);
 j=n-1;
  while( i>=0 && i

Output

Enter any String : jha
Reverse String is: ahj

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