Strings in C


1.What is Strings in C ?

Ans : A String in C programming is a sequence of characters terminated with a null character ‘\0’. The C String is stored as an array of characters. The difference between a character array and a C string is that the string in C is terminated with a unique character ‘\0’.

1. String Deceleration

Syntax : char str_name[size];

Example : char str_name[10]

2. Initialization of string 

Syntax : char str_name[size]={elements of string separated}

Example : char str[7]={'A','V','E','N','G','E','R'} or char str [7]="AVENGERS"

Functions of String : There are total 7 functions in string.

1. strlen : This function is used to determine the length of a string. 

Syntax : strlen(str_name);

Note : The length of the string will be in int form.

Example :

#include<stdio.h>

#include<string.h>

int main ()

{

char a[]="sanskar";

strlen(a); //function of string

printf("The length of the name is %d",strlen(a));

}

Output :



2.strupr :  This function is used to convert the lowercase sentence to upper case.

Example :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="sanskar";
strupr(a); //function of string
printf("The name or sentence convrted into uppercase %s ",strupr(a));
}

Output :



3. strlwr : This function is used to convert the uppercase sentence to lowercase.

Example :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="SANSKAR";
strlwr(a); //function of string
printf("The name converted into lowercase is %s",a);
}

Output :



4. strrev : This function is used to reverse the sentence or a name.

Example :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="sanskar";
strrev(a);  //function of string
printf("The Name return in reverse is %s",a);
}

Output :



5. strcmp : This function is used to compare two strings.

Note : When we compare two strings we get value in integer. If the two stings are equal the output will be 0.If the strings are not equal the output will be -1 and if both the strings are same but one is lowercase and one is in uppercase we will get output 1.

Example :

a. When strings are Equal :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="SANSKAR";
char b[]="SANSKAR";
strcmp(a,b);  //function of string
printf("%d",strcmp(a,b));
}
 
Output :



b. When strings are Not Equal :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="sanskar";
char b[]="suraj";
strcmp(a,b);  //function of string
printf("%d",strcmp(a,b));
}

Output :




c. When both the strings are equal but one is in uppercase and lowercase.

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="sanskar";
char b[]="SANSKAR";
strcmp(a,b);  //function of string
printf("%d",strcmp(a,b));
}

Output :



6. strcat : This function is used to to conjoin (concatenation) two stings.

Example :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="Snow";
char b[]="ball";
strcat(a,b);  //funtion of string
printf("%s",a);
}

Output :



7. strcpy : This function is used to copy one string to another string.

Example :

#include<stdio.h>
#include<string.h>
int main ()
{
char a[]="suraj";
char b[]="Sanskar";
strcpy(a,b);  //funtion of string
printf("%s",a);
}

Output :