String library function
There are several string library functions used to manipulate string and the
prototypes for these functions are in header file “string.h”. Several string functions
are
strlen()
This function return the length of the string. i.e. the number of characters in the
string excluding the terminating NULL character.
It accepts a single argument which is pointer to the first character of the string.
For example
strlen(“suresh”);
It return the value 6.
In array version to calculate legnth:
int str(char str[])
{
int i=0;
while(str[i]!=’\o’)
{
i++;
}
return i;
}
Example:
#include
#include
void main()
{
char str[50];
print(”Enter a string:”);
gets(str);
printf(“Length of the string is %d\n”,strlen(str));
}
Output:
Enter a string: C in Depth
Length of the string is 8
strcmp()
This function is used to compare two strings. If the two string match, strcmp()
return a value 0 otherwise it return a non-zero value. It compare the strings
character by character and the comparison stops when the end of the string is
reached or the corresponding characters in the two string are not same.
strcmp(s1,s2)
return a value:
<0 when s1<s2
=0 when s1=s2
>0 when s1>s2
The exact value returned in case of dissimilar strings is not defined. We only know
that if s1s2 then a positive
value will be returned.
For example:
/*String comparison…………………….*/
#include
#include
void main()
{
char str1[10],str2[10];
printf(“Enter two strings:”);
gets(str1);
gets(str2);
if(strcmp(str1,str2)==0)
{
printf(“String are same\n”);
}
else
{
printf(“String are not same\n”);
}
}
Output
Enter two strings
Cat
Dog
String are same
