The strlen() function is defined in the string.h header file. It helps to calculate the length of a given string without including the terminating null character.
size_t strlen(const char *str); #where str should be a string
The strlen() function takes a single parameter. While computing it doesn't count the null character \0.
Parameter | Description | Required / Optional |
---|---|---|
str | the string whose length is to be found | Required |
The function returns the length of the string in a type size_t (the unsigned integer type).
Input | Return Value |
---|---|
string | length of string(integer) |
#include <stdio.h>
#include <string.h>
int main()
{
char string[30];
int length;
strcpy(string, "learnetutorials.com");
length = strlen(string);
printf("The length of |%s| is |%d|\n", string, length);
return(0);
}
Output:
The length of tutorialspoint.com| is |18|
#include <stdio.h>
#include <string.h>
int main (){
char x[30]="Tutorials";
char y[30]={'T','u','t','o','r','i','a','l','s','\0'};
// using the %zu format specifier to print size_t
printf("Length of string x = %zu \n",strlen(x));
printf("Length of string y = %zu \n",strlen(y));
return 0;
}
Output:
Length of string x = 9 Length of string y = 9