Introduction to Programming (CS201) - Function Length of string up to 256 character

// This program is calling a function to calculate the length of any String up to 256 charachter.
#include <iostream>

using namespace std;

//Function declaration
int sLength ( int );

main( )
{

int c;
cout<<"Enter any string: ";
    cout << "\n No. of digits in given number is: " << sLength(c);
}



// function to calculate the length of string

int sLength ( int str )
{ 
int i,count=0;
   
char ch[256];
    gets(ch);
   
    for(i=0;ch[i]!='\0';i++)
    {
    count++;
    }
    return count;
}