// lengthCString2B.cpp
// Finds the length of a C-string
// using a while loop.
// The C-string is a line of text
// and may contain whitespace.

#include <iostream>
using namespace std;

int main()
{
   // Announce purpose of program:
   cout << "This program finds the length of a C-string "
             << "entered by the user." << endl << endl;

   // Input a C-string:
   cout << "Enter a line no more than 20 characters long:> ";
   char line[21];    // 20 characters plus the null character
   cin.getline(line, 21);   // Reads a line of text,
                            // including whitespace

   // If the user pressed [Enter] without entering
   // any characters, line will be an empty string.

   // Compute the length of the entered C-string
   // by searching for the null character:

   // Prepare to search for a null character at the
   // first possible location in line:
   int length = 0;

   // Check each consecutive location in line
   // until a null character is found:
   while ( line[length] != '\0' )
      length = length + 1;

   // Output the entered C-string and its length:
   cout << "You typed: " << line << endl;
   cout << "This line contains " << length << " characters." << endl;

   return 0;
}  // function main