// File: mystring.cpp
// ==================
// Implementation file for user-defined String class that stores
// characters internally in a fixed size array.

#include <iostream.h>
#include <string.h>  // for strlen(), etc.
#include "mystring.h"

String::String()
{
  contents[0] = '\0';
  len = 0;
}

void String::assign(const char s[])
{
  strcpy(contents, s);
  len = strlen(s);
}

void String::append(const String &str)
{
  // Inefficient to use strcat() here since it will have to
  // search for the \0 character in 'contents' to find where
  // to append the additional characters.
  strcat(contents, str.contents);
  len += str.len;
}

int String::compare_to(const String &str) const
{
  return strcmp(contents, str.contents);
}

void String::print() const
{
  cout << contents;
}

int String::length() const
{
  return len;
}

char String::element(int i) const
{
  // cerr is like cout, but is where error messages should go.
  if (i < 0 || i >= len) {
    cerr << "can't access location " << i
         << " of string \"" << contents << "\"" << endl;
    return '\0';
  }
  return contents[i];
}