Comparing bits

bits.php

<?php
// Always use a factor of 2 
$ADMIN = 1;
$TEACHER = 2;
$HUMAN = 4;

// This is how these numbers look in bits:
echo "Admin: " .decbin($ADMIN) . PHP_EOL;
echo "Teacher: ". decbin($TEACHER) . PHP_EOL;
echo "Human: ". decbin($HUMAN) . PHP_EOL;

// Let's combine two types:
$combined = $ADMIN | $TEACHER;
echo "Admin AND Teacher: " . decbin($combined) . PHP_EOL;

// Let's see what matches
if ($combined & $TEACHER) {
  echo "is Teacher\n";
} else {
  echo "is not Teacher\n";
}

if ($combined & $HUMAN) {
  echo "is Human\n";
} else {
  echo " is not Human\n";
}

if ($combined & ($TEACHER | $HUMAN)) {
  echo "is Teacher OR Human\n";
} else {
  echo " is not Teacher OR Human\n";
}