php自动加载代码实例详解

abstract class DaysOfWeek
{
  const Sunday = 0;
  const Monday = 1;
  // etc.
}

$today = DaysOfWeek::Sunday;

abstract class BasicEnum {
  private static $constCacheArray = NULL;

  private static function getConstants() {
    if (self::$constCacheArray == NULL) {
      self::$constCacheArray = [];
    }
    $calledClass = get_called_class();
    if (!array_key_exists($calledClass, self::$constCacheArray)) {
      $reflect = new ReflectionClass($calledClass);
      self::$constCacheArray[$calledClass] = $reflect - > getConstants();
    }
    return self::$constCacheArray[$calledClass];
  }

  public static function isValidName($name, $strict = false) {
    $constants = self::getConstants();

    if ($strict) {
      return array_key_exists($name, $constants);
    }

    $keys = array_map('strtolower', array_keys($constants));
    return in_array(strtolower($name), $keys);
  }

  public static function isValidValue($value, $strict = true) {
    $values = array_values(self::getConstants());
    return in_array($value, $values, $strict);
  }
}

abstract class DaysOfWeek extends BasicEnum {
  const Sunday = 0;
  const Monday = 1;
  const Tuesday = 2;
  const Wednesday = 3;
  const Thursday = 4;
  const Friday = 5;
  const Saturday = 6;
}

DaysOfWeek::isValidName('Humpday');         // false
DaysOfWeek::isValidName('Monday');          // true
DaysOfWeek::isValidName('monday');          // true
DaysOfWeek::isValidName('monday', $strict = true);  // false
DaysOfWeek::isValidName(0);             // false

DaysOfWeek::isValidValue(0);             // true
DaysOfWeek::isValidValue(5);             // true
DaysOfWeek::isValidValue(7);             // false
DaysOfWeek::isValidValue('Friday');         // false

spl_autoload_register(function ($classname) {
  include $classname . '.php';
});
$object = new Class1();
$object2 = new Class2();

function myFunc() {
  for ($i = 0; $i < func_num_args(); $i++) {
    printf("Argument %d: %s\n", $i, func_get_arg($i));
  }
}

/*
Argument 0: a
Argument 1: 2
Argument 2: 3.5
*/
myFunc('a', 2, 3.5);