Class obj

$X

An object to compare with $Y

$Y

An object to compare with $X

Comparing objects of the same class

$P1 = new stdClass();
$P1->x = 1.0;
$P1->y = 2.0;

$P2 = new stdClass();
$P2->x = 2.0;
$P2->y = 4.0;

$P3 = new stdClass();
$P3->x = 1.0;
$P3->y = 2.0;

echo 'Does $P1 equal to $P2? - ';
echo obj::eq($P1, $P2) ? 'Yes.' : 'No.';
echo "\n";
echo 'Does $P1 equal to $P3? - ';
echo obj::eq($P1, $P3) ? 'Yes.' : 'No.';

Does $P1 equal to $P2? - No.
Does $P1 equal to $P3? - Yes.

equals() evaluation

class Fraction {
  public $numerator, $denominator;

  function __construct($Numerator, $Denominator) {
    $this->numerator   = $Numerator;
    $this->denominator = $Denominator;
  }

  function quotient() {
    return $this->numerator / $this->denominator;
  }

  function equals($Fraction) {
    return $this->quotient() == $Fraction->quotient();
  }
}

$X = new Fraction(2, 1); // = 2/1
$Y = new Fraction(4, 2); // = 4/2

echo 'Does $X equal to $Y? - ';
echo obj::eq($X, $Y) ? 'Yes.' : 'No.';

Does $X equal to $Y? - Yes.

$X

An object to retrieve a property from

$Prop

The name of a property to get

$Alt

(optional) A fail-safe value

Demonstration

class Student {
  public $name;
  private $age;

  public function __construct($Name, $Age) {
    $this->name = $Name;
    $this->age = $Age;
  }
}

$student = new Student('Alice', 21);
var_dump( obj::get($student, 'name') );
// Because of $age is private and no getter method, you can never get it
var_dump( obj::get($student, 'age') );            // Alternates with NULL
var_dump( obj::get($student, 'age', 'Secret!') ); // Alternates with a string

string(5) "Alice"
NULL
string(7) "Secret!"

Calling a getter method

class Student {
  public $name;
  private $age;

  public function __construct($Name, $Age) {
    $this->name = $Name;
    $this->age = $Age;
  }

  // The getter method for $age
  public function getAge() {
    return $this->age;
  }
}

$student = new Student('Alice', 21);
var_dump( obj::get($student, 'name') );
var_dump( obj::get($student, 'age') );            // Invokes $student->getAge()
var_dump( obj::get($student, 'age', 'Secret!') ); // No alternation

string(5) "Alice"
int(21)
int(21)