Question

In php, would the function count work also on a JSON object? Will it return the number of elements in the object? Or does this function only work for an array?

count($varJSONobject);

Answer 1

There’s no such thing as a JSONobject in PHP (unless it’s some user-defined something or other). There are only arrays or stdClass instances generated by json_decode^docs, which can be used with count.

It’s possible to make an object respond to count by having the object implement the Countable^docs interface.

For the sake of completeness, consider the following count results:

$test = new stdClass;
$test->prop1 = 1;
$test->prop2 = 1;
var_dump(count($test)); // 1

$test = (array) $test;
var_dump(count($test)); // 2

class CountTest {
  public $prop1 = 1;
  public $prop2 = 1;
}

$test = new CountTest;
var_dump(count($test)); // 1

$test = (array) $test;
var_dump(count($test)); // 2

// class implementing Countable
class CountMe implements Countable { 
  protected $myCount = 3; 
  public function count(){ 
     return $this->myCount; 
  }
}
$test = new CountMe;
var_dump(count($test)); // 3