In this case, we give the parameter a default value of an empty array. This makes it optional, meaning the code should run fine without a parameter

gistfile1.php

<?php

/**
 * Custom Error Handler for E_RECOVERABLE_ERROR
 *
 * http://stackoverflow.com/a/2468534/285564
 *
 * @param $errno
 * @param $errstr
 * @param $errfile
 * @param $errline
 * @return bool
 * @throws ErrorException
 */
function myErrorHandler( $errno, $errstr, $errfile, $errline ) {

  if ( E_RECOVERABLE_ERROR===$errno ) {

    echo "'catched' catchable fatal error\n";

    throw new ErrorException( $errstr, $errno, 0, $errfile, $errline );

    // return true;
  }
  return false;

}

// Set up the custom error handler
set_error_handler( 'myErrorHandler' );

/**
 * Class Arr_Test
 */
class Arr_Test {

  /**
	 * Gives us a property to play with
	 * @var array
	 */
	var $objArr = array();

	/**
	 * Our object constructor
	 * @param array $myArr
	 */
	public function __construct( array $myArr = array() ) {

        // Initialize our property to the value of the passed param
		$this->objArr = $myArr;

		// call a method to test this code
		$this->print_myarr();
	}

	/**
	 * Simply iterates an array
	 */
	protected function print_myarr(){

		for ( $i=0; $i < count( $this->objArr ); $i++) {

			echo $this->objArr[$i]; // this would fail if our property is not an array

		}
	}

}

try {

	$myObj1 = new Arr_Test( );

} catch (Exception $e) {

	echo $e->getMessage();

}