Param.php

<?php

namespace PhpParser\Node;

use PhpParser\Error;
use PhpParser\NodeAbstract;

class Param extends NodeAbstract
{
    /** @var null|string|Name Typehint */
    public $type;
    /** @var bool Whether parameter is passed by reference */
    public $byRef;
    /** @var bool Whether this is a variadic argument */
    public $variadic;
    /** @var string Name */
    public $name;
    /** @var null|Expr Default value */
    public $default;

    /**
     * Constructs a parameter node.
     *
     * @param string           $name       Name
     * @param null|Expr        $default    Default value
     * @param null|string|Name $type       Typehint
     * @param bool             $byRef      Whether is passed by reference
     * @param bool             $variadic   Whether this is a variadic argument
     * @param array            $attributes Additional attributes
     */
    public function __construct($name, Expr $default = null, $type = null, $byRef = false, $variadic = false, array $attributes = array()) {
        parent::__construct($attributes);
        $this->type = $type;
        $this->byRef = $byRef;
        $this->variadic = $variadic;
        $this->name = $name;
        $this->default = $default;

        if ($variadic && null !== $default) {
            throw new Error('Variadic parameter cannot have a default value', $default->getAttributes());
        }
    }

    public function getSubNodeNames() {
        return array('type', 'byRef', 'variadic', 'name', 'default');
    }
}