core-bundle/src/Resources/contao/library/Contao/Database/Result.php
public function __isset($strKey)
	{
		if (empty($this->arrCache))
		{
			$this->next();
		}

		return isset($this->arrCache[$strKey]);
	}
public function __isset($strKey)
	{
		if (empty($this->arrCache))
		{
			$this->next();
		}

		return isset($this->arrCache[$strKey]);
	}
Check whether a field exists

@param mixed $strKey The field name

@return boolean True if the field exists