system/HTTP/URI.php
public function getQuery(array $options = []): string
	{
		$vars = $this->query;

		if (array_key_exists('except', $options))
		{
			if (! is_array($options['except']))
			{
				$options['except'] = [$options['except']];
			}

			foreach ($options['except'] as $var)
			{
				unset($vars[$var]);
			}
		}
		elseif (array_key_exists('only', $options))
		{
			$temp = [];

			if (! is_array($options['only']))
			{
				$options['only'] = [$options['only']];
			}

			foreach ($options['only'] as $var)
			{
				if (array_key_exists($var, $vars))
				{
					$temp[$var] = $vars[$var];
				}
			}

			$vars = $temp;
		}

		return empty($vars) ? '' : http_build_query($vars);
	}
public function getQuery(array $options = []): string
	{
		$vars = $this->query;

		if (array_key_exists('except', $options))
		{
			if (! is_array($options['except']))
			{
				$options['except'] = [$options['except']];
			}

			foreach ($options['except'] as $var)
			{
				unset($vars[$var]);
			}
		}
		elseif (array_key_exists('only', $options))
		{
			$temp = [];

			if (! is_array($options['only']))
			{
				$options['only'] = [$options['only']];
			}

			foreach ($options['only'] as $var)
			{
				if (array_key_exists($var, $vars))
				{
					$temp[$var] = $vars[$var];
				}
			}

			$vars = $temp;
		}

		return empty($vars) ? '' : http_build_query($vars);
	}
Retrieve the query string

@param array $options

@return string