[string$numeric_prefix = ""],
[string|null$arg_separator = null],
[int$encoding_type = PHP_QUERY_RFC1738]
Generates a URL-encoded query string from the associative (or indexed) array provided.
May be an array or object containing properties.
If data is an array, it may be a simple one-dimensional structure, or an array of arrays (which in turn may contain other arrays).
If data is an object, then only public properties will be incorporated into the result.
If numeric indices are used in the base array and this parameter is provided, it will be prepended to the numeric index for elements in the base array only.
This is meant to allow for legal variable names when the data is decoded by PHP or another CGI application later on.
arg_separator.output is used to separate arguments but may be overridden by specifying this parameter.
By default, PHP_QUERY_RFC1738.
If encoding_type is PHP_QUERY_RFC1738, then encoding is performed per RFC 1738 and the application/x-www-form-urlencoded media type, which implies that spaces are encoded as plus (+) signs.
If encoding_type is PHP_QUERY_RFC3986, then encoding is performed according to RFC 3986, and spaces will be percent encoded (%20).
Returns a URL-encoded string.