add_query_arg( $args ): string

1139function add_query_arg( ...$args ) {1140	if ( is_array( $args[0] ) ) {1141		if ( count( $args ) < 2 || false === $args[1] ) {1142			$uri = $_SERVER['REQUEST_URI'];1143		} else {1144			$uri = $args[1];1145		}1146	} else {1147		if ( count( $args ) < 3 || false === $args[2] ) {1148			$uri = $_SERVER['REQUEST_URI'];1149		} else {1150			$uri = $args[2];1151		}1152	}1153 1154	$frag = strstr( $uri, '#' );1155	if ( $frag ) {1156		$uri = substr( $uri, 0, -strlen( $frag ) );1157	} else {1158		$frag = '';1159	}1160 1161	if ( 0 === stripos( $uri, 'http://' ) ) {1162		$protocol = 'http://';1163		$uri      = substr( $uri, 7 );1164	} elseif ( 0 === stripos( $uri, 'https://' ) ) {1165		$protocol = 'https://';1166		$uri      = substr( $uri, 8 );1167	} else {1168		$protocol = '';1169	}1170 1171	if ( str_contains( $uri, '?' ) ) {1172		list( $base, $query ) = explode( '?', $uri, 2 );1173		$base                .= '?';1174	} elseif ( $protocol || ! str_contains( $uri, '=' ) ) {1175		$base  = $uri . '?';1176		$query = '';1177	} else {1178		$base  = '';1179		$query = $uri;1180	}1181 1182	wp_parse_str( $query, $qs );1183	$qs = urlencode_deep( $qs ); // This re-URL-encodes things that were already in the query string.1184	if ( is_array( $args[0] ) ) {1185		foreach ( $args[0] as $k => $v ) {1186			$qs[ $k ] = $v;1187		}1188	} else {1189		$qs[ $args[0] ] = $args[1];1190	}1191 1192	foreach ( $qs as $k => $v ) {1193		if ( false === $v ) {1194			unset( $qs[ $k ] );1195		}1196	}1197 1198	$ret = build_query( $qs );1199	$ret = trim( $ret, '?' );1200	$ret = preg_replace( '#=(&|$)#', '$1', $ret );1201	$ret = $protocol . $base . $ret . $frag;1202	$ret = rtrim( $ret, '?' );1203	$ret = str_replace( '?#', '#', $ret );1204	return $ret;1205}