WordPress at a glance
function is not described

WP_Rewrite::using_permalinks() public WP 1.5.0

Determines whether permalinks are being used.

This can be either rewrite module or permalink in the HTTP query string.

It's a method of the class: WP_Rewrite{}

No Hooks.

Return

true/false. True, if permalinks are enabled.

Usage

$WP_Rewrite = new WP_Rewrite();
$WP_Rewrite->using_permalinks();

Changelog

Since 1.5.0 Introduced.

Code of WP_Rewrite::using_permalinks() WP 5.5.1

<?php
public function using_permalinks() {
	return ! empty( $this->permalink_structure );
}