Cacher is the code snippet organizer for pro developers

<?php

// 1. To access Current Menu parameters
$app = JFactory::getApplication();
// Get active menu
$currentMenuItem = $app->getMenu()->getActive();
// Get params for active menu
$params = $currentMenuItem->params;
// Access param you want
$yourParameter = $params->get('yourParameter');
 
// 2. To access Menu parameters from a known Itemid
$app = JFactory::getApplication();
// Get Itemid from URL
$input  = JFactory::getApplication()->input;
$itemId = $input->get->get('Itemid', '0', 'INT');
// Get menu from Itemid
$menuItem = $app->getMenu()->getItem($itemId);
// Get params for menuItem
$params = $menuItem->params;
// Access param you want
$yourParameter = $params->get('yourParameter');