WP_AJAX-requestType.php

<?php

Class Example extends WP_AJAX
{
    protected $action = 'example';

    protected function run(){
    	echo $this->requestType(); // 'GET'

    	echo $this->requestType('GET'); // (bool) TRUE

    	echo $this->requestType('POST'); // (bool) FALSE

    	echo $this->requestType(['GET', 'PUT']); // (bool) TRUE

    	echo $this->requestType(['POST', 'PUT']); // (bool) FALSE

    }
}