Block/Hello.php

<?php
namespace Icube\Training\Block;
 
class Hello extends \Magento\Framework\View\Element\Template
{
	public function __construct(
        \Magento\Framework\View\Element\Template\Context $context,
        \Icube\Training\Helper\Data $helper) {
        parent::__construct($context);
		$this->helper = $helper;
    }

    public function getHelloWorld()
    {
        return $this->helper->getTrainingHelper();
    }
}