you can create Helper file (Data.php) at this location Mageplaza/HelloWorld/Helper/Data.php
.
<?php
namespace Mageplaza\HelloWorld\Helper;
use Magento\Framework\App\Helper\AbstractHelper;
use Magento\Framework\App\Helper\Context;
use Magento\Store\Model\ScopeInterface;
class Data extends AbstractHelper
{
protected $context;
public function __construct(Context $context)
{
$this->context = $context;
parent::__construct($context);
}
public function isEnable()
{
return $this->scopeConfig->getValue('helloWorld/general/enable', ScopeInterface::SCOPE_STORE);
}
}
Now Write this code in phtml file :
<?php
$helper = \Magento\Framework\App\ObjectManager::getInstance()->get('Mageplaza\HelloWorld\Helper\Data');
if($helper->isEnable()) : ?>
//WRITE YOUR CODE HERE
<?php endif; ?>
if you want to created field in value set then below file create
etc/config.xml in your extension
<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:module:Magento_Store:etc/config.xsd">
<default>
<helloworld>
<general>
<enable>1</enable>
<price>100</price> <!-- here price is field name-->
---------<!--other fields-->
</general>
</helloworld>
</default>