Magento 2: Overide the Block file

Question

How can in override the Block file.I need to override the below file.

vendor/magento/module-theme/Block/Html/Pager.php

protected $_availableLimit = [10 => 10, 20 => 20, 50 => 50];
protected $_availableLimit = [5 => 5, 10 => 10, 20 => 20, 50 => 50];

Also, I need to show 2 reviews per 1 page then what is the limit which will I have to set for above?

Please help me !!!

Answer 1

For Overriding files:

Vendor/Module/etc/di.xml

<?xml version="1.0"?>
<config xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="urn:magento:framework:ObjectManager/etc/config.xsd">
     <preference
            for="vendor\magento\module-theme\Block\Html\Pager"
            type="Vendor\Module\Block\Html\Pager"
    />
</config>

Then in Vendor\Module\Block\Html\Pager.php

<?php

namespace Vendor\Module\Block\Html;

class Pager extends \vendor\magento\module-theme\Block\Html\Pager {
 //do whatever you like
}

then run commands:

php bin/magento setup:di:compile

also run upgrade if you installing module first time