Wordpress侧边栏看不到参数

I have page.php. There is a variable $number. If number is more than zero, I would like to load sidebar.php and print that number in sidebar.

page.php

<?php  
$number = 4; 

if($number): ?>

        <?php get_sidebar(); ?>

<?php endif; ?>

sidebar.php

<?php var_dump($number); ?>

Why doesn't sidebar.php see my variable?

Use global variable this will help you , check below complete code.

<?php  
global $number;
$number = 4; 

if($number): ?>

    <?php get_sidebar(); ?>

<?php endif; ?>

sidebar.php

<?php  global $number; 
       var_dump($number); ?>