[php] PHP, getting variable from another php-file

using include 'page1.php' in second page is one option but it can generate warnings and errors of undefined variables.
Three methods by which you can use variables of one php file in another php file:

• use session to pass variable from one page to another
  method:
  first you have to start the session in both the files using php command
  

  sesssion_start();
  then in first file consider you have one variable
  $x='var1';
  

  now assign value of $x to a session variable using this:
  $_SESSION['var']=$x;
  now getting value in any another php file:
  $y=$_SESSION['var'];//$y is any declared variable

• using get method and getting variables on clicking a link
  method
  

  <a href="page2.php?variable1=value1&variable2=value2">clickme</a>
  getting values in page2.php file by $_GET function:
  $x=$_GET['variable1'];//value1 be stored in $x
$y=$_GET['variable2'];//vale2 be stored in $y

• if you want to pass variable value using button then u can use it by following method:
  

  $x='value1'
<input type="submit" name='btn1' value='.$x.'/>
  in second php
  $var=$_POST['btn1'];