$ this-> var或$ var

Question

I just started using OOP / CodeIgniter. I want to get assign the form input to variables. I wonder which one I should use $this -> var or $var and how they differ from each other? Thanks.

For example

$agree = $this -> input -> post( 'agree' );

OR

$this -> agree = $this -> input -> post( 'agree' );

Both will work fine like:

if ($agree) { }

OR

if ($this -> agree){ }

Thanks

Answer 1

It's a matter of scope

<?php
    class Example extends CI_Controller
    {
        private $agree1;

        public function __construct()
        {
            parent::__construct();
        }

        public function index()
        {
            $agree2 = $this->input->post( 'agree' );
            $this->agree1 = $this->input->post( 'agree' );

            // within this context both are accessable
            // these will print the same
            var_dump($agree2);
            var_dump($this->agree1);

            // call the helper function
            $this->helper();
        }

        private function helper()
        {
            // within this context $agree2 is not defined
            // these will NOT print the same. Only the 2nd will print the content of the post
            var_dump($agree2);
            var_dump($this->agree1);
        }
    }
?>