php $ this->函数中的变量不能像我希望的那样[关闭]

Question

I'm learning PHP and reading through a Robin Nixon book. I'm having trouble with this code:

<?php 
class Centre
{
    public $centre_name; // String: The name of the centre
    public $tagline; // String: The centre's tagline

        // Set the centres details. This will later be done through a form.
    function set_details()
    {
        $this->centre_name = "YMCA";
        $this->tagline = "Lets all go to the Y";
    }

        // Display the centres details. 
    function display()
    {
        echo "Centre Name - " . $centre->centre_name . "<br />";
        echo "Centre Tagline - " . $centre->tagline . "<br />";
    }
} 

?>

<?php 
    $centre = new Centre();
    $centre->set_details();
    $centre->display();
?>

Right now this is outputing: Centre Name - Centre Tagline - So the variables are being set. Am I using $this->variable = "whatever"; correctly?

Answer 1

change this

function display()
{
    echo "Centre Name - " . $centre->centre_name . "<br />";
    echo "Centre Tagline - " . $centre->tagline . "<br />";
}

to

function display()
{
    echo "Centre Name - " . $this->centre_name . "<br />";
    echo "Centre Tagline - " . $this->tagline . "<br />";
}

you used $centre instead of $this.