why do you give me this error Undefined variable:?

Question

why do you give me this error Undefined variable:?

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#1 by (4 votes)

5

Excuse me I'm new to PHP and I'm only doing tests so I do not know why this error is generated:

Notice: Undefined variable: firstName in   C: \ xampp \ htdocs \ Programming \ PHP \ prueba.php on line 8

Notice: Undefined property: person :: $ in   C: \ xampp \ htdocs \ Programming \ PHP \ prueba.php on line 8

Notice: Undefined variable: lastName in   C: \ xampp \ htdocs \ Programming \ PHP \ prueba.php on line 8

Notice: Undefined property: person :: $ in   C: \ xampp \ htdocs \ Programming \ PHP \ prueba.php on line 8

<?php

class person{
    var $firstName=null;
    var $lastName=null;

    function fullname(){
            return $this->$firstName . ' ' . $this->$lastName;
    }
}

$person1 = new person;
$person1->firstName = 'Samuel';
$person1->lastName = 'Vieyra';


exit($person1->fullname());
?>

Update1

<?php

class person{
    var $firstName=null;
    var $lastName=null;

    function fullname(){
            return $this->$firstName . ' ' . $this->$lastName;
    }
}

$person1 = new person();
$person1->firstName = 'Samuel';
$person1->lastName = 'Vieyra';


exit($person1->fullname());
?>

php

asked by Samuel Viema 06.07.2018 в 06:17

source

1 answer

Check that the value of a field complies with at least one of 3 conditions Identify null values in Laravel and MySQL

score 4 · Accepted Answer

It is a syntax error, it is due to the $ that refers to the property within the line return $this->$firstName . ' ' . $this->$lastName;

The correct thing would be

return $this->firstName . ' ' . $this->lastName;

Complete code:

class person{
    var $firstName=null;
    var $lastName=null;

    function fullname(){
            return $this->firstName . ' ' . $this->lastName;
    }
}

$person1 = new person;
$person1->firstName = 'Samuel';
$person1->lastName = 'Vieyra';


exit($person1->fullname());

I recommend reading the php object orientation documentation which is very complete, and it's going to help a lot!

Greetings and successes!