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PHP list constructor
PHP list assign variables as if they were an array, at least that’s the definition on official page. I would say it assigns the elements of the array to variables, variables that will be created when we pass them as parameters to list
.
list()
only works with numeric arrays and assumes that numeric indexes start at 0.
Let’s first look at its description and syntax, and then we can conduct some tests to have a clearer understanding of the concept.
Description / Descripciónlist(mixed $var1, mixed ...$... = ?): arraySintaxis / Sintax
list($variable1,$variable2) =$mi_array;
Examples
Let’s start with a simple example that also uses the array_values
function.
$caracteristicas_auto = [ "marca" => "Toyota", "modelo" => "Camry", "año" => 2022, "color" => "Azul", "motor" => "2.5L", "tracción" => "Delantera" ]; list($marca, $modelo, $año, $color, $motor, $traccion) = array_values($caracteristicas_auto); echo "Marca: " . $marca . "<br>"; echo "Modelo: " . $modelo . "<br>"; echo "Año: " . $año . "<br>"; echo "Color: " . $color . "<br>"; echo "Motor: " . $motor . "<br>"; echo "Tracción: " . $traccion . "<br>";
Marca: Toyota Modelo: Camry Año: 2022 Color: Azul Motor: 2.5L Tracción: Delantera
Let’s look at another example to explore more features of list
.
$info = array('café', 'marrón', 'cafeína'); // Enumerar todas las variables list($bebida, $color, $energía) = $info; echo "El $bebida es $color y la $energía lo hace especial.\n"; // Enumerar algunas de ellas list($bebida, , $energía) = $info; echo "El $bebida tiene $energía.\n"; // U omitir solo la tercera list( , , $energía) = $info; echo "Necesito $energía!\n"; // list() no funciona con cadenas list($bar) = "abcde"; var_dump($bar); // NULL
El café es marrón y la cafeína lo hace especial. El café tiene cafeína. Necesito cafeína! NULL
The list
function can be used in conjunction with Heredoc, as you can create a list to then display on the screen in a clear way, thus helping the readability of the code.
Reference: https://www.php.net/manual/en/function.list.php
Category: en-php
Something wrong?
If you found an error or mistake in the content you can contact me on Twitter | @luisg2249_luis.
Warning
In PHP 5, `list()` assigns values starting from the rightmost parameter. In PHP 7, `list()` starts from the leftmost parameter.
If I were to recommend something, it would be not to use PHP `list` if you are on a version 5.x because in the future, if the server version is changed, it can lead to unexpected behaviors.