PHP next function

The PHP next() function moves the internal pointer to the next position in the array and returns the value of the array element at that position.

next(array &$array): mixed

$nextvalue = next($array);

Parameters

$array – the array whose pointer will be changed to the next position.

Returns

mixed (can be any value) – the value of the next element

false – in case the array has no more elements

PHP next examples

First of all, let’s do a simple example with any array.

$autos = array("Toyota", "Ford", "Chevrolet", "Nissan", "Honda");

$nextvalue= next($autos);
echo $nextvalue;

The next function can also be used to iterate through an array using while, although for this purpose I would recommend foreach. Let’s see an example that we saw before:

<?php
$array = array(
    'fruit1' => 'apple',
    'fruit2' => 'orange',
    'fruit3' => 'grape',
    'fruit4' => 'apple',
    'fruit5' => 'apple');

// this cycle echoes all associative array
// key where value equals "apple"
while ($fruit_name = current($array)) {
    if ($fruit_name == 'apple') {
        echo key($array), "\n";
    }
    next($array);
}
?>

fruit1
fruit4
fruit5

This is an excellent example for you to see how we can iterate with while, but keep in mind what we said before, remember that if our array contains false this can cause us problems.

Let’s see one more example about this: if we have the following array, how would we iterate through it using while and next?

$persona = array(
    "nombre" => "Juan",
    "edad" => 25,
    "estudiante" => false,
    "ocupacion" => "Carpintero"
);

To iterate through this array, we should do something like this:

$persona = array(
    "nombre" => "Juan",
    "edad" => 25,
    "estudiante" => false,
    "ocupacion" => "Carpintero"
);

while (true) {
    $valor = current($persona);
    $clave = key($persona);
    
    if ($clave === null) {
        break;
    }

    echo "Clave: $clave, Valor: $valor\n";

    // Mover el puntero al siguiente elemento
    next($persona);
}

Clave: nombre, Valor: Juan
Clave: edad, Valor: 25
Clave: estudiante, Valor: 
Clave: ocupacion, Valor: Carpintero

Notice that we have done a while true, this will make this loop execute continuously unless $key is null, this is obtained using the PHP key function.

If $key is null we will call a break which will make us exit this loop.