Each array instance contains an internal pointer. By manipulating this pointer, different elements of an array can be retrieved from the same call at different times.
[each](<http://php.net/each>)
Each call to each()
returns the key and value of the current array element, and increments the internal array pointer.
$array = ["f" => "foo", "b" => "bar"];
while (list($key, $value) = each($array)) {
echo "$value begins with $key";
}
[next](<http://php.net/next>)
$array = ["Alpha", "Beta", "Gamma", "Delta"];
while (($value = next($array)) !== false) {
echo "$value\\n";
}
Note that this example assumes no elements in the array are identical to boolean false
. To prevent such assumption, use [key](<http://php.net/key>)
to check if the internal pointer has reached the end of the array:
$array = ["Alpha", "Beta", "Gamma", "Delta"];
while (key($array) !== null) {
echo current($array) . PHP_EOL;
next($array);
}
This also facilitates iterating an array without a direct loop:
class ColorPicker {
private $colors = ["#FF0064", "#0064FF", "#64FF00", "#FF6400", "#00FF64", "#6400FF"];
public function nextColor() : string {
$result = next($colors);
// if end of array reached
if (key($colors) === null) {
reset($colors);
}
return $result;
}
}