Array Dot Notation
Array dot notation is a convention for addressing a value nested inside a multi-dimensional array using a single string of keys separated by dots, such as 'a.b.c', instead of chaining several square-bracket accesses.
PHP has no native support for dot notation: writing $array['a.b.c'] only looks for a single key literally named a.b.c. To resolve the path and read or write the nested value, the string must be split on the dots and each segment used to walk down the array, either with a hand-written loop or with a helper function or package.
Dot notation is commonly used by frameworks and libraries to give a compact syntax for reading configuration values or deeply nested data, such as Laravel’s Arr::get($array, 'a.b.c') or Symfony’s property access component.
<?php
function arrayGetDot(array $array, string $path, mixed $default = null): mixed {
foreach (explode('.', $path) as $key) {
if (!is_array($array) || !array_key_exists($key, $array)) {
return $default;
}
$array = $array[$key];
}
return $array;
}
$config = ['db' => ['host' => 'localhost', 'port' => 5432]];
echo arrayGetDot($config, 'db.host'); // localhost
?>