What are common pitfalls when using PHP arrays and indexes?

One common pitfall when using PHP arrays and indexes is trying to access an index that does not exist, which can result in errors or unexpected behavior. To avoid this, always check if the index exists before trying to access it using functions like isset() or array_key_exists(). Another pitfall is using non-integer values as indexes in arrays, which can lead to confusion and errors. It's best practice to use integers or strings as indexes for clarity and consistency.

// Check if index exists before accessing it
if (isset($array['key'])) {
    // Access the index if it exists
    $value = $array['key'];
}

// Using integers or strings as indexes for clarity and consistency
$indexedArray = [
    0 => 'first value',
    1 => 'second value',
    2 => 'third value'
];

$associativeArray = [
    'key1' => 'value1',
    'key2' => 'value2',
    'key3' => 'value3'
];