Can You Add Values to an Array without a Key? - PHP Script Tips - Understanding PHP Arrays and Their Basic Operations

Can You Add Values to an Array with a Key? The answer is yes and no. The answer is yes, because you can add values without specifying any keys. The answer is no, because PHP will add a default integer key for you if you are not specifying a key. PHP follows these rules to assign you the default keys:

• Assign 0 as the default key, if there is no integer key exists in the array.
• Assign the highest integer key plus 1 as the default key, if there are integer keys exist in the array.

Here is a PHP example script:

<?php 
$mixed = array();
$mixed["Zero"] = "PHP";
$mixed[1] = "Perl";
$mixed["Two"] = "Java";
$mixed["3"] = "C+";
$mixed[""] = "Basic";
$mixed[] = "Pascal";
$mixed[] = "FORTRAN";
print("Array with default keys:\n");
print_r($mixed);
?>

This script will print:

Array with default keys:
Array
(
    [Zero] => PHP
    [1] => Perl
    [Two] => Java
    [3] => C+
    [] => Basic
    [4] => Pascal
    [5] => FORTRAN
)