PHP Difference between array() and []

159
votes

I'm writing a PHP app and I want to make sure it will work with no errors.

The original code:

<?php
$data = array('name' => 'test',
              'id'   => 'theID');

echo form_input($data);
?>

Would the following work with no errors or is not recommended for some reason?

<?= form_input(['name' => 'test', 'id' => 'theID']); ?>

Are there any difference?

I've looked again the data about array() and the short array method with square brackets [] in PHP.net but I'm not sure.

And also, is the short php tag <?= ?> fine for echoing? Is there any version issue? (provided is enabled in php.ini)

5
phparrayssyntaxsquare-bracket
Short array syntax was introduced in PHP 5.4, there is no difference and the old method will not be removed, so it's safe to use either. Short tags are usually frowned upon, I wouldn't use them. – JimL
Tks, any reference/reason on not using php short tags? – Mr.Web
Although <?= ?> aren't actually considered shorttags, they aren't disabled with the standard shorttags afaik so they should be fine for simple echoes. – Alexander Varwijk
See php.net/manual/en/ini.core.php#ini.short-open-tag. – str
Interesting read on <?= ?> tags. According to one of the comments "Rasmus Lerdorf himself made that very commit" programmers.stackexchange.com/questions/151661/… – johnsnails

5 Answers

239
votes

Following [] is supported in PHP >= 5.4:

['name' => 'test', 'id' => 'theID']

This is a short syntax only and in PHP < 5.4 it won't work.

24
votes

As of 2019, it has been 7 years since the [] syntax was added. That is long enough to drop array() except in old legacy programs, in my opinion.

6
votes

If you are using 5.3 or previous version then you can't use [] as an array as well as associative array. If you are using 5.4 or later version of PHP then you can use either array() or [] to create an array, associative array or even multidimensional array.

2
votes

And regarding the <?= ?> part of the question: it is largely not frowned upon, at least not in 2019.

  1. A good technical breakdown: https://softwareengineering.stackexchange.com/questions/151661/is-it-bad-practice-to-use-tag-in-php
  2. A note in PSR-1: Files MUST use only <?php and <?= tags.
  3. TL;DR: There is no reason you cannot or should not use it.
-20
votes

Using php 7.2, for me it seems rather then [I am a an array] {I am an array seems to work}. Difference is between {} and []. My code

<p>
  <label for="post_category"> Cat 1 </label>
  <input type="checkbox" name="post_category{first}" value="cat1">
  <br />
  <label for="post_category{second}"> Cat 2 </label>
  <input type="checkbox" name="post_category" value="cat2">
</p>