Amazon EC2 Server上的PHP语法错误（正在开发中）

Question

I have the following line of code

foreach ($_SESSION['ini']->infrastructure()['buildings'] as $key => $value)

The variable $_SESSION['ini'] holds an object which reads various .ini files and holds their values in memory. It then returns individual sets of .ini variables as arrays when its functions are called. infrastructure() is such a function, and it returns a matrix. I only want the ['buildings'] array out of that matrix. The loop works fine on my development server. However, when I upload the code to the Amazon EC2 server, the server throws the following error:

Parse error: syntax error, unexpected '['

I assume that this is a reference to the practice of trying to grab the ['buildings'] array straight from the return value of the function, and indeed, the following code works fine on the EC2 server:

$placeholder = $_SESSION['ini']->infrastructure();
foreach ($placeholder['buildings'] as $key => $value)

Can anyone explain what would cause this variation in proper syntax between development and production, and how I can fix the EC2 server to work with the development code? I would prefer not to recode everything with the '$placeholder' approach, because it is less efficient, and because I use this syntax a lot throughout the project.

Answer 1

Seems like your PHP version on your EC2 is less than 5.4. Function array dereferencing is allowed only after versions from 5.4.

The function array dereferencing..

infrastructure()['buildings']

Since you know how to fix it this error, I am not going to write up. It is just the version why the code didn't work on your EC2.

Answer 2

The issue is most likely with this:

$_SESSION['ini']->infrastructure()['buildings']

Support for function array dereferencing wasn't added until PHP 5.4, so your EC2 instance is most likely running a version lower than that.

See: http://php.net/manual/en/migration54.new-features.php

You can fix it by just storing the results of the function in a variable:

$var = $_SESSION['ini']->infrastracture();
foreach ($var['buildings'] as $key => $value)

Or you can upgrade PHP versions on your EC2 instance if you want to keep using the syntax.