PHP 7: Real World Application Development

Uniform variable syntax

Most of the time, we may face a situation in which the method, variable, or classes names are stored in other variables. Take a look at the following example:

$objects['class']->name;

In the preceding code, first, $objects['class'] will be interpreted, and after this, the property name will be interpreted. As shown in the preceding example, variables are normally evaluated from left to right.

Now, consider the following scenario:

$first = ['name' => 'second'];
$second = 'Howdy';

echo $$first['name'];

In PHP 5.x, this code would be executed, and the output would be Howdy. However, this is not inconsistent with the left-to-right expression evaluation. This is because $$first should be evaluated first and then the index name, but ...