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1 <3 Speed & Throwable

Hey guys! I hate to start a tutorial off on a depressing note but... look... PHP 5 is dead. WAY dead. Like, it's not even supported anymore. PHP 5 is like that old, bad relationship that you just can't get out of. Hey, it's time to move on. You're better than PHP 5.

Also... did you know that PHP 7 is a full 2 numbers higher than PHP 5? I heard they skipped PHP 6 because 7 was just too awesome to fit into such a low number. Or... maybe because they messed up PHP 6. Anyways, let's pretend that it's because PHP 7 is so great... because it is.

This tutorial is about learning the important stuff... only. Look, you can spend hours reading the PHP 7 CHANGELOG. Believe us... we did it. I get it, they made a lot of stuff better... cool... but most of it isn't that critical. This means that we will not be talking about the spaceship operator... because it is apparently not a person who drives a flying saucer. Nope, it's an edge-case way to compare numbers and strings. So disappointing.

Speed Sells

So what is important in PHP 7? Honestly... the biggest selling point for upgrading is speed. PHP 7 performance is on point. To show it off, Zend made a cute infographic. Summary: PHP 7 equals zoooooom!

And that means you can take this to your manager and say:

Hey buddy! When we upgrade to PHP 7, our pages will be faster and we can turn off like 10 servers.

And then they'll throw you a parade and promote you to CEO. Enjoy.

Setting up the Project

And now that we know how to sell the upgrade to management, let's get into the cool technical stuff.

As always, you should definitely enjoy a snack during the tutorial... and code along with me! Download the course code from this page and unzip it. Inside, you'll find a fancy start/ directory with the same code you see here. Follow the README.md file to get things set up. The last step will be to find your favorite terminal, go to the project directory, and run:

php bin/console server:run

to start the built-in web server. Open up the project in your browser: http://localhost:8000.

Welcome to AquaNote! A project we've been building in our Symfony series. For this tutorial, it'll be a nice skeleton to start with.

Proper Error Handling

Ok, the first feature of PHP 7 that gets me excited is... proper error handling. Stay with me: I promise this is exciting!

At the root of the project, create a new file called play-exceptions.php. Inside, let's do something fun: like, write some really bad code! We'll call an undefinedFunction(). And below, I'll write "continue processing file", even though we know that's crazy! This script will blow up way before that line.

5 lines play-exceptions.php
<?php
undefinedFunction();
echo "\n\nContinue processing file...";

Find your terminal, open up a new tab, and run:

php play-exceptions.php

Fatal error! Woohoo!

Catching Errors

In PHP 5, we could catch exceptions... but not errors. Sure, you could try to work with the error handler... but that's confusing stuff! In PHP 7... they fixed things! We can finally catch errors.

Start with a normal try-catch block. But instead of catching Exception, catch \Throwable. Yes! In PHP 7, you can write bad code, catch it, and even print out the error message!

9 lines play-exceptions.php
<?php
try {
undefinedFunction();
} catch (\Throwable $error) {
echo 'Now if you write bad code, you can catch it! ' . $error->getMessage();
}
echo "\n\nContinue processing file...";

Try the file again:

php play-exceptions.php

Haha! It actually runs.

About Throwable

About this Throwable thingy: it's actually a core interface. Here's the deal: we still have the core Exception class. And now, there is also an Error class. And both Exception and Error implement the Throwable interface. So if you want to catch both exceptions and errors, catch \Throwable. If you want to only catch exceptions, then catch \Exception. And if you want to only catch errors, use catch \Error. It's quite elegant.

And, just like with exceptions, there are different types of errors, each with its own class. For example, TypeError is thrown when you're passing an argument of a wrong type to a function. And actually, that's our next topic: the new scalar type system and strict mode!

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