Link Post and Podcast Roundup: June 2021 Edition

June’s links.

Truthy and Falsy in PHP

In PHP it’s fairly common to see the if statement.

$booleanValue = true;
if ($booleanValue) {
    doSomething();
}

if (!$booleanValue) {
    dontDoSomethingElse();
}

We run across these all the time and can easily understand what happens when we pass them a true or false value. However what happens when the condition of the if statement is an object, a string, or a number?

What Is Truthy/Falsy?

Loosely typed languages like PHP allow us to use any kind of variable as if it was a boolean value in our if statements.

$valueString = 'hello';

if ($valueString) {
    doSomething();
}

When PHP needs to evaluate the if statement it converts our variable into something is can represent as a boolean. Ideally this would be a true or false but in PHP it will convert any variable into something it can represent as one of those two values. This is where “truthy” and “falsy” come in. A variable that isn’t true or false can be truthy or falsy.

Some Examples

Luckily for us there’s a logical consistency with how PHP type juggles our variables into truthy and falsy. For the most part the logic is that anything “empty” is falsy and anything with a value is truthy.

Numbers

0 is falsy but 1 or -1 are truthy.

<?php
if (0) {
    // not here
} else {
    echo "False";
}

if (1) {
    echo "True";
}

if (-1) {
    echo "True";
}

Arrays

Empty arrays are falsy but arrays with a value are truthy.

<?php
if ([]) {
    // not here
} else {
    echo "False";
}

if (['a value']) {
    echo "True";
}

Strings

Empty strings are falsy but strings with a value are truthy.

<?php
if ('') {
    // not here
} else {
    echo "False";
}

if ('a value') {
    echo "True";
}

Null

null values are falsy.

<?php
if (null) {
    // not here
} else {
    echo "False";
}

Displaying Our Vagrant VMs User Interface

Displaying the GUI

By default when Vagrant boots a VM it do so in a mode know as “headless mode”. Headless mode just means that no UI from the underlying provider is displayed. There are going to situations where we’re testing changes to our VM and we’ll be unable to access the VM using vagrant ssh (such as when we make a mistake altering the firewall rules). In order to display the UI we can add vb.gui = true to our virtualbox configuration.

Vagrant.configure("2") do |config|
  config.vm.box = "generic/ubuntu2004"

  config.vm.provider "virtualbox" do |vb|
    # Display the VirtualBox GUI when booting the machine
    vb.gui = true
  end
end

The next time we perform a vagrant up or vagrant reload VirtualBox will open and we’ll see the virtualbox displayed.

Then we can login using vagrant as the username and password and preform any actions we need to troubleshoot the problem.

Link Post and Podcast Roundup: May 2021 Edition

May’s links.

Always Use Type Declarations For Function Parameters and Return Values in PHP

What if I told you PHP has a built-in feature that will reduce the number of bugs in our code base? What if I told you it’s super simple to introduce into your daily coding routine? Would you be interested in using it?

In this article, we discuss why we should always use type declarations for function parameters and return values.

Getting Started with Test-Driven Development

This post is the companion piece to my presentation at Midwest PHP 2021.

Customizing the Amount Of RAM in Our Vagrant VMs

The Vagrant box that we pick will default to some amount of RAM. During our development, we’ll run into situations where we need to increase that amount. To do that we’re going to introduce a new section that’s specific to VirtualBox. We can then set the amount of RAM (in Megabytes) using the memory configuration setting.

Vagrant.configure("2") do |config|
  config.vm.box = "generic/ubuntu2004"

  config.vm.provider "virtualbox" do |vb|
    # Customize the amount of memory on the VM:
    vb.memory = "4096"
  end
end

The fun part about this setting is that because we’re configuring resources for a VM and not a physical device we can easily give it memory amounts that would be hard to get into a physical device. For example, we could give our VM 3GB of RAM.

Vagrant.configure("2") do |config|
  config.vm.box = "generic/ubuntu2004"

  config.vm.provider "virtualbox" do |vb|
    # Customize the amount of memory on the VM:
    vb.memory = "3072"
  end
end

Now if reload our VM and ssh into it we can check and see we now have 3 GB of RAM.

$ free -mh
              total        used        free      shared  buff/cache   available
Mem:          2.9Gi       452Mi       2.2Gi       3.0Mi       328Mi       2.3Gi
Swap:         1.9Gi          0B       1.9Gi

If you have questions related to vagrant or the PHP ecosystem in general you would like us to answer in future videos please ask them in the comments below.

Link Post and Podcast Roundup: April 2021 Edition

April’s links.

Better Know an Acronym: What is LAMP/MAMP/WAMP?

One of the hard parts about learning how to develop software is the minefield of acronyms that exists in the industry. The goal of this series of articles is to shine a light on an acronym so the next time another developer uses it in conversation you can follow along without missing a beat.

In this article, we’re going to be discussing the acronym LAMP. We’re picking this acronym because we’ve used it a couple of times in other articles and in doing so we have to use other acronyms which we’ll define in future articles. :-)

Creating a PHP 8 Development Environment Using Vagrant and Ubuntu 20.04

We’ve spent a lot of time discussing how to use Vagrant to create our development environment so now it’s time to bring everything we’ve learned together so we can finally develop some code.