PHP Cheatsheet for Rubyists

This is a quick cheatsheet for every Rubyist struggling to remember PHP syntax.

Variables

Ruby
Variable names can begin with an alphanumeric character or an underscore, but not a number. Local variables don't require any keywords. Variables are case sensitive (name and Name are two different variables). Conventionally, variables begin with a lowercase letter, and snakecase is used for multi-word variable names. You must assign a value to a variable when it is initialized, even if that value is 0, an empty string, or nil.

Instance variables are initialized with the @ symbol, class variables with two @@, and global variables with a $.

name = "Ginny"
Name = "Jennifer" 
p name # "Ginny"
p Name # "Jennifer"
your_name = "Ted"
_energy = nil
@@name = "Liz"
$tater = "Tot"

PHP
PHP variables always start with a dollar sign ($) and all variable declarations (all lines in PHP actually) must end with a semicolon (;). Other than that, PHP and Ruby variables have very similar rules. Variables names can start only with an alphanumeric character or an underscore, never a number. Variables are case sensitive.

However, you can declare a PHP variable without assigning it a value. Also, multi-word variables names can be camel- or snakecase.

<?php
$tatertots;
$name = "Liz";
$hours_of_sleep = 0;
$tatertots = 3;

Comments

Ruby
Single line comments begin with a hash.

p "Pay attention to this." #ignore this

Multiline comments begin with =begin and end with =end.

p "Print this."
=begin
Don't print this.
Also, don't look at this.
It's not pretty enough to be part of Ruby.
=end

It's very common to see hashes across multiple lines.

p "This is common"
#Even though
#they are
#for single lines
#technically

PHP
Single line comments start with two forward slashes ( // ). Multi-line PHP comments start with a forward slash and a star (/) and end with a star and a forward slash (/), similar to multiline CSS comments.

<?php
echo "This will print to the screen." //But this will be ignored.
/*
This will also be ignored
*/

Arrays

Ruby
There are two ways to create an array in Ruby:

my_array = Array.new
your_array = [1, 2, 3]

PHP
There is a grand total of one way to create an array in PHP:

<?php
$this_array = array(1, 2, 3);

Comments

[Jorge]

Just like Ruby, with PHP yo can create an array with $this_array = [1, 2, 3];