Variables

All variables in PHP start with a dollar sign ($). Unlike many other languages, PHP does not have different types of variable for integers, floating-point numbers, arrays, or Booleans. They all start with a $, and all are interchangeable. As a result, PHP is a weakly typed language, which means you do not declare a variable as containing a specific type of data; you just use it however you want to.

Save the code in Listing 39.1 into a new file called ubuntu1.php.

Listing 39.1. Testing Types in PHP

<?php  $i = 10;  $j = "10";  $k = "Hello, world";  echo $i + $j;  echo $i + $k;?>

To run that script, bring up a console and browse to where you saved it. Then type this command:

matthew@seymour:~$ php ubuntu1.php

If PHP is installed correctly, ...

Get Ubuntu Unleashed 2013 Edition: Covering 12.10 and 13.04, Eighth Edition now with the O’Reilly learning platform.

O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.