PHP cheatsheet

Hello world

hello.php

<?php
function greetMe($name): string
{
    return "Hello, " . $name . "!";
}

$message = greetMe($name);
echo $message;

All PHP files start with <?php.

See: PHP tags

Objects

<?php

$fruitsArray = array(
    "apple" => 20,
    "banana" => 30
);
echo $fruitsArray['banana'];

Or cast as object

<?php

$fruitsObject = (object) $fruits;
echo $fruitsObject->banana;

Inspecting objects

<?php
var_dump($object)

Prints the contents of a variable for inspection.

See: var_dump

Classes

class Person
{
    public $name = '';
}

$person = new Person();
$person->name = 'bob';

echo $person->name;

Getters and setters

class Person 
{
    private $name = '';

    public function getName(): string
    {
        return $this->name;
    }

    public function setName(string $name)
    {
        $this->name = $name;
        return $this;
    }
}

$person = new Person();
$person->setName('bob');

echo $person->getName();

isset vs empty


$options = [
    'key' => 'value',
    'blank' => '',
    'nothing' => null,
];

var_dump(isset($options['key']), empty($options['key'])); // true, false
var_dump(isset($options['blank']), empty($options['blank'])); // true, true
var_dump(isset($options['nothing']), empty($options['nothing'])); // false, true