hello.php

<?php
// All PHP files start with <?php
// Two slashes is a comment, as you can see.

// We are going to start with variables.
// Variables are just like, a "container" to hold values.
// All variables in PHP start with a $ sign.
// Their names must start with a letter, not a number

$name = "Max"; // This is a string


$age = 14;     // This is an integer

// Let's print something to the screen!

echo "Hello, my name is $name and I am $age years old.\n";

// You can also do math with multiple integers.
echo "In 2 years, I will be " . ($age + 2) . " years old.\n";

// So, why did we need string concatenation here? I'll show you.

echo "In 2 years, I will be $age+2 years old.\n";
// You might expect the above to work, but it will print literally 14+2

// Here's another way we could have done it:
$futureAge = $age + 2;
echo "In 2 years, I will be $futureAge years old.\n";

// So that's basic variables.
// Another type of variable in PHP is called an Array.
// Arrays are just lists of values.

$ochatdMembers = ['Max', 'Shep', 'Shdwtek', 'beachpeach'];

echo "Again, my name is..." . $ochatdMembers[0] . "\n";

echo "My favorite person in the chat is... " . $ochatdMembers[1] . "\n";

echo "Here's a list of my friends from the chat:\n";

// We can add to an array after it's been created:
$ochatdMembers[] = "tweedsheep";
// Notice i didn't put a number between the []
// That's because PHP will automatically assign it to the next
// highest key value. In this case it would be 4 because
// we already have 0, 1, 2, and 3 assigned above.

$ochatdMembers[5] = "nezelbert"; // You can also specify a specific key too.

// Now let's make the list numbered!

foreach ($ochatdMembers as $i => $member) {
    // Now in the loop, $i will be our array key
    // But we don't want the list to start at 0...
    echo "   " . ($i + 1) . ". $member\n";
}

echo "...Yes, I'm friends with myself.\n";

echo "I have " . count($ochatdMembers) . " friends in the chat.\n";

// Array keys don't have to be numbers. They can also be strings.
$ochatdAges = [
    "Shep" => 28,
    "Max"  => 14,
    "Shdw" => 36,
    "Nez"  => 28,
];

// We can add a new key like this after the array has been made:
$ochatdAges["Faith"] = 21;


function addTwo($age) {
    return $age + 2;
}

function printName($name, $age, $term = "is") {
    echo "  - $name $term $age years old";
    if ($age > 25) {
        echo " (old fart)";
    }
    echo "\n";
}

echo "Here's a list of their ages:\n";

foreach ($ochatdAges as $name => $age) {
    printName($name, $age);
}

echo "In two years, this is how old everyone will be:\n";

foreach ($ochatdAges as $name => $age) {
    printName($name, addTwo($age), "will be");
}