Intro to PHP

1<?php
2
3// Your first PHP program
4echo "Hello, World!";
5
6?>

1<?php
2
3$name = "Alice";
4$age = 14;
5$score = 98.5;
6
7// String concatenation uses the dot operator
8echo $name . " is " . $age . " years old";
9// Output: Alice is 14 years old
10
11?>

1<?php
2
3// Create an indexed array
4$colors = ["red", "green", "blue"];
5
6// Access by index (starts at 0)
7echo $colors[0];  // "red"
8
9// Add to the end
10$colors[] = "yellow";
11
12// Count elements
13echo count($colors);  // 4
14
15?>

1<?php
2
3// Key-value pairs (like a dictionary)
4$student = [
5    "name"  => "Alice",
6    "age"   => 14,
7    "grade" => "A"
8];
9
10echo $student["name"];  // "Alice"
11
12?>

1<?php
2
3$scores = [85, 92, 78, 96, 88];
4
5foreach ($scores as $score) {
6    echo $score . " ";
7}
8// Output: 85 92 78 96 88
9
10// With key and value
11foreach ($student as $key => $value) {
12    echo $key . ": " . $value . "\n";
13}
14// Output:
15// name: Alice
16// age: 14
17// grade: A
18
19?>

1<?php
2
3function greet($name, $time) {
4    return "Good " . $time . ", " . $name . "!";
5}
6
7echo greet("Alice", "morning");
8// Output: Good morning, Alice!
9
10?>

1<?php
2
3// Modern PHP 8 features
4
5// Named arguments
6str_contains(haystack: "Hello World", needle: "World");  // true
7
8// Match expression (like a cleaner switch)
9$status = match($code) {
10    200 => "OK",
11    404 => "Not Found",
12    500 => "Server Error",
13};
14
15?>

1<?php
2
3// A complete mini-program to try
4
5$languages = [
6    "PHP"        => 1995,
7    "JavaScript" => 1995,
8    "Python"     => 1991,
9    "Ruby"       => 1995,
10];
11
12foreach ($languages as $name => $year) {
13    $age = date("Y") - $year;
14    echo $name . " is " . $age . " years old\n";
15}
16
17?>