Why modern PHP matters - See It in Action

Why Modern PHP Matters

📖 Scenario: Imagine you are building a simple website that shows a list of your favorite movies. You want to use PHP to create this list and display it nicely on the page. Using modern PHP features will help you write cleaner, safer, and faster code.

🎯 Goal: You will create a PHP script that stores a list of movies, sets a minimum rating to filter good movies, uses a modern PHP loop to select movies above that rating, and finally prints the filtered list.

📋 What You'll Learn

Create an associative array called $movies with exact movie titles as keys and their ratings as values.

Create a variable called $minRating and set it to 7.

Use a foreach loop with $title and $rating to filter movies with ratings greater than or equal to $minRating into a new array called $goodMovies.

Print the $goodMovies array using print_r.

💡 Why This Matters

🌍 Real World

Filtering and displaying data is a common task in websites and apps, such as showing only good reviews or popular items.

💼 Career

Understanding modern PHP basics like associative arrays, loops, and filtering helps you write clean and efficient code used in many web development jobs.

1

DATA SETUP: Create the movies array

Create an associative array called $movies with these exact entries: 'Inception' => 8, 'Twilight' => 5, 'Interstellar' => 9, 'Cats' => 3, 'The Matrix' => 9.

PHP

<?php
// Create the movies array with exact titles and ratings
// Your code here

Hint

Use square brackets [] to create the array and separate each movie with a comma.

2

CONFIGURATION: Set the minimum rating

Create a variable called $minRating and set it to 7.

PHP

 8,
    'Twilight' => 5,
    'Interstellar' => 9,
    'Cats' => 3,
    'The Matrix' => 9
];
// Set the minimum rating to 7
// Your code here

Hint

Just assign the number 7 to the variable $minRating.

3

CORE LOGIC: Filter movies with rating >= minRating

Use a foreach loop with variables $title and $rating to iterate over $movies. Inside the loop, add movies with $rating >= $minRating to a new array called $goodMovies.

PHP

 8,
    'Twilight' => 5,
    'Interstellar' => 9,
    'Cats' => 3,
    'The Matrix' => 9
];

$minRating = 7;
// Create an empty array called $goodMovies
// Use foreach to add movies with rating >= $minRating to $goodMovies
// Your code here

Hint

Start with an empty array $goodMovies = [];. Then use foreach ($movies as $title => $rating) and inside an if check, add the movie to $goodMovies.

4

OUTPUT: Print the filtered movies

Use print_r to display the $goodMovies array.

PHP

 8,
    'Twilight' => 5,
    'Interstellar' => 9,
    'Cats' => 3,
    'The Matrix' => 9
];

$minRating = 7;

$goodMovies = [];
foreach ($movies as $title => $rating) {
    if ($rating >= $minRating) {
        $goodMovies[$title] = $rating;
    }
}
// Print the $goodMovies array
// Your code here

Hint

Use print_r($goodMovies); to show the filtered list.

Practice

1. Why is using modern PHP versions important for developers?

easy

A. Because it offers new features that improve code safety and readability

B. Because older PHP versions run faster on all servers

C. Because modern PHP removes all bugs automatically

D. Because it allows running PHP code without a web server

Solution

1. Step 1: Understand the benefits of modern PHP

   Modern PHP versions introduce features like typed properties and arrow functions that help write safer and clearer code.

2. Step 2: Evaluate the options

   Only Because it offers new features that improve code safety and readability correctly states the importance of new features improving safety and readability. Other options are incorrect or misleading.

3. Final Answer:

   Because it offers new features that improve code safety and readability -> Option A

4. Quick Check:

   Modern PHP = safer, clearer code [OK]

Hint: Focus on benefits of new features in modern PHP [OK]

Common Mistakes:

• Thinking older PHP is always faster
• Believing modern PHP fixes bugs automatically
• Confusing PHP execution environment

2. Which of the following is the correct syntax for an arrow function introduced in modern PHP?

easy

A. function($x) { return $x * 2; }

B. fn($x) => $x * 2;

C. arrow($x) => $x * 2;

D. fn $x => { $x * 2 }

Solution

1. Step 1: Recall arrow function syntax in PHP

   Modern PHP uses fn($params) => expression; for arrow functions.

2. Step 2: Compare options

   fn($x) => $x * 2; matches the correct syntax. function($x) { return $x * 2; } is a traditional anonymous function. Options C and D have invalid syntax.

3. Final Answer:

   fn($x) => $x * 2; -> Option B

4. Quick Check:

   Arrow function syntax = fn(params) => expression [OK]

Hint: Look for 'fn' keyword with arrow => syntax [OK]

Common Mistakes:

• Using 'function' keyword for arrow functions
• Missing parentheses around parameters
• Incorrect placement of braces or arrows

3. What will be the output of this PHP code using typed properties?

class User {
  public int $id;
  public string $name;
  public function __construct(int $id, string $name) {
    $this->id = $id;
    $this->name = $name;
  }
}
$user = new User(5, 'Anna');
echo $user->id . ' - ' . $user->name;

medium

A. Error: Typed property must be initialized

B. 0 -

C. 5 - Anna

D. Anna - 5

Solution

1. Step 1: Understand typed properties initialization

   The constructor sets $id to 5 and $name to 'Anna', so properties are properly initialized.

2. Step 2: Check output of echo statement

   Echo prints $user->id (5), then ' - ', then $user->name ('Anna').

3. Final Answer:

   5 - Anna -> Option C

4. Quick Check:

   Typed properties initialized correctly = 5 - Anna [OK]

Hint: Check constructor sets typed properties before use [OK]

Common Mistakes:

• Assuming uninitialized typed properties cause error here
• Mixing order of output values
• Confusing property types with values

4. Identify the error in this modern PHP code snippet:

price = $price;
  }
}
$product = new Product('100');
echo $product->price;

medium

A. Fatal error: Cannot access property

B. No error, outputs 100

C. Syntax error due to missing semicolon

D. TypeError because string '100' is passed instead of int

Solution

1. Step 1: Check constructor parameter type

   The constructor expects an int for $price.

2. Step 2: Analyze argument passed

   The argument passed is a string '100', which causes a TypeError in strict typing mode.

3. Final Answer:

   TypeError because string '100' is passed instead of int -> Option D

4. Quick Check:

   Typed property expects int, string given = TypeError [OK]

Hint: Match argument types exactly with typed properties [OK]

Common Mistakes:

• Assuming PHP auto-converts string to int in strict mode
• Ignoring type declarations in constructor
• Confusing syntax errors with type errors

5. You want to update legacy PHP code to use modern features for better security and performance. Which approach best applies modern PHP advantages?

hard

A. Add typed properties, use arrow functions, and enable strict types

B. Remove all type hints and use global variables for speed

C. Keep old code but add comments about modern PHP

D. Use eval() to run code faster and avoid errors

Solution

1. Step 1: Identify modern PHP features for improvement

   Typed properties, arrow functions, and strict typing improve code safety and performance.

2. Step 2: Evaluate options for best practice

   Add typed properties, use arrow functions, and enable strict types applies these features correctly. Options A, B, and D either reduce safety or do not improve code.

3. Final Answer:

   Add typed properties, use arrow functions, and enable strict types -> Option A

4. Quick Check:

   Modern PHP = typed properties + arrow functions + strict types [OK]

Hint: Use new PHP features to improve code safety and speed [OK]

Common Mistakes:

• Ignoring type safety for speed
• Relying on eval() which is insecure
• Not updating code, only commenting