Default parameter values in PHP - Mini Project: Build & Apply

Default parameter values

📖 Scenario: Imagine you are creating a simple greeting system for a website. Sometimes visitors provide their name, and sometimes they don't. You want to greet them politely either way.

🎯 Goal: Build a PHP function that greets a user by name if given, or uses a default greeting if no name is provided.

📋 What You'll Learn

Create a function named greet with one parameter $name that has a default value.

Set the default value of $name to 'Guest'.

Inside the function, return a greeting string like 'Hello, NAME!' where NAME is the value of $name.

Call the function twice: once without any argument, and once with the argument 'Alice'.

Print the results of both function calls.

💡 Why This Matters

🌍 Real World

Default parameter values help make functions flexible and easier to use when some information is optional.

💼 Career

Understanding default parameters is important for writing clean, reusable code in PHP and many other programming languages.

1

Create the greet function with a default parameter

Write a PHP function named greet that has one parameter called $name with a default value of 'Guest'. Inside the function, return the string 'Hello, ' . $name . '!'.

PHP

<?php

// Define the greet function with default parameter
// Your code here

Need a hint?

Use = 'Guest' after the parameter $name to set the default value.

2

Call the greet function without arguments

Call the greet function without any arguments and store the result in a variable called $greeting1.

PHP

<?php

function greet($name = 'Guest') {
    return 'Hello, ' . $name . '!';
}

// Call greet without arguments and save to $greeting1
// Your code here

Need a hint?

Call greet() without any parameters to use the default value.

3

Call the greet function with the argument 'Alice'

Call the greet function with the argument 'Alice' and store the result in a variable called $greeting2.

PHP

<?php

function greet($name = 'Guest') {
    return 'Hello, ' . $name . '!';
}

$greeting1 = greet();

// Call greet with 'Alice' and save to $greeting2
// Your code here

Need a hint?

Pass 'Alice' as the argument to greet to override the default.

4

Print both greetings

Print the variables $greeting1 and $greeting2 each on a new line using echo.

PHP

<?php

function greet($name = 'Guest') {
    return 'Hello, ' . $name . '!';
}

$greeting1 = greet();
$greeting2 = greet('Alice');

// Print $greeting1 and $greeting2 each on a new line
// Your code here

Need a hint?

Use echo to print each greeting followed by a newline character "\n".