Defining methods

PHP course · Intermediate · Lesson 3/115

Learn to add methods (functions) inside a class.

Defining methods

A method is a function defined inside a class. A method starts with the function keyword; followed by the method name, parentheses and a body in curly braces.

Example: function showInfo() { echo "Product info"; }. Here showInfo is the method name; the parentheses are empty for now, for parameters. The method body can contain echo, return and other statements. Defining a method does not run it; it waits to be called.

Method body and parameters

The method body is the block of code between the curly braces. You can write output with echo, do calculations and return a value with return.

A method can take parameters in the parentheses. Example: function greet($name) { echo "Hello " . $name; }. A parameter is a value given from outside when the method is called. This lesson focuses on parameterless methods.

Exercise Add a method to the Product class

Define a class named Product. Add a method named showInfo; in the body write echo "Product info" . "\n";. Do not call the method yet. After the class, write echo "Method defined" . "\n";.

Show example solution

Inside class Product { } add function showInfo() { echo ...; }, then echo after the class.
Example solution:
<?php
// Define the Product class and the showInfo method
class Product {
    function showInfo() {
        echo "Product info" . "\n";
    }
}
echo "Method defined" . "\n";

Test yourself

Match the parts of a method

function

Keyword
showInfo

Method name
()

Parameter parentheses
{ echo ...; }

Body

Complete the method definition

class Product {
    ____ showInfo() {
        echo "Product info";
    }
}

Show answer

class Product {
    function showInfo() {
        echo "Product info";
    }
}

Which is a valid method definition inside a class?
- function showInfo() { }
- method showInfo() { }
- def showInfo() { }
- showInfo() { }
Show answer

function showInfo() { } — Correct. The function keyword, method name, parentheses and braces form a method.

Defining methods