Functions and Libraries #3

Lesson 3: Functions and Libraries

3.1 Function Definition and Calling

Functions are blocks of code that perform a specific task. Here's an example of how to define and call a function:

This program will display "Hello, John!

3.2 Content Manipulation

Functions can also be used for text processing and array operations. Here's a simple example:

This program converts the text "hello world" to uppercase letters and displays it on the screen.

3.3 Using the Library

In PHP, you can use built-in libraries or external libraries that you include. For example, use an external library with a basic math function:

3.4 Function Parameters and Return Values

Functions can take parameters and return values:

This example shows a function that multiplies two numbers and returns the result.

In this tutorial we have learned the basics of functions and how to use the library. In the next tutorial we will look at working with HTML forms and connecting to a MySQL database. If you have any questions about the topics so far, feel free to ask!