Examples

Original string: hello world

Uppercase string: HELLO WORLD

Hello, Clifton!

In PHP, functions are blocks of reusable code that perform a specific task. Example:

• Built-in functions: Functions provided by PHP, such as strtoupper(), Converts a string to uppercase.
• User-defined functions: Functions created by the user. Define a function using the function keyword, followed by the function name and parameters. In the function, supply the code to be executed, and you can return a value using the return statement.
• Once a function is defined, you can call it with different arguments, making your code more readable, and easier to maintain.