Function declaration and calling in PHP - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a function in PHP?

A function is a reusable block of code that performs a specific task. You can call it whenever you need that task done.

beginner

How do you declare a function in PHP?

Use the <code>function</code> keyword, followed by the function name and parentheses. Inside curly braces, write the code to run when the function is called.<br><br>Example:<br><code>function greet() { echo 'Hello!'; }</code>

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How do you call a function in PHP?

Write the function name followed by parentheses. If the function needs inputs, put them inside the parentheses.<br><br>Example:<br>greet();

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What happens if you call a function that has parameters?

You must provide the required values (arguments) inside the parentheses when calling the function. These values are used inside the function.<br><br>Example:<br><code>function sayHello($name) { echo "Hello, $name!"; }<br>sayHello('Alice');</code>

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Can a function return a value in PHP? How?

Yes, a function can send back a value using the <code>return</code> keyword. This lets you use the result elsewhere.<br><br>Example:<br><code>function add($a, $b) { return $a + $b; }<br>$sum = add(3, 4);</code>

Which keyword is used to declare a function in PHP?

A function

B def

C func

D declare

In PHP, the keyword function is used to declare a function.

How do you call a function named greet in PHP?

A call greet();

B run greet();

C function greet();

D greet();

To call a function, just write its name followed by parentheses: greet();

What will this code output?<br>

function sayHi() { echo 'Hi!'; }<br>sayHi();

A Error

B sayHi

C Hi!

D Nothing

The function sayHi prints 'Hi!' when called.

What is needed when calling a function that requires parameters?

A Nothing, just call it

B Provide the required arguments inside parentheses

C Declare the function again

D Use return keyword

You must provide the required arguments inside parentheses when calling a function with parameters.

What does the return keyword do in a function?

A Sends a value back to where the function was called

B Prints a message

C Stops the program

D Declares a variable

The return keyword sends a value back to the place where the function was called.

Explain how to declare and call a function in PHP with an example.

Think about the basic structure and how you use the function after declaring it.

Describe how parameters and return values work in PHP functions.

Consider how data goes into and comes out of a function.