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Lära Defining and Calling Functions | Getting Started with PHP Functions
PHP Functions

bookDefining and Calling Functions

How to Define a Function

To define a function in PHP, use the function keyword, followed by the function name and a pair of parentheses. The code you want the function to run goes inside curly braces. Here’s the basic structure:

function functionName() {
    // Code to run when the function is called
}

Example:

function sayHello() {
    echo "Hello, world!";
}

This defines a function named sayHello that prints "Hello, world!" when it is called.

How to Call a Function

To use your function, write its name followed by parentheses:

sayHello();

This line runs the code inside the sayHello function, so you will see Hello, world! printed on the screen.

Key Points

  • Always start a function definition with the function keyword;
  • Function names should be descriptive and use only letters, numbers, and underscores;
  • Don't forget the parentheses, even if your function does not take any input;
  • Call a function by writing its name followed by parentheses.

By defining and calling functions, you can make your PHP programs more organized and efficient.

functions_example.php

functions_example.php

copy
123456789101112131415
<?php // Define a function named 'addNumbers' that takes two arguments function addNumbers($a, $b) { // Calculate the sum of the two arguments $sum = $a + $b; // Return the result to the caller return $sum; } // Call the 'addNumbers' function with 5 and 7 as arguments $result = addNumbers(5, 7); // Print the returned value to the screen echo "The sum of 5 and 7 is: " . $result;
question mark

Which of the following is the correct way to define a simple function named greet in PHP?

Select the correct answer

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 2

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bookDefining and Calling Functions

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How to Define a Function

To define a function in PHP, use the function keyword, followed by the function name and a pair of parentheses. The code you want the function to run goes inside curly braces. Here’s the basic structure:

function functionName() {
    // Code to run when the function is called
}

Example:

function sayHello() {
    echo "Hello, world!";
}

This defines a function named sayHello that prints "Hello, world!" when it is called.

How to Call a Function

To use your function, write its name followed by parentheses:

sayHello();

This line runs the code inside the sayHello function, so you will see Hello, world! printed on the screen.

Key Points

  • Always start a function definition with the function keyword;
  • Function names should be descriptive and use only letters, numbers, and underscores;
  • Don't forget the parentheses, even if your function does not take any input;
  • Call a function by writing its name followed by parentheses.

By defining and calling functions, you can make your PHP programs more organized and efficient.

functions_example.php

functions_example.php

copy
123456789101112131415
<?php // Define a function named 'addNumbers' that takes two arguments function addNumbers($a, $b) { // Calculate the sum of the two arguments $sum = $a + $b; // Return the result to the caller return $sum; } // Call the 'addNumbers' function with 5 and 7 as arguments $result = addNumbers(5, 7); // Print the returned value to the screen echo "The sum of 5 and 7 is: " . $result;
question mark

Which of the following is the correct way to define a simple function named greet in PHP?

Select the correct answer

Var allt tydligt?

Hur kan vi förbättra det?

Tack för dina kommentarer!

Avsnitt 1. Kapitel 2
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