Creating and Running .php Files

Write your PHP code in a text editor and save the file with a .php extension. Save the file using the UTF-8 character encoding.

PHP code must always start with the <?php tag. The closing ?> tag at the end of the file can be omitted (omitting it is recommended for PHP-only files).

sample_hello.php

<?php

$name = 'Tsunemori Akane';
$age = 21;

echo 'Name: ' . $name . "\n";
echo 'Age: ' . $age . "\n";

if ($age >= 20) {
    echo "Adult.\n";
} else {
    echo "Minor.\n";
}

Write PHP code after the <?php tag like this.

You can write comments (notes) in a .php file. Comments are ignored by the PHP interpreter, so they are useful for leaving descriptions or notes about the code.

<?php

// A script that displays user information.
# Shell script-style single-line comments also work.

function greet($name, $age) {
    // Receives name and age as arguments and displays the information.
    echo 'Name: ' . $name . "\n";
    echo 'Age: ' . $age . "\n";
}

greet('Kogami Shinya', 30);

// is commonly used for single-line comments. # is a notation from shell scripts that also works in PHP, but // is the standard in modern PHP.

Open a terminal (macOS / Linux) or command prompt (Windows), navigate to the directory where the .php file is saved, then run it.

php hello.php

Name: Tsunemori Akane
Age: 21
Adult.

If PHP is not installed, see Setup.

When running PHP via a web server (Apache, Nginx, etc.), place the .php file in the document root and access it with a browser. Unlike command-line execution, the main use case here is to output HTML and display it as a web page.

A .php file is simply a plain text file. You can create one by writing PHP code in a text editor and saving it with a .php extension. No special tools are needed.

PHP code must always start with the <?php tag. To run from the command line, use php filename.php; to run via a web server, access it with a browser.

Three types of comments are available: //, #, and /* */. // is most commonly used for single-line comments.

For recommended editors and PHP installation instructions, see Setup.