Your first PHP script

The opening tag

PHP code lives inside files with the php extension, and the engine only runs what sits between <?php and ?>. Everything outside the tag is sent to the visitor unchanged.

<?php echo "Hello, world!";

echo prints strings

echo prints text to the output. Give it a string in quotes and end the line with a semicolon:

echo "Hello, world!"; // Hello, world! echo "Second line"; // Second line

Run it in the terminal

Save the two lines above as hello.php and run the file with the php command:

Run the script

php hello.php

The terminal prints Hello, world! and nothing else. No server and no browser are needed for plain scripts like this one.

Common beginner mistakes

Three mistakes catch almost every beginner. First, a missing semicolon stops the whole file. Second, code written without the <?php tag never runs: the server sends it back as plain text.

Third, an unclosed quote swallows the rest of the file, so close each string on the same line you open it:

echo "Quotes come in pairs: open and close on one line";

Next: Comments in PHP

Автор статьи: Arthur Isaev