PHP lesson 1: echo, strings and the PHP tag

US version. US grades and US spelling. · UK version of this lesson

PHP runs on web servers. When you open a page, the server runs the PHP and sends the RESULT – usually HTML – to your browser. Here, PHP runs inside your browser in a locked box, so you can try it safely. A complete 40-minute PHP lesson (Grades 9–12), from Unit 1: Getting started with PHP. It runs right here in your browser – nothing to install.

Time: 40 minutes + 20 min homework
Grade: Grades 9–12 (ages 14–18)
You need: A computer or tablet, paper and a pencil
Graded: Instantly, with explanations

For parents: how to use this lesson

You don't need to know PHP yourself. The lesson explains each step on screen, the way Mr Babbage, our Head of Computing, likes it: a worked example first, then a go for your child. Your child predicts what code prints, traces it and puts it in order – graded straight away – and then writes and fixes real PHP in the practice test, where it runs in the browser.

Read what your child will learn together.
Press Start the lesson below. Sit with your child for the teaching and the worked example (about 16 minutes): ask them to say what each line does.
Let them do the practice on their own, then the write-it and fix-it questions in the practice test. When code goes wrong, PHP's message is a clue – let them read it out and try again before you help.
Finish with the talk question: Why do PHP pages never show the PHP code to the visitor? Explain in one sentence.

Watch out for

echo adds a space between items. Run echo "a", "b"; – it prints ab.
Each echo starts a new line. Two echos print on one line unless you add "\n".

Miss Lovelace's tip for home: ask your child to explain one line of their program to you in their own words. If they can explain it, they understand it – and every message from PHP is a clue, not a failure.

What your child will learn

Learning goal: explain what PHP is used for on a web server.

Success looks like

I can explain what PHP is used for on a web server.
I can start a program with <?php and print text with echo.
I can end every statement with a semicolon ;.

Key words

server · PHP tag · echo · string · statement · semicolon

What to have ready

A device with a web browser (PHP runs in the browser – nothing to install)
Paper for tracing
A keyboard helps for typing code (a tablet or phone works too)

The big ideas (for the adult)

A PHP program starts with the tag <?php. Then come statements, each ending with a semicolon ;. echo "Hello"; prints Hello. The quote marks show where the text (a string) starts and ends; they are not printed.

echo prints EXACTLY what you give it – no spaces and no new lines added. echo "a", "b"; prints ab. To end a line, print "\n" (inside double quotes it means "new line").

Worked example – see it

<?php
echo "I like rice";

It prints:

I like rice

The lesson, step by step

40 minutes in 5 parts
Part	Time	How it is checked
Starter	5 min	Graded by Classfern
Teaching input	8 min	Read, watch and talk
See it, then predict	8 min	Graded by Classfern
Put it in order, trace it, check it	14 min	Graded by Classfern
Closure and exit ticket	5 min	Graded by Classfern + self-check

The lesson

It runs here on the page. No sign-up and no names – progress is kept only in this browser. Each visit picks a new mix of questions.

Homework

20 minutes: 7 questions – predict what code prints, trace it or put it in order, and check the key ideas – then a short reflection. New questions every time, all graded instantly.

Write it and fix it: practice tests

The practice tests run real PHP in your browser: write and fix short programs, graded against hidden tests.

All PHP practice tests · All 24 PHP lessons

Curriculum

CSTA K–12 Computer Science Standards (2017): 3B-AP-24 – Compare programming languages and their suitability for different problems; 3A-AP-13 – Prototype algorithms for problems drawing on prior knowledge and interests.

The standard codes are CSTA's; the descriptions are our own words.

Our lessons and questions are our own. They are not written or endorsed by any government department, testing agency or exam board. Classfern is not affiliated with or endorsed by The PHP Group. PHP runs here as php-wasm, under its open-source licences.