CodeLab

Learn by reading real code

Examples and small projects from our lessons. Read the explanation, copy or download the code, run front-end examples live, and experiment in the Playground.

8Examples

2Projects

6Languages

6Live previews

playground.js

const learner = { name: 'You', level: 'beginner' };

function practise(topic) {
  console.log(`${learner.name} is learning ${topic}!`);
  learner.level = 'getting better';
}

['HTML', 'CSS', 'JavaScript'].forEach(practise);

Open the PlaygroundWrite HTML, CSS & JavaScript and see it run

Results 1

Any level Beginner Intermediate Advanced

Queries Intermediate Clear all

database.sql

SELECT c.title           AS course,
       COUNT(a.id)       AS attempts,
       ROUND(AVG(a.score), 1) AS average_score
FROM courses c
JOIN quiz_attempts a ON a.course_id = c.id
WHERE a.status = 'submitted'
GROUP BY c.id, c.title

Intermediate Code only

Average quiz score per course with JOIN and GROUP BY

Combine two tables and summarise the results.

SQL / MySQL

9 lines View snippet