Understand the technologies you use.
Learn
Work through a lesson, practise aptitude questions, or look up a word.
- Regular expressionsRead a pattern someone else wrote, and write one that does what you meant. 4 lessons.Works offline
- SQLRead a query someone else wrote, and write one that answers the question you were asked. 4 lessons.Works offline
- GitUnderstand what a commit really is, and get yourself out of the states that usually cause panic. 4 lessons.Works offline
- HTTP and the webRead a request and a response, and know which part of them you can trust. 4 lessons.Works offline
- JSON and data formatsKnow what a format can hold, and stop losing data in the gaps between them. 4 lessons.Works offline
- DictionaryMeanings, parts of speech and examples for English words.Saved for offline
- BooksSearch millions of books, browse shelves and find classics you can read free.Saved for offline
Aptitude practice
Ten questions a set, as many sets as you like. The computer picks the numbers and works out every answer, so none of them is from a real examination — and the key cannot be wrong.
- PercentagesPercent of, percent change, successive discounts
- Profit and lossCost, selling and marked price, discounts
- Simple interestInterest, rate and time
- Compound interestTwo- and three-year compounding, CI − SI
- Time and workWorking together, pipes and cisterns
- Ratio and proportionDividing amounts, changing ratios
- Speed, time and distanceAverage speed, trains
- AveragesAverage of a set, adding or removing a value