developed & maintained by Microsoft • strict syntactical superset of JavaScript • eases development of large scale applications written in JavaScript • extends JavaScript by adding static types, classes, modules, interfaces & generics 5 years old
program 2. Not able to fully infer the type of a particular variable and warns against using it as is 3. Even if your source code has TypeScript errors, it will still produce JavaScript code which you can execute Spell Checker
easily ✓ non-invasive ✓ long-term vision ✓ clean output To Type or Not To Type Pros of JavaScript • EVERYWHERE • awesome libraries • flexible Cons of JavaScript • dynamic typing • lack of modularity • verbose patterns