Q 01/05

Which company unveiled TypeScript in October 2012 after two years of internal development on the language?

A) Google

B) Microsoft

C) JetBrains

D) Facebook

Answer · why

B) Microsoft

Microsoft built the language because its own teams and its customers were struggling to write very large applications in JavaScript. The first public ...

Q 02/05

In 2025 TypeScript's team announced a port of its compiler, promising tenfold faster builds, to which language?

A) Rust

B) C++

C) Zig

D) Go

Answer · why

D) Go

Go was chosen for the native compiler, which until then had been written in TypeScript itself and run as ordinary JavaScript.

Q 03/05

What happens to the type annotations in a TypeScript program when the compiler turns it into JavaScript?

A) They become comments

B) They become runtime checks

C) They are erased

D) They are left in place

Answer · why

C) They are erased

They are erased, because type annotations are not part of JavaScript. The annotations exist only to catch mistakes before the program runs.

Q 04/05

Which editor's 1.5-million-line TypeScript codebase was checked ten times faster in early tests of the native compiler?

A) Visual Studio Code

B) JetBrains WebStorm

C) Sublime Text

D) Eclipse IDE

Answer · why

A) Visual Studio Code

Visual Studio Code is built largely in TypeScript, and a full check of it that had taken 78 seconds finished in under eight with the new compiler.

Q 05/05

Which web framework did Google rewrite from the ground up as a TypeScript-based successor to its JavaScript original?

A) Polymer

B) React

C) Angular

D) Vue.js

Answer · why

C) Angular

Angular replaced the older AngularJS, and the team dropped the JS from the name so that developers could tell the two frameworks apart.