TS.03.01 JuniorCore — asked often

Typing functions

Comes up in: Coding

This concept is being written. It gets the full five steps — explanation, predict, interview angle, practice with tests, and review cards. Here is exactly what it will cover, so you can study it elsewhere in the meantime.

What it covers

parameter and return types
optional/default/rest params
function type expressions
call signatures
this parameters
overloads (and when a union is better)

Words you will know

function typeoverloadcall signature

What you will practise

type a debounce function

Interview questions this answers

Type a function getProperty(obj, key) so the return type matches the key.
When would you use function overloads instead of a union parameter?