Promise: the API

Promise API overview

• new Promise() requires a function as param

resolving a promise

• via constructor parameter new Promise((resolve) => { resolve(); })
• using Promise.resolve()

a rejected promise

• using the constructor parameter
• via Promise.reject()

Promise.all()

• Promise.all([p1, p2]) resolves when all promises resolve
• Promise.all([p1, p2]) rejects when a promise is rejected

Promise.race()

• Promise.race([p1, p2]) resolves/reject when one of the promises resolves/rejects
• Promise.race([p1, p2]) rejects when one of the promises rejects
• Promise.race([p1, p2]) order matters (and timing)