Promises Javascript

• The Promise object represents the eventual completion (or failure) of an asynchronous operation and its resulting value.
• 3 Promise states:
  • pending: initial state, neither fulfilled nor rejected
  • fulfilled: meaning that the operation was completed successfully.
  • rejected: meaning that the operation failed.
• Promises are meant to replace callbacks

Why do we use it, what are its advantages?

• Prevents Callback Hell Javascript
• Pyramid of doom (code doesn't span horizontally)
• Promise Chaining Javascript

Polyfills

• Promise Polyfill Javascript
• Promise.all Polyfill Javascript Important

Questions

• Promises Questions Javascript

Resources

• MDN docs
• Namaste Javascript s02e02
• Roadside coder interview question