RxJS

[justinbmeyer]

card number

• Use new BehaviorSubject("") to avoid undefined

card-error

• undefined if there is no error
• validateCard should be in "How to solve this problem" section

[tehfedaykin]

debugging

• log example incorrect
• final solution is missing error message in html

[justinbmeyer]

Error on blur

• [ ] link to operators merge, scan, etc

[tehfedaykin]

Disable Pay Button

• [ ] should write isCardInvalid function that uses combineLatest

[tehfedaykin]

Show Paying

• [ ] const letters = concat(first, last) is incorrect

[justinbmeyer]

multi-cast observables are not always observable by angular: https://codepen.io/vijain/pen/MLrajr?editors=0011

disable: shows nothing