NG Interview Set I - Pipes Questions

Question 1

What is a pure pipe?

Answer 1

• A pipe that is only executed when Angular detects a pure change to the input value (e.g. new primitive object or new object reference)

Question 2

What is an impure pipe?

Answer 2

• A pipe that is executed during every component change detection cycle (i.e., often – every keystroke, mouse move)

Question 3

What is an async pipe?

Answer 3

• An impure pipe that accepts a promise or observable as input and eventually returns emitted values

Question 4

What kind of data can be used with async pipe?

Answer 4

• Stateful, asynchronous

Question 5

What types of pipes are supported in Angular 2?

Answer 5

• Pure and impure pipes (async pipes are a kind of impure pipe)