React - useRef

Question 1

What are the 2 rules to remember about references?

Answer 1

1. The value of the reference is persisted (stays the same) between component re-renderings;
2. Updating a reference doesn’t trigger a component re-rendering.

Question 2

How many arguments does useRef( ) accept?

Answer 2

one argument, the references initial value.

Question 3

What special property does a reference have ?

Answer 3

The “current” property.

reference.current accesses the reference value, and reference.current = newValue updates the reference value.

Question 4

What are the 2 main differences between references and state?

Answer 4

1. Updating a reference doesn’t trigger re-rendering, while updating the state makes the component re-render.
2. The reference update is synchronous (the updated reference value is available right away), while the state update is asynchronous (the state variable is updated after re-rendering).

Question 5

Are reference updates asynchronous?

Answer 5

No they are synchronous, their new value can be accessed straight away.