Computed with getter and setter in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is a computed property in Vue?

A computed property is a special reactive value that automatically updates when its dependencies change. It is used to calculate values based on other data in a Vue component.

intermediate

How does a computed property with a getter and setter work in Vue?

It has two parts: a getter to return a value based on reactive data, and a setter to update reactive data when the computed property is changed.

intermediate

Why use a setter in a computed property?

A setter lets you react to changes when someone modifies the computed property, allowing you to update the underlying data accordingly.

beginner

Show a simple example of a computed property with getter and setter in Vue.

Example:
const fullName = computed({
  get() { return firstName.value + ' ' + lastName.value },
  set(value) {
    const parts = value.split(' ')
    firstName.value = parts[0]
    lastName.value = parts.slice(1).join(' ') || ''
  }
})

beginner

What happens if you only provide a getter in a computed property?

The computed property becomes read-only. You cannot assign a new value to it because there is no setter to handle changes.

What does the setter in a Vue computed property do?

A Prevents changes to the computed property

B Updates the underlying reactive data when the computed property is assigned a new value

C Returns the computed value based on reactive data

D Triggers a lifecycle hook

The setter updates the reactive data when you assign a new value to the computed property.

If a computed property has only a getter, what is true?

A It does not update when dependencies change

B It can be assigned new values

C It is read-only

D It requires a setter to work

Without a setter, the computed property is read-only and cannot be assigned new values.

Which Vue API is used to create a computed property with getter and setter?

A computed()

B ref()

C watch()

D reactive()

The computed() function creates computed properties with optional getter and setter.

What is a common use case for a computed property with a setter?

A To format and update multiple reactive values together

B To display static text

C To fetch data from an API

D To define component props

Setters let you update multiple reactive values when the computed property changes, like splitting a full name into first and last names.

In Vue, what happens when dependencies of a computed property change?

A Nothing happens until manually triggered

B The setter is called

C The component reloads

D The computed property automatically recalculates

Computed properties automatically recalculate when their reactive dependencies change.

Explain how a computed property with getter and setter works in Vue and why it is useful.

Think about how you can both read and write a computed value.

Describe a real-life example where a computed property with getter and setter would help manage data in a Vue component.

Imagine editing a full name input that updates separate fields.