h function for creating vnodes in Vue - Cheat Sheet & Quick Revision

Recall & Review

beginner

What is the purpose of the h function in Vue?

The h function creates virtual nodes (vnodes) that represent elements or components in Vue's virtual DOM. It helps Vue know what to render on the screen.

beginner

How do you create a simple div element with text using the h function?

Use h('div', 'Hello'). This creates a virtual div node with the text 'Hello' inside.

intermediate

What are the three main arguments of the h function?

1. Tag or component name (string or component object)<br>2. Props or attributes (object, optional)<br>3. Children (string, array, or vnode, optional)

intermediate

Can the h function create components as well as HTML elements?

Yes, you can pass a component object as the first argument to h to create a vnode for that component.

beginner

Why is the h function important in Vue's rendering process?

It builds a lightweight virtual tree of nodes that Vue compares to the real DOM. This makes updates efficient and fast.

What does the h function return in Vue?

A A string of HTML code

B A real DOM element

C A virtual node (vnode) representing an element or component

D A CSS style object

The h function returns a vnode, which is a lightweight description of what to render.

Which argument is NOT valid for the h function?

A Tag name as a string

B Props object

C Children as a string or array

D A CSS selector string

The h function does not accept CSS selector strings; it expects tag names or component objects.

How do you pass attributes like id or class using h?

A Inside the children argument

B As the second argument, an object with keys like <code>id</code> or <code>class</code>

C By adding them to the tag string

D You cannot pass attributes with <code>h</code>

Attributes are passed as an object in the second argument to h.

Can the children argument of h be an array?

A Yes, to create multiple child nodes

B No, it must be a string

C No, it must be a single vnode

D Only if the first argument is a component

Children can be an array of vnodes or strings to create multiple children.

Which Vue feature uses the h function under the hood?

A The template compiler

B Vue Router

C Vuex store

D Vue Devtools

Vue's template compiler converts templates into render functions that use h to create vnodes.

Explain how the h function helps Vue render elements and components.

Think about how Vue builds a virtual tree before showing things on the screen.

Describe the three main arguments of the h function and what each one does.

Remember the order: what to create, its properties, and its content.