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What is conditional rendering?

Learn that you can show different content based on a condition.

What is conditional rendering?

Conditional rendering shows different content based on a condition. For example, showing Dashboard when the user is logged in and Login when not.

React offers several ways: the if statement, the ternary operator cond ? a : b, the logical AND &&, and early return. Each fits a different situation.

The rule: the value returned by the condition is either valid JSX or null, false, undefined (React renders none of these).

Conditional render approaches

Three common approaches exist. First, ternary: { 'isLoggedIn ? <Dashboard /> : <Login />' }. Ideal for choosing between two options.

Second, logical AND: { 'hasError && <Error />' }. Ideal for showing something only when a condition holds.

Third, early return: at the top of the component, if (!user) return null;. Improves readability for complex conditions.

Practice Banner by login state

Complete the skeleton. Write a component called Banner that takes ({ '{ isLoggedIn }' }) as parameter. If isLoggedIn is true, return <p>Welcome</p>; otherwise <p>Please log in</p> (use ternary). Don't forget to export.

Starter code

App.jsx
// Write the Banner component here

Sample solution

App.jsx
function Banner({ isLoggedIn }) {
  return isLoggedIn ? <p>Welcome</p> : <p>Please log in</p>;
}

export default Banner;

Questions and answers

Review the lesson questions together with their answers. To test yourself, solve the lesson interactively.

1 What does conditional rendering do?

  • Shows different content based on a condition Correct answer
  • Changes styling
  • Stores state
  • Updates DOM

Explanation: Conditional rendering shows content based on a condition.

2 Conditional render syntax

Question 
Condition ____ ? a : b.
Answer 
Condition ? ? a : b.

Explanation: ? is the ternary operator.

3 Match the approaches

Term Meaning
cond ? a : b Ternary
cond && a Logical AND
if (x) return Early return
null Not rendered

All lessons in Beginner

1 React intro

  1. What is React?
  2. Setup and Vite
  3. Your first component
  4. Summary - React intro

2 JSX basics

  1. What is JSX?
  2. Expressions and curly braces
  3. Attributes and className
  4. Summary - JSX basics

3 Components

  1. Component logic
  2. Component tree
  3. Naming rules
  4. Summary - Components

4 Profile card

  1. Project: Profile card
  2. Avatar component
  3. Info list
  4. Assemble the card

5 Props

  1. What are props?
  2. Reading props
  3. Children prop
  4. Default props
  5. Summary - Props

6 Conditional rendering

  1. What is conditional rendering?
  2. Ternary operator
  3. Logical AND (&&)
  4. Early return
  5. Summary - Conditional rendering

7 List rendering

  1. What is list rendering?
  2. The key attribute
  3. Array to components
  4. Filtering and sorting
  5. Summary - List rendering

8 Shopping list

  1. Project: Shopping list
  2. Item component
  3. List body
  4. Empty state

9 Events

  1. Events
  2. The event object
  3. Form events
  4. Summary - Events

10 useState

  1. What is state?
  2. The useState call
  3. Updating state
  4. Multiple state values
  5. Summary - useState

11 Counter app

  1. Project: Counter app
  2. Number and buttons
  3. Decrement and reset
  4. Boundary control

12 Forms

  1. Controlled input
  2. Form submission
  3. Multiple fields
  4. Summary - Forms

13 Styling

  1. Styling with CSS
  2. CSS Modules
  3. Inline styles
  4. Summary - Styling

14 styled-components

  1. What is styled-components?
  2. Styling with props
  3. Using themes
  4. Summary - styled-components

15 useReducer

  1. What is useReducer?
  2. Action and state
  3. useState vs useReducer
  4. Summary - useReducer

16 useEffect

  1. What is useEffect?
  2. Dependency array
  3. Cleanup function
  4. Summary - useEffect

17 Context

  1. What is context?
  2. createContext
  3. Provider and useContext
  4. Summary - Context

18 useRef

  1. What is useRef?
  2. DOM access
  3. Timer example
  4. Summary - useRef

19 Todo app

  1. Project: Todo app
  2. Todo entry form
  3. Todo list
  4. Filter and summary

20 Beginner final

  1. Challenge: Weather card
  2. Challenge: Cart summary
  3. Challenge: Counter and reset
  4. Challenge: Dropdown menu