read04.md

Forms in React App

- In HTML, form elements such as (input) and (select) maintain their own state and update it based on user input.

- On the other hand , In React, mutable state is kept in the state property of components, and only updated with setState().

- controlled component is an input form element whose value is controlled by React in a way that combine the HTML form elements and the React mutable state's by making the React state be the “single source of truth”.

The React component that renders a form also controls what happens in that form on subsequent user input.

The Conditional (Ternary) Operator

- Its mean that we can our if statment Shorter by writeing it in one but in easier different way .

- For Example:

- The following syntax is a typical if statement:

if ( condition ) {
  value if true;
} else {
  value if false;
}

- In the ternary operator , the above if statment syntax can be rewrote by the following way:

condition ? value if true : value if false

Here’s what you need to know:

1. The condition is what you’re actually testing. The result of your condition should be true or false or at least coerce to either boolean value.

2. A ? separates our conditional from our true value. Anything between the ? and the : is what is executed if the condition evaluates to true.

3. Finally a : colon. If your condition evaluates to false, any code after the colon is executed.