Added question 323. What is the difference between Imperative and Declarative in React?

README.md

@@ -336,7 +336,8 @@
 |320| [What is the difference between async mode and concurrent mode?](#what-is-the-difference-between-async-mode-and-concurrent-mode)|
 |321| [Can I use javascript urls in react16.9?](#can-i-use-javascript-urls-in-react16.9)|
 |322| [What is the purpose of eslint plugin for hooks?](#what-is-the-purpose-of-eslint-plugin-for-hooks)|
-|323| [?](#)|
+|323| [What is the difference between Imperative and Declarative in React?](#what-is-the-difference-between-imperative-and-declarative-in-react)|
+|324| (#) ?
 
 ## Core React
 
@@ -6261,5 +6262,33 @@
 
    **[⬆ Back to Top](#table-of-contents)**
 
-323. ### ?
-
+323. ### What is the difference between Imperative and Declarative in React?
+Imagine a simple UI component, such as a "Like" button. When you tap it, it turns blue if it was previously grey, and grey if it was previously blue.
+
+The imperative way of doing this would be:
+
+            ```javascript
+            if( user.likes() ) {
+                if( hasBlue() ) {
+                    removeBlue();
+                    addGrey();
+                } else {
+                    removeGrey();
+                    addBlue();
+                }
+            }```
+Basically, you have to check what is currently on the screen and handle all the changes necessary to redraw it with the current state, including undoing the changes from the previous state. You can imagine how complex this could be in a real-world scenario.
+
+In contrast, the declarative approach would be:
+
+            ```javascript
+            if( this.state.liked ) {
+                return <blueLike />;
+            } else {
+                return <greyLike />;
+            }```
+Because the declarative approach separates concerns, this part of it only needs to handle how the UI should look in a sepecific state, and is therefore much simpler to understand.
+
+   **[⬆ Back to Top](#table-of-contents)**
+
+324. ### ?