Convert to hooks

src/App.js

@@ -1,15 +1,15 @@
-import React, { Component } from "react";
+import React from "react";
 import NumberGuessingGame from "./NumberGuessingGame";
 import "./App.css";
 
-class App extends Component {
-  render() {
+const App = () => {
+
     return (
       <div className="App">
         <NumberGuessingGame />
       </div>
     );
-  }
+
 }
 
 export default App;

src/Button.js

@@ -4,10 +4,12 @@ const buttonStyle = {
   minHeight: "2em",
 };
 
-export default function Button({ onClick, children }) {
+const Button = ({ onClick, children }) => {
   return (
     <button style={buttonStyle} onClick={onClick}>
       {children}
     </button>
   );
 }
+
+export default Button;

src/GameOver.js

@@ -1,6 +1,6 @@
 import Button from "./Button";
 
-function GameOver({ hasWon, onReset }) {
+const GameOver = ({ hasWon, onReset }) => {
   return (
     <div>
       {hasWon && <h2>Congratulation! You guessed my number.</h2>}

src/GuessControl.js

@@ -1,47 +1,39 @@
-import React, { Component } from "react";
+import React, { useState } from "react";
 import Button from "./Button";
 
-class GuessControl extends Component {
-  constructor(props) {
-    super(props);
-
-    this.state = {
-      currentGuess: "",
-    };
+const GuessControl = (props) => {
+   const [currentGuess, setCurrentGuess] = useState("");
+
 
     /**
      * These lines are required to make the methods/functions declared on this
      *  class have the correct `this` object when they run.
      */
-    this.handleInputChange = this.handleInputChange.bind(this);
-    this.onSubmitGuess = this.onSubmitGuess.bind(this);
-  }
-
-  handleInputChange(event) {
-    this.setState({ currentGuess: event.target.value });
-  }
+    const handleInputChange = (event) => {
+         setCurrentGuess(event.target.value);
+
+  };
 
-  onSubmitGuess() {
+  const onSubmitGuess = () => {
     // Since the values from an HTML input are strings by default,
     //  convert to a number for the returned guess value
     //  by passing in the string to the Number function.
     // See https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Number
-    this.props.onGuess(Number(this.state.currentGuess));
-    this.setState({ currentGuess: "" });
-  }
+    props.onGuess(Number(currentGuess));
+    setCurrentGuess("");
+  };
 
-  render() {
     return (
       <div>
         <input
           type="number"
-          value={this.state.currentGuess}
-          onChange={this.handleInputChange}
+          value={currentGuess}
+          onChange={handleInputChange}
         />
-        <Button onClick={this.onSubmitGuess}>Submit Guess</Button>
+        <Button onClick={onSubmitGuess}>Submit Guess</Button>
       </div>
     );
   }
-}
+
 
 export default GuessControl;

src/GuessMessage.js

@@ -1,4 +1,4 @@
-function getGuessMessage(guess, numberToGuess) {
+const getGuessMessage = (guess, numberToGuess) => {
   const distanceApart = Math.abs(numberToGuess - guess);
   if (guess < numberToGuess) {
     if (distanceApart > 10) {
@@ -15,7 +15,7 @@ function getGuessMessage(guess, numberToGuess) {
   }
 }
 
-function GuessMessage({ guess, numberToGuess, numberOfGuesses }) {
+const GuessMessage = ({ guess, numberToGuess, numberOfGuesses }) => {
   return (
     <div>
       {guess && <p>{getGuessMessage(guess, numberToGuess)}</p>}

src/NumberGuessingGame.js

@@ -1,4 +1,4 @@
-import React, { Component } from "react";
+import React, { useState } from "react";
 import GuessControl from "./GuessControl";
 import GuessMessage from "./GuessMessage";
 import GameOver from "./GameOver";
@@ -7,71 +7,57 @@ import GameOver from "./GameOver";
  *
  * Returns a random integer number from 1-100 inclusive
  */
-function getRandomNumber() {
+const getRandomNumber = () => {
   return Math.floor(Math.random() * 100) + 1;
 }
 
 const MAX_ATTEMPTS = 5;
 
-class NumberGuessingGame extends Component {
-  constructor(props) {
-    super(props);
-
-    this.state = {
-      numberToGuess: getRandomNumber(),
-      numberOfGuesses: 0,
-      latestGuess: null,
-    };
+const NumberGuessingGame = () => {
+  const [numberToGuess, setNumberToGuess] = useState(getRandomNumber());
+  const [numberOfGuesses, setNumberOfGuesses] = useState(0);
+  const [latestGuess, setLatestGuess] = useState(null) 
 
     /**
      * These lines are required to make the methods/functions declared on this
      *  class have the correct `this` object when they run.
      */
-    this.handleGuess = this.handleGuess.bind(this);
-    this.handleReset = this.handleReset.bind(this);
-  }
-
-  handleGuess(guess) {
-    this.setState({
-      latestGuess: guess,
-      numberOfGuesses: this.state.numberOfGuesses + 1,
-    });
-  }
+  const handleGuess = (guess) => {
+   setLatestGuess(guess);
+   setNumberOfGuesses(numberOfGuesses + 1);
+  };
+
 
-  handleReset() {
-    this.setState({
-      numberToGuess: getRandomNumber(),
-      numberOfGuesses: 0,
-      latestGuess: null,
-    });
-  }
+  const handleReset = () => {
+   setNumberToGuess(getRandomNumber());
+   setNumberOfGuesses(0);
+   setLatestGuess(null);
+  };
 
-  render() {
-    const isCorrectGuess = this.state.latestGuess === this.state.numberToGuess;
+    const isCorrectGuess = latestGuess === numberToGuess;
 
     const isGameOver =
-      isCorrectGuess || this.state.numberOfGuesses === MAX_ATTEMPTS;
+      isCorrectGuess || numberOfGuesses === MAX_ATTEMPTS;
 
     return (
       <div>
         <h2>I'm thinking of a number from 1 to 100.</h2>
         <h2>
           Can you guess the number I am thinking of in {MAX_ATTEMPTS} tries?
         </h2>
-        <GuessControl onGuess={this.handleGuess} />
+        <GuessControl onGuess={handleGuess} />
         {isGameOver && (
-          <GameOver hasWon={isCorrectGuess} onReset={this.handleReset} />
+          <GameOver hasWon={isCorrectGuess} onReset={handleReset} />
         )}
         {!isGameOver && (
           <GuessMessage
-            guess={this.state.latestGuess}
-            numberToGuess={this.state.numberToGuess}
-            numberOfGuesses={this.state.numberOfGuesses}
+            guess={latestGuess}
+            numberToGuess={numberToGuess}
+            numberOfGuesses={numberOfGuesses}
           />
         )}
       </div>
     );
   }
-}
 
 export default NumberGuessingGame;