Add Two Numbers in React Js

<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.development.js"></script>

  <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState } = React;
    function App() {
     // Step 1: Create a state variable for numbers
      const [numbers, setNumbers] = useState({
        num1: 34,
        num2: 45,
        num3: 67,
      });

const { num1, num2, num3 } = numbers;

// Step 2: Create a state variable for the sum
      const [sum, setSum] = useState(0);

// Step 3: Create a function to handle input changes
      const handleNumChange = (e, fieldName) => {
        const newValue = parseInt(e.target.value, 10);
        setNumbers({ ...numbers, [fieldName]: newValue });
      };

// Step 4: Calculate the sum
      const calculateSum = () => {
        const result = num1 + num2 + num3;
        setSum(result);
      };

return (
        <div className='container'>
          <h1 className='title'>React Js Add Three Numbers</h1>
          <input type="number" className='input' placeholder="Number 1" value={num1}   onChange={(e) => handleNumChange(e, 'num1')} />
          <input type="number" className='input' placeholder="Number 2" value={num2}   onChange={(e) => handleNumChange(e, 'num2')} />
          <input type="number" className='input' placeholder="Number 3" value={num3}   onChange={(e) => handleNumChange(e, 'num3')} />
          <button className='calculate-button' onClick={calculateSum}>Calculate Sum</button>
          <p className='sum-text'>Sum: {sum}</p>
        </div>

);
    }
    ReactDOM.render(<App />, document.getElementById('app'));
  </script>
  <style>
    .container {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      margin: 0 auto;
      width: 500px;
      text-align: center;
      box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12),
        0 2px 4px 0 rgba(0, 0, 0, 0.24);
      padding: 20px;
      font-family: Arial, sans-serif;
    }

.title {
      font-size: 24px;
      margin-bottom: 20px;
      color: #333;
    }

.input {
      width: 200px;
      padding: 10px;
      margin: 5px;
      border: 1px solid #ccc;
      border-radius: 5px;
      font-size: 16px;
      outline: none;
    }

.calculate-button {
      padding: 10px 20px;
      background-color: #007bff;
      color: white;
      border: none;
      border-radius: 5px;
      font-size: 16px;
      cursor: pointer;
      transition: background-color 0.3s ease;
    }

.calculate-button:hover {
      background-color: #0056b3;
    }

.sum-text {
      font-size: 18px;
      margin-top: 20px;
      color: #333;
    }
  </style>
</body>

</html>

 
<!DOCTYPE html>
<html>
<head>
  <meta charset="UTF-8">
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react/17.0.2/umd/react.development.js"></script>
  <script src="https://cdnjs.cloudflare.com/ajax/libs/react-dom/17.0.2/umd/react-dom.development.js"></script>
<!-- This is used to compile on runtime -->
  <script src="https://cdnjs.cloudflare.com/ajax/libs/babel-standalone/6.26.0/babel.min.js"></script>
</head>
<body>
  <div id="app"></div>
  <script type="text/babel">
    const { useState } = React;
    function App() {
     // Step 1: Create a state variable for numbers
      const [numbers, setNumbers] = useState({
        num1: 34,
        num2: 45,
        num3: 67,
      });
​
      const { num1, num2, num3 } = numbers;
​
      // Step 2: Create a state variable for the sum
      const [sum, setSum] = useState(0);
​
      // Step 3: Create a function to handle input changes
      const handleNumChange = (e, fieldName) => {
        const newValue = parseInt(e.target.value, 10);
        setNumbers({ ...numbers, [fieldName]: newValue });
      };
​
      // Step 4: Calculate the sum
      const calculateSum = () => {
        const result = num1 + num2 + num3;
        setSum(result);
      };
​
      return (
        <div className='container'>
          <h1 className='title'>React Js Add Three Numbers</h1>
          <input type="number" className='input' placeholder="Number 1" value={num1}   onChange={(e) => handleNumChange(e, 'num1')} />
          <input type="number" className='input' placeholder="Number 2" value={num2}   onChange={(e) => handleNumChange(e, 'num2')} />
          <input type="number" className='input' placeholder="Number 3" value={num3}   onChange={(e) => handleNumChange(e, 'num3')} />
          <button className='calculate-button' onClick={calculateSum}>Calculate Sum</button>
          <p className='sum-text'>Sum: {sum}</p>
        </div>
​
      );
    }
    ReactDOM.render(<App />, document.getElementById('app'));
  </script>
  <style>
    .container {
      display: flex;
      flex-direction: column;
      align-items: center;
      justify-content: center;
      margin: 0 auto;
      width: 500px;
      text-align: center;
      box-shadow: 0 1px 2px 0 rgba(0, 0, 0, 0.12),
        0 2px 4px 0 rgba(0, 0, 0, 0.24);
      padding: 20px;
      font-family: Arial, sans-serif;
    }
​
    .title {
      font-size: 24px;
      margin-bottom: 20px;
      color: #333;
    }
​
    .input {
      width: 200px;
      padding: 10px;
      margin: 5px;
      border: 1px solid #ccc;
      border-radius: 5px;
      font-size: 16px;
      outline: none;
    }
​
    .calculate-button {
      padding: 10px 20px;
      background-color: #007bff;
      color: white;
      border: none;
      border-radius: 5px;
      font-size: 16px;
      cursor: pointer;
      transition: background-color 0.3s ease;
    }
​
    .calculate-button:hover {
      background-color: #0056b3;
    }
​
    .sum-text {
      font-size: 18px;
      margin-top: 20px;
      color: #333;
    }
  </style>
</body>
​
</html>