React Check if Input is Empty

<!DOCTYPE html>
<html lang="en">

<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Empty Input Check</title>
</head>

<body>
    <h1>Check if Input Field is Empty Javascript</h1>
<form>
    <label for="userInput">Enter text: </label>
    <input type="text" id="userInput" oninput="checkInput()">
    <button id="submitButton" disabled onclick="submitForm()">Submit</button>
</form>

if (userInput.trim() === '') {
                submitButton.disabled = true;
            } else {
                submitButton.disabled = false;
            }
        }

</html>

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<!DOCTYPE html>
<html lang="en">
​
<head>
    <meta charset="UTF-8">
    <meta name="viewport" content="width=device-width, initial-scale=1.0">
    <title>Empty Input Check</title>
</head>
​
<body>
    <h1>Check if Input Field is Empty Javascript</h1>
<form>
    <label for="userInput">Enter text: </label>
    <input type="text" id="userInput" oninput="checkInput()">
    <button id="submitButton" disabled onclick="submitForm()">Submit</button>
</form>
​
​
    <script>
        function checkInput() {
            var userInput = document.getElementById('userInput').value;
            var submitButton = document.getElementById('submitButton');
​
            if (userInput.trim() === '') {
                submitButton.disabled = true;
            } else {
                submitButton.disabled = false;
            }
        }
​
        function submitForm() {
            alert('Form submitted!');
            // Add your form submission logic here
        }
    </script>
    <style>
        
    
        label {
            font-size: 18px;
            margin-right: 10px;
        }
    
        input {
            padding: 8px;
            font-size: 16px;
            border: 1px solid #ccc;
            border-radius: 4px;
        }
    
        button {
            padding: 8px 16px;
            font-size: 16px;
            background-color: #4CAF50;
            color: white;
            border: none;
            border-radius: 4px;
            cursor: pointer;
        }
    
        button:disabled {
            background-color: #ccc;
            cursor: not-allowed;
        }
    </style>
</body>
​
</html>