<EditText
    android:inputType="numberDecimal"
    android:digits="0123456789"
    android:maxLength="15"
    android:layout_width="match_parent"
    android:layout_height="wrap_content"
    android:hint="Enter amount"
    android:id="@+id/et_amount" />

String amount = et_amount.getText().toString();
if (!TextUtils.isEmpty(amount)) {
    // Format and display the amount
    DecimalFormat formatter = new DecimalFormat();
    formatter.setMaximumFractionDigits(2);
    formatter.setMinimumFractionDigits(0);
    formatter.setGroupingUsed(false);
    String formattedAmount = formatter.format(Double.parseDouble(amount));
    et_amount.setText(formattedAmount);
}

<div id="amount-input">
    <input type="text" id="amount" placeholder="Enter amount" />
    <button id="submit-btn">Submit</button>
</div>

<script>
    // Get the HTML elements
    const amountInput = document.getElementById('amount-input');
    const amount = document.getElementById('amount');
    const submitBtn = document.getElementById('submit-btn');

    // Format and display the amount
    const formatAmount = (amount) => {
        const formatter = new Intl.NumberFormat('en-US', {
            minimumFractionDigits: 2,
            maximumFractionDigits: 2
        });
        return formatter.format(amount);
    };

    amount.value = formatAmount(amount.value);

    // Handle the submit button click event
    submitBtn.addEventListener('click', () => {
        // Format and display the amount
        amount.value = formatAmount(amount.value);
    });
</script>

def test_format_amount(self):

    self.assertEqual(format_amount(1000), 'USD $1.00')

    self.assertEqual(format_amount(1000000), 'USD $1000.00')

    self.assertEqual(format_amount(1000000000), 'USD $1,000,000.00')

    self.assertEqual(format_amount(1000000000000), 'USD $10,000,000.00')

    self.assertEqual(format_amount(1000000000000000), 'USD $100,000,000.00')

    self.assertEqual(format_amount(1000000000000000000), 'USD $1,000,000,000.00')

    self.assertEqual(format_amount(0.00000000), 'USD $0.00')

    self.assertEqual(format_amount(0.0000000000), 'USD $0.00')

    self.assertEqual(format_amount(0.00000000000), 'USD $0.00')

    self.assertEqual(format_amount(0.000000000000), 'USD $0.00')

    self.assertEqual(format_amount(0.000000000000