taizawa · October 25, 2022 01:51
diff --git a/calc_loan.html b/calc_loan.html
 <html>
    <script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
    <body>
        <form method="post">
            <p>返済回数: <input type="text" name="loan_term" value="36" /></p>
            <p>年利: <input type="text" name="interest_rate" value="2.3" /></p>

            <p>借入額: <input type="text" name="loan_amount" value="1000000" /></p>
            <p>ボーナス払い: <input type="text" name="bonus" value="300000" /></p>
            <p>ボーナス回数（一年に何回か？）: <input type="text" name="bonus_count" value="2" /></p>

            <p><input type="submit" value="計算" /></p>

            <script>

                // ExcelのPMT関数を再現
                // 金利、返済回数、借入額を指定して、毎月の返済額を計算する
                const CALC_PMT = (rate, nper, pv, fv, type) => {
                    let pmt, pvif;

                    fv || (fv = 0);
                    type || (type = 0);

                    if (rate === 0)
                    return -(pv + fv) / nper;

                    pvif = Math.pow(1 + rate, nper);
                    pmt = - rate * (pv * pvif + fv) / (pvif - 1);

                    if (type === 1)
                    pmt /= (1 + rate);
                    return pmt;
                }

                const CALC_LOAN = () => {
                    const loan_term = Number($('input[name=loan_term]').val());
                    const interest_rate = Number($('input[name=interest_rate]').val());
                    const loan_amount = Number($('input[name=loan_amount]').val());
                    const bonus = Number($('input[name=bonus]').val());
                    return CALC_PMT(interest_rate/100/12, loan_term, loan_amount-(bonus), 0, 0);
                }

                const CALC_BONUS = () => {
                    const loan_term = Number($('input[name=loan_term]').val());
                    const interest_rate = Number($('input[name=interest_rate]').val());
                    const loan_amount = Number($('input[name=loan_amount]').val());
                    const bonus = Number($('input[name=bonus]').val());
                    const bonus_count = Number($('input[name=bonus_count]').val());
                    return CALC_PMT(interest_rate/100/bonus_count, loan_term/12*bonus_count, bonus, 0, 0);
                }

                $('input[type=submit]').click((e) => {
                    e.preventDefault();

                    const loan_term = Number($('input[name=loan_term]').val());
                    const interest_rate = Number($('input[name=interest_rate]').val());
                    const loan_amount = Number($('input[name=loan_amount]').val());
                    const bonus = Number($('input[name=bonus]').val());
                    const bonus_count = Number($('input[name=bonus_count]').val());

                    // 毎月の返済額
                    const monthly_payment = Math.floor(Math.abs(CALC_LOAN()));
                    // ボーナス時の加算額
                    const bonus_payment = bonus_count && bonus ? Math.floor(Math.abs(CALC_BONUS())) : 0;
                    // 総支払額
                    const total_payment = bonus_count && bonus ? 
                        Math.floor(monthly_payment * loan_term + bonus_payment * loan_term/12*bonus_count)
                        : Math.floor(monthly_payment * loan_term);

                    $('body').append('<p>毎月の返済額: ' + monthly_payment + '</p>');
                    $('body').append('<p>ボーナス時の加算額: ' + bonus_payment + '</p>');
                    $('body').append('<p>総支払額: ' + total_payment + '</p>');

                    return false;
                });

            </script>
        </form>
    </body>
 </html>
	<html>
	<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
	<body>
	<form method="post">
	<p>返済回数: <input type="text" name="loan_term" value="36" /></p>
	<p>年利: <input type="text" name="interest_rate" value="2.3" /></p>

	<p>借入額: <input type="text" name="loan_amount" value="1000000" /></p>
	<p>ボーナス払い: <input type="text" name="bonus" value="300000" /></p>
	<p>ボーナス回数（一年に何回か？）: <input type="text" name="bonus_count" value="2" /></p>

	<p><input type="submit" value="計算" /></p>

	<script>

	// ExcelのPMT関数を再現
	// 金利、返済回数、借入額を指定して、毎月の返済額を計算する
	const CALC_PMT = (rate, nper, pv, fv, type) => {
	let pmt, pvif;

	fv \|\| (fv = 0);
	type \|\| (type = 0);

	if (rate === 0)
	return -(pv + fv) / nper;

	pvif = Math.pow(1 + rate, nper);
	pmt = - rate * (pv * pvif + fv) / (pvif - 1);

	if (type === 1)
	pmt /= (1 + rate);
	return pmt;
	}

	const CALC_LOAN = () => {
	const loan_term = Number($('input[name=loan_term]').val());
	const interest_rate = Number($('input[name=interest_rate]').val());
	const loan_amount = Number($('input[name=loan_amount]').val());
	const bonus = Number($('input[name=bonus]').val());
	return CALC_PMT(interest_rate/100/12, loan_term, loan_amount-(bonus), 0, 0);
	}

	const CALC_BONUS = () => {
	const loan_term = Number($('input[name=loan_term]').val());
	const interest_rate = Number($('input[name=interest_rate]').val());
	const loan_amount = Number($('input[name=loan_amount]').val());
	const bonus = Number($('input[name=bonus]').val());
	const bonus_count = Number($('input[name=bonus_count]').val());
	return CALC_PMT(interest_rate/100/bonus_count, loan_term/12*bonus_count, bonus, 0, 0);
	}

	$('input[type=submit]').click((e) => {
	e.preventDefault();

	const loan_term = Number($('input[name=loan_term]').val());
	const interest_rate = Number($('input[name=interest_rate]').val());
	const loan_amount = Number($('input[name=loan_amount]').val());
	const bonus = Number($('input[name=bonus]').val());
	const bonus_count = Number($('input[name=bonus_count]').val());

	// 毎月の返済額
	const monthly_payment = Math.floor(Math.abs(CALC_LOAN()));
	// ボーナス時の加算額
	const bonus_payment = bonus_count && bonus ? Math.floor(Math.abs(CALC_BONUS())) : 0;
	// 総支払額
	const total_payment = bonus_count && bonus ?
	Math.floor(monthly_payment * loan_term + bonus_payment * loan_term/12*bonus_count)
	: Math.floor(monthly_payment * loan_term);

	$('body').append('<p>毎月の返済額: ' + monthly_payment + '</p>');
	$('body').append('<p>ボーナス時の加算額: ' + bonus_payment + '</p>');
	$('body').append('<p>総支払額: ' + total_payment + '</p>');

	return false;
	});

	</script>
	</form>
	</body>
	</html>