js函数不返回onclick

Question

我创建了一个无法使用 onclick return 访问的函数。

我确定这是我所缺少的简单东西。

HTML:

<html>
<head>
<script type="text/javascript" src="http://code.jquery.com/jquery-latest.js"></script>
<script type="text/javascript" src="schedule.js"></script>
</head>
<body>

     <input type="button" onclick="computeSchedule();" value="Submit" /><br>
     <p id="scheduleOutput"></p>

</body>
</html>

JS:

function computeSchedule(loan_amount, interest_rate, payments_per_year, years, payment) {
var schedule = [];
var remaining = loan_amount;
var number_of_payments = payments_per_year * years;

for (var i=0; i<=number_of_payments; i++) {
    var interest = remaining * (interest_rate/100/payments_per_year);
    var principle = (payment-interest);
    var row = [i, principle>0?principle:0, interest>0?interest:0, remaining>0?remaining:0];
    schedule.push(row);
    remaining -= principle
}

return schedule;
}

var list = JSON.stringify(computeSchedule(100000, 0.005, 12, 15, 843.86), 0, 4)

document.getElementById('scheduleOutput').innerHTML = list;

我可以在 jsFiddle onload, but when I change js settings to "no wrap - in head" 中自动获取 return 的功能，但它不起作用。当我尝试在 jsFiddle 之外运行?

时，我假设正在发生的事情也会发生

Answer 1

当您单击按钮时，函数 computeSchedule() 将被触发，但没有任何值被传递给它。我敢打赌，如果您将值放在 html 行的参数中，它就会起作用。

<input type="button" onclick="computeSchedule(100000, 0.005, 12, 15, 843.86);" value="Submit" />

Answer 2

您在正文内容准备就绪之前就已经编写了运行秒。这就是为什么 document.getElementById 似乎不起作用，因为此时不存在这样的元素。

尝试将您的代码包装在简单的 "content load" 侦听器中，以确保在所有元素准备就绪后它将运行：

document.addEventListener('DOMContentLoaded', function() {
    function computeSchedule(loan_amount, interest_rate, payments_per_year, years, payment) {
        var schedule = [];
        var remaining = loan_amount;
        var number_of_payments = payments_per_year * years;

        for (var i=0; i<=number_of_payments; i++) {
            var interest = remaining * (interest_rate/100/payments_per_year);
            var principle = (payment-interest);
            var row = [i, principle>0?principle:0, interest>0?interest:0, remaining>0?remaining:0];
            schedule.push(row);
            remaining -= principle
        }

        return schedule;
    }

    var list = JSON.stringify(computeSchedule(100000, 0.005, 12, 15, 843.86), 0, 4)

    document.getElementById('scheduleOutput').innerHTML = list;
});

是的，您的 onclick 现在没有向该函数传递任何数据。因此，您还需要将参数传递给它，一切都应该正常工作。

js函数不返回onclick

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