保存购买日期并为其添加 X 时间 [重复]

Question

我正在创建一个节点应用程序，用户可以使用以下 HTML 输入选择 bought 日期：<input placeholder="Date Bought" class="textbox-n form-control" type="text" onfocus="(this.type='date')" onblur="(this.type='text')" id="bought" name="bought">

然后使用 var bought = req.body.bought; 将其存储到 mongodb 中，并且用户将几个月输入到另一个具有 name="warranty" 的 HTML 输入中，我需要使用 bought 日期和 warranty 月份转换为日期.我怎样才能添加这些？我试过这个：

  var bought = req.body.bought;
  var warrantyMonths = req.body.warranty;
  var warranty = bought.setMonth(bought.getMonth()+ warrantyMonths); 

据此guide

Answer 1

尝试使用Moment.js

如果保修月份是整数，您可以：

var bought = moment(req.body.bought);
var warrantyMonths = req.body.warranty;
var warranty = moment(bought).add(warrantyMonths, "month");

Moment 只是 JS 日期对象的包装器，因此它无缝且易于使用。您可以将其安装为 npm 包，将其导入您的页面，并将其传递给不同格式的日期字符串（请参阅文档）或任何有效的 javascript 日期对象。我不能再无时间处理日期了，imo 它应该是标准库的一部分。

Answer 2

查看代码和 cmets 以了解您的代码无法正常工作的原因

function calculateWarranty() {
  // get the date text and convert into date Object
  var bought = new Date(document.getElementById('bought').value);
  // get the number of warranty months and convert to integer (second arguments ensures that the integer is base 10)
  // if you do not convert the number, it will do String concatenation while calling dateObj.setMonth(getMonth_int + warrant_string )
  // for example: 2017-10-21 will give bought.getMonth() === 9 + "1", which will equal 91 instead of 10
  var warrantyMonths = parseInt(document.getElementById('warranty').value, 10);

  // display in console for debugging
  console.log(bought);
  console.log(warrantyMonths);

  var boughtMonth = bought.getMonth();

  // add bought month and warranty month (both should be integer as stated earlier)
  var warrantyMonth = boughtMonth + warrantyMonths;

  // set the month to bought object
  bought.setMonth(warrantyMonth);

  // result
  console.log(bought);
}

// adding event listeners on the input boxes
document.querySelector('#bought').addEventListener('change', calculateWarranty);
document.querySelector('#warranty').addEventListener('change', calculateWarranty);

<input id="bought" name="bought" class="textbox-n form-control" type="text" placeholder="Date Bought" onfocus="(this.type='date')" onblur="(this.type='text')" />

<input id="warranty" name="warranty" class="textbox-n form-control" type="number" value="1" />

您还需要在代码中添加一些错误处理。