JavaScript 小费计算器

Question

我对 Javascript 很陌生，这是我的问题我似乎无法正确理解最后两个框，并对我困惑的编码感到抱歉，因为我说过我对此还很陌生。

function FigureIt() {
  DinCost = document.tip.dinCost.value;
  Tip15 = (DinCost * .15)
  Tip25 = (DinCost * .25)
  Din15 = (DinCost * .15) + (DinCost)
  Din25 = (DinCost * .25) + (DinCost)

  document.tip.tip15.value = Tip15;
  document.tip.tip25.value = Tip25;
  document.tip.dinner15.value = Din15;
  document.tip.dinner25.value = Din25;
}

<form name="tip">
  How much did you pay for dinner? &nbsp; $<input type="text" name="dinCost" id="dinCost"> <br>
  <input type="button" value="Calculate Tips" onclick="FigureIt()"> <br> <br> Amount of 15% tip: &nbsp; $<input type="text" name="tip15" id="tip15"> <br> Amount of 25% tip: &nbsp; $<input type="text" name="tip25" id="tip25"> <br> <br> Cost of dinner +
  15% tip: &nbsp; <input type="text" name="dinner15" id="dinner15"><br> Cost of dinner + 25% tip: &nbsp; <input type="text" name="dinner25" id="dinner25"> <br>
  <input type="reset" value="Erase">
</form>

Answer 1

将您输入的晚餐费用转换为数字:

DinCost = Number(document.tip.dinCost.value);