Question

所以我有两个输入文本字段和两个选项选择字段，货币兑换计算器。第一个输入字段和两个选择选项的值用于计算最终值。

我想要实现的是用户输入左输入 - 例如“20a” - 修剪“a”或任何其他字符串并继续计算值。

提前非常感谢。这是我的代码：

function calculusSmaller(cur1, cur2) {
    calculatedCurrency.value = parseFloat(currVal * (cur1 / cur2)).toFixed(2);
}

function calculusBiger(cur1,cur2) {
    calculatedCurrency.value = parseFloat(currVal * (cur1 * cur2)).toFixed(2);
}

//adjusting values if empty or NaN

if (!isNaN(placeholderCurrency.value)) {
    placeholderCurrency.parentNode.removeAttribute('data-error');
}else {
    //HERE is the code needed, trimming the String.
    placeholderCurrency.parentNode.setAttribute('data-error', 'Please enter a number');
    mainCurrency();
} 

if (placeholderCurrency.value == "") {
    resetValues();
}

function mainCurrency(var1, var2) {
    var1 = firstValue;
    var2  = secondValue;
    switch(var1 + "|" + var2) {
        case "usd|rsd":
            calculusBiger(usd,rsd);
        break;
        case "eur|rsd":
            calculusBiger(eur,rsd);
        break;
        case "rsd|usd":
            calculusSmaller(rsd,usd);
        break;
        case "rsd|eur":
                calculusSmaller(rsd,eur);
        break;
        case "eur|usd":
            calculusSmaller(eur,usd);
        break;
        case "usd|eur":
            calculusSmaller(usd,eur);
        break;
        default:
            resetValues();
    }

    console.log('test');
}      

mainCurrency();

这是HTML：

<select name="selectedCurrency">
    <option class="" data="0"  value="rsd">Rsd</option>
    <option class="" data = "2" value="eur" selected="selected" >Eur</option>
    <option class="" data = "1" value="usd" >Usd</option>
</select>
<input value="1" type="text"  name="placeholder-currency">

<select name="currentCurrency">
    <option class="" data="0" selected="selected" value="rsd">Rsd</option>
    <option class="" data="2" value="eur">Eur</option>
    <option class="" data="1" value="usd">Usd</option>
</select>
<input type="text" value="1" name="calculated-currency">

Answer 1

这是一个使用onkeypress的例子。

＆＃13;

<html>

<head>
  <link rel="stylesheet" href="style.css">
  <script src="script.js"></script>
</head>

<body>
  <select name="selectedCurrency">
    <option class="" data="0" value="rsd">Rsd</option>
    <option class="" data="2" value="eur" selected="selected">Eur</option>
    <option class="" data="1" value="usd">Usd</option>
  </select>
  <input value="1" type="text" name="placeholder-currency" onkeypress="return isNumber(event)">

  <select name="currentCurrency">
    <option class="" data="0" selected="selected" value="rsd">Rsd</option>
    <option class="" data="2" value="eur">Eur</option>
    <option class="" data="1" value="usd">Usd</option>
  </select>
  <input type="text" value="1" name="calculated-currency" onkeypress="return isNumber(event)">
  <script>
    function calculusSmaller(cur1, cur2) {
      calculatedCurrency.value = parseFloat(currVal * (cur1 / cur2)).toFixed(2);
    }

    function calculusBiger(cur1, cur2) {
      calculatedCurrency.value = parseFloat(currVal * (cur1 * cur2)).toFixed(2);
    }

    //adjusting values if empty or NaN

    if (!isNaN(placeholderCurrency.value)) {
      placeholderCurrency.parentNode.removeAttribute('data-error');
    } else {
      //HERE is the code needed, trimming the String.
      placeholderCurrency.parentNode.setAttribute('data-error', 'Please enter a number');
      mainCurrency();
    }

    if (placeholderCurrency.value == "") {
      resetValues();
    }

    function mainCurrency(var1, var2) {
      var1 = firstValue;
      var2 = secondValue;
      switch (var1 + "|" + var2) {
        case "usd|rsd":
          calculusBiger(usd, rsd);
          break;
        case "eur|rsd":
          calculusBiger(eur, rsd);
          break;
        case "rsd|usd":
          calculusSmaller(rsd, usd);
          break;
        case "rsd|eur":
          calculusSmaller(rsd, eur);
          break;
        case "eur|usd":
          calculusSmaller(eur, usd);
          break;
        case "usd|eur":
          calculusSmaller(usd, eur);
          break;
        default:
          resetValues();
      }

      console.log('test');
    }

    function isNumber(event) {
      event = (event) ? event : window.event;
      var charCode = (event.which) ? event.which : event.keyCode;
      if (charCode > 31 && (charCode < 48 || charCode > 57) && charCode !== 46) return false;
      return true;
    }

    mainCurrency();
  </script>
</body>

</html>

＆＃13;

输入文本的修剪值为NaN，以便进一步计算。只有JS

1 个答案: