Question

＆＃13;

function multiplyBy()
{
        num1 = document.getElementById("firstNumber").value;
        num2 = document.getElementById("secondNumber").value;
       num3= document.getElementById("result").value = num1 * num2;
       document.getElementById("total").value = +num3 ;
}

＆＃13;

1st Number : <input type="text" id="firstNumber" value="" /><br>
2nd Number: <input type="text" id="secondNumber" value="" onchange="multiplyBy()" /><br>
<p>The Result is : <br>
<input type="text" name="result" id = "result" value=""/>
</p>
<p>Total :<br>
<input type="text" name="total" id="total" value=""/>
</p>

＆＃13;

function multiplyBy()
{
        num1 = document.getElementById("firstNumber").value;
        num2 = document.getElementById("secondNumber").value;
       num3= document.getElementById("result").value = num1 * num2;
}

＆＃13;

1st Number : <input type="text" id="firstNumber" value="" /><br>
2nd Number: <input type="text" id="secondNumber" value="" 
onchange="multiplyBy()" /><br>
<p>The Result is : <br>
<input type="text" name="result" id = "result" value=""/>
</p>

＆＃13;

我在这里乘以两个数字。如何在另一个文本框中添加这些相乘的数字。假设2＆amp; 5乘以4＆amp; 6乘以如何添加这些数字。

Answer 1

如果要计算文本框输入的更改，则需要添加事件处理程序，如下所示。

＆＃13;

function multiplyBy()
{
     var result = document.getElementById("result");
      var  num1 = document.getElementById("firstNumber").value;
       var num2 = document.getElementById("secondNumber").value;
     
     var num3= parseFloat(num1) * parseFloat(num2);// to convert entered values to float and || 0 to  use 0 if no value is there
       
       if(!isNaN(num3)){
          document.getElementById("resultPrev").value =   document.getElementById("result").value;
           document.getElementById("resultCurrent").value =   num3;
             result.value =  parseFloat(result.value || 0) + num3;
       }
        
       
}


document.getElementById("firstNumber").addEventListener("change",multiplyBy);


document.getElementById("secondNumber").addEventListener("change",multiplyBy);

＆＃13;

1st Number : <input type="text" id="firstNumber" value="" /><br>
2nd Number: <input type="text" id="secondNumber" /><br>
<p>The Previous Result is : <br>
<input type="text" name="resultPrev" id = "resultPrev" value="0"/>
</p>
<p>The Current Result is : <br>
<input type="text" name="resultCurrent" id = "resultCurrent" value=""/>
</p>
<p>The Final Result is : <br>
<input type="text" name="result" id = "result" value=""/>
</p>

＆＃13;

考虑处理非数字值。

Answer 2

试试这个。您需要使用parseFloat解析输入值。这会将字符串转换为数字。将现有结果值添加到新计算值中。 |0用于输入0的错误值

已更新

添加了prev，present和total结果框

使用新结果附加每个附加输入。

＆＃13;

var last=0;
function multiplyBy() {
  var num1 = document.getElementById("firstNumber");
  var num2 = document.getElementById("secondNumber");
  var prev = document.getElementById("prev");
  var present = document.getElementById("present");
  var total = document.getElementById("result");
  prev.value=last;
  present.value=(parseFloat(num1.value) * parseFloat(num2.value))
  last = last+(parseFloat(num1.value) * parseFloat(num2.value))
  total.value=last;
  num1.value = ""; 
  num2.value = "";

  }

＆＃13;

1st Number : <input type="text" id="firstNumber" value="" /><br> 2nd Number: <input type="text" id="secondNumber" value="" onchange="multiplyBy()" /><br>
<p >
Prev result:<br>
<input type="text" name="result"  id="prev" ><br>
Present:<br>
<input type="text" name="result"  id="present" ><br>
The total Result is : <br>
<input type="text" name="result"  id="result"><br>
</p>

＆＃13;

Answer 3

我已将multiplyBy（）添加到两个输入字段，并将类型更改为数字以限制用户仅输入数字。

请查看下面的代码段。

＆＃13;

document.getElementById("firstNumber").addEventListener("change",multiplyBy);
document.getElementById("secondNumber").addEventListener("change",multiplyBy);

function multiplyBy()
    {
    actualResult = document.getElementById("actualResult").value ? document.getElementById("actualResult").value : 0; // Return zero if there is no value in actualResult input field
            num1 = document.getElementById("firstNumber").value;
            num2 = document.getElementById("secondNumber").value;       
           num3= document.getElementById("result").value = num1 * num2;
 document.getElementById("actualResult").value = Number(actualResult) + num3;  
    }

＆＃13;

 1st Number : <input type="number" id="firstNumber" value=""/><br>
    2nd Number: <input type="number" id="secondNumber" value=""/><br>
    <p>The Current Result is : <br>
    <input type="number" name="result" id = "result" value=""/>
 </p>
   <p>Previous Result + Current Result : <br> 
    <input type="number" name="actualResult" id = "actualResult" value=""/>
    </p>

＆＃13;

Answer 4

您只需要获取文本框的值并使用结果

添加它

function multiplyBy()
{       var sum = 0;
        var num=0; 
        num1 = document.getElementById("firstNumber").value;
        num2 = document.getElementById("secondNumber").value;
        num =parseInt(num1 * num2);
        num3=parseInt(document.getElementById("result").value);
        document.getElementById("result").value=(num + num3);

}
</script>
1st Number : <input type="text" id="firstNumber" value="" /><br>
2nd Number: <input type="text" id="secondNumber" value="" 
onchange="multiplyBy()" /><br>
<p>The Result is : <br>
<input type="text" name="result" id = "result" value="0"/>
</p>

使用javascript添加相乘的数字

4 个答案: