How can JavaScript automatically calculate the sum of various numbers entered into multiple input fields?

Question

How can JavaScript automatically calculate the sum of various numbers entered into multiple input fields?

I would like to automatically add different numbers entered in multiple input fields using JavaScript.

Is there a way to calculate the sum of numbers entered in various input fields using JavaScript?

"The input field consists of n numbers..." and I am utilizing the clone function for these input fields.

https://i.sstatic.net/2XRrg.png

I am only concerned with numerical values in the input fields, not text fields. You can refer to a similar model here. Please note that the names and IDs here are different from the example provided.

Can anyone guide me on how to achieve this? Your help is greatly appreciated.

javascript

Answer 1

Answer №1

You can implement an onchange event on all input fields that need to be summed up

<input class="sum" onchange="add()" />

This script will calculate the sum and display it in the total input field:

function add(){
 total = 0;
 sum = document.getElementsByClassName("sum");
 for(a = 0; a < sum.length; a++)
   {
     console.log(sum[a].value);
     total += parseInt(sum[a].value || 0);
  }
  document.getElementById("total").value = total;
}

Demo:

function add(){
 total = 0;
 sum = document.getElementsByClassName("sum");
 for(a = 0; a < sum.length; a++)
   {
     console.log(sum[a].value);
     total += parseInt(sum[a].value || 0);
  }
  document.getElementById("total").value = total;
}

One   <input class="sum" onchange="add()" /><br/>
Two  <input class="sum" onchange="add()" /><br/>
Three <input class="sum" onchange="add()" /><br/>
Four  <input class="sum" onchange="add()" /><br/>
Total   <input id="total"  /><br/>

Answer 2

You can implement an onchange event on all input fields that need to be summed up

<input class="sum" onchange="add()" />

This script will calculate the sum and display it in the total input field:

function add(){
 total = 0;
 sum = document.getElementsByClassName("sum");
 for(a = 0; a < sum.length; a++)
   {
     console.log(sum[a].value);
     total += parseInt(sum[a].value || 0);
  }
  document.getElementById("total").value = total;
}

Demo:

function add(){
 total = 0;
 sum = document.getElementsByClassName("sum");
 for(a = 0; a < sum.length; a++)
   {
     console.log(sum[a].value);
     total += parseInt(sum[a].value || 0);
  }
  document.getElementById("total").value = total;
}

One   <input class="sum" onchange="add()" /><br/>
Two  <input class="sum" onchange="add()" /><br/>
Three <input class="sum" onchange="add()" /><br/>
Four  <input class="sum" onchange="add()" /><br/>
Total   <input id="total"  /><br/>

How can JavaScript automatically calculate the sum of various numbers entered into multiple input fields?

Answer №1

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