AbdulBazith's avatar

calculation problem in javascript, showing NaN error

Guys iam working with a project Inventory control.

i have a purchase order form.

in that form i have array of textboxes in row format.

so if admin needs he can add new rows.

this is my blade file

 <td>
        <input type="text" class="rate_per_kg" name="total_qty[]"  />
    </td>

  <td>
        <input type="text" class="rate_per_kg" name="rate_per_kg[]"  />
    </td>

 <td>
        <input type="text" class="discount_amount" name="discount_amount[]"  />
    </td>

<td>
        <input type="text" class="total_amount" name="total_amount[]"  />
    </td>



<td>
        <input type="text" class="grand_total" name="grand_total"  />
    </td>

i tried validation for this that worked fine for me.

this is the validation for total_rate[]

var total_rate = document.getElementsByName('total_rate[]');

for (var i = 0; i < total_rate.length; i++) {
    if (total_rate[i].value == "") {
        alert("Fill the Total Rate");
        total_rate[i].focus();
        return false;
    }
}

this works fine. if admin leaves the total_rate[] empty then alert is displayed and focused.

Now my question is i need to perform calculation also.

so i followed the same technique

whats my calculation is. the total_qty[] column will be filled automatcaiily when page refreshed.

so when admin enters the total_rate[]. so total_qty/total_rate the total_rate divided by total_qty must be done and the result must be displayed in the third column rate_per_kg[]

so for this i followed.

for (var i = 0; i < total_rate.length; i++) {
  var total_rate= total_rate[i].value;
   var total_qty = total_qty [i].value;
 var rate_per_kg=total_rate/total_qty ;
 rate_per_kg[i].value = rate_per_kg;
}

this works for me for the first row only. but in the second row rate_per_kg NaN is displayed.

and also there is a error in the console

1:472 Uncaught TypeError: Cannot read property 'length' of undefined

why?

that calculation must be done for the first row only. how this is possible??

this is the screen shot of that

Refer: https://imgur.com/DQOLsv7

actually i asked the question more that 3 times in the forum. but i cant get it.

now i have the loop and also the calculation.

i think there is a small error.

ithink the for loop is running for all the rows.

Kindly some one help please.

0 likes
6 replies
diegoaurino's avatar

Have you tried to use "Number()" in your values before the calculation? I believe it can be a typecasting problem.

ProHomeworkHelp's avatar

The subtotal seems to have been accurately calculated, but there was an unexpected result in adding the tax. Can you spot the trend in the operations above which allowed for safe calculations, and how that broke down. XYZ Homework

AbdulBazith's avatar
AbdulBazith
OP
7 years ago
Best Answer
Level 5

@diegoaurino thank you for you response.

what i did is

I tried some like this and it worked...


//in my <td>


onkeyup="calculation()"   // for all the textbox i given this onkeyup() event


// in my blade file js


 var total_rate = document.getElementsByName('total_rate[]');

        var pqty = document.getElementsByName('p_qty[]');

        var rate_per_kg = document.getElementsByName('rate_per_kg[]');

        var gst_percent = document.getElementsByName('gst_percent[]');

        var gst_amt = document.getElementsByName('gst_amt[]');

        var disc_percent = document.getElementsByName('disc_percent[]');

        var disc_amt = document.getElementsByName('disc_amt[]');

        var added_amount = document.getElementsByName('added_amount[]');

        var total_amount = document.getElementById('total_amount');

        total_amount.value = 0;

        for (var i = 0; i < rate_per_kg.length; i++) {

            rate_per_kg[i].value = parseInt(total_rate[i].value) / parseInt(pqty[i].value);
            gst_amt[i].value = parseInt(total_rate[i].value) * (gst_percent[i].value / 100);
            disc_amt[i].value = parseInt(total_rate[i].value) * (disc_percent[i].value / 100);

            added_amount[i].value = (parseInt(total_rate[i].value) + parseInt(gst_amt[i].value)) - parseInt(disc_amt[i].value) ;

            total_amount.value = parseInt(total_amount.value) + parseInt(added_amount[i].value);

        }

this gave the output... calculated the values and also total the final value..

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