How to calculate currency by appearing decimal places in JS?

Question

I have a dynamic calculation to do, without having to click buttons. I did, but the part I don’t know how to make it appear like decimal places, since we’re talking about currency.

function multiplica()
{
numer1 = parseInt(document.frmitementrada.quantidade.value);
numer2 = parseInt(document.frmitementrada.preuni.value);

soma = numer1 + numer2;

document.frmitementrada.total.value = soma;
}

<form name="frmitementrada" id="frmitementrada">
<td width="20%">

<INPUT TYPE="text" SIZE="3" NAME="quantidade" value="0">
<INPUT TYPE="text" onkeyup="multiplica()" SIZE="3" NAME="preuni"  value="0" >

<INPUT TYPE="text" SIZE="3" NAME="total">
</td>
</form>

Answer 1

Instead of parseInt(), use parseFloat().

The parseInt transforms into whole numbers, that is, without decimals. Already the parseFloat transforms into any operable number.

function multiplica()
{
numer1 = parseFloat(document.frmitementrada.quantidade.value);
numer2 = parseFloat(document.frmitementrada.preuni.value);

soma = numer1 + numer2;

document.frmitementrada.total.value = soma;
}

<form name="frmitementrada" id="frmitementrada">
<td width="20%">

<INPUT TYPE="text" SIZE="3" NAME="quantidade" value="0" />
<INPUT TYPE="text" onkeyup="multiplica()" SIZE="3" NAME="preuni"  value="0" />

<INPUT TYPE="text" SIZE="3" NAME="total" />
</td>
</form>

But remember that you have to use stitch ., instead of a comma ,, to the decimal places.

If you want to limit the decimals, you can use the .toFixed(), or the .toPrecision().

The toFixed, limits the number of boxes after the comma, already the toPrecision limits the house number altogether. In your case, using the toFixed:

function multiplica()
{
numer1 = parseFloat(document.frmitementrada.quantidade.value);
numer2 = parseFloat(document.frmitementrada.preuni.value);

soma = numer1 + numer2;

document.frmitementrada.total.value = (soma.toFixed(2));
}

<form name="frmitementrada" id="frmitementrada">
<td width="20%">

<INPUT TYPE="text" SIZE="3" NAME="quantidade" value="0" />
<INPUT TYPE="text" onkeyup="multiplica()" SIZE="3" NAME="preuni"  value="0" />

<INPUT TYPE="text" SIZE="3" NAME="total" />
</td>
</form>