Number Calculation : Number Data Type « Language Basics « JavaScript DHTML

Number Calculation


<title>Prices Demo</title>

<script language="javascript">

function calculation() {
  var number= document.prices.quantity.value;
  total = "" + Math.round((number*12.95)*100)/100;

  if (total.indexOf(".") == -1) 
    total += ".00"; 
  else if (total.indexOf(".") == total.length-2) 
    total += "0"; 

  document.prices.subtotal.value = total += "$";




<form name="prices">

<select name="quantity" onClick="calculation()">
  <option value="0">0</option>

  <option value="1">1</option>
  <option value="2">2</option>
  <option value="3">3</option>
  <option value="4">4</option>
  <option value="5">5</option>
  <option value="6">6</option>

  <option value="7">7</option>
  <option value="8">8</option>
  <option value="9">9</option>
  <option value="10">10</option>


<input type="text" name="subtotal" value="0.00$">



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