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

Number Calculation

 


<html>
<head>
<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 += "$";

}

</script>


</head>
<body>

<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>
</select>

<br>


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

</form>
</body>
</html>

Related examples in the same category

1.	Define variables, assign values and output
2.	Dividing by Zero
3.	Add Four Numbers from an HTML Form (and Display the Results)
4.	Add characters
5.	Complex class to represent complex numbers
6.	A Function That Returns the Sum of Three Numbers (Stripped-Down Version)
7.	Concatenating Variables and Displaying the Value Contained
8.	JavaScript Loan Calculator
9.	Factorials
10.	Converting a Number to a String
11.	Creating Number Objects Rather than Performing String-to-Number Conversions
12.	Using toString() with Radix Values
13.	Using JavaScript Integers
14.	Conversion of Logical Values to Numeric Values
15.	Using Floating-Point Numbers
16.	Automatic Conversion between Types
17.	Explicit Conversion Functions
18.	Date Object Calculations
19.	Operator Precedence and Different Data Types
20.	Converting Base 10 to Base 16 Using Bitwise Operators
21.	Format a number
22.	Format a number 2
23.	Decimal to 2 Hex
24.	Concatenate integer variable to a string variable