Article Categories
- All Categories
-
Data Structure
-
Networking
-
RDBMS
-
Operating System
-
Java
-
MS Excel
-
iOS
-
HTML
-
CSS
-
Android
-
Python
-
C Programming
-
C++
-
C#
-
MongoDB
-
MySQL
-
Javascript
-
PHP
-
Economics & Finance
How to format a rounded number to N decimals using JavaScript?
Use the toFixed() method to format a rounded number to N decimals. The toFixed() method formats a number with a specific number of digits to the right of the decimal point and returns a string representation.
Syntax
number.toFixed(digits)
Parameters
digits (optional): An integer specifying the number of digits after the decimal point. Must be in the range 0-100. Default is 0.
Return Value
Returns a string representation of the number with the specified number of decimal places.
Example
Here's how to format numbers to different decimal places:
<html>
<head>
<title>JavaScript toFixed() Method</title>
</head>
<body>
<script>
var num = 15;
document.write("num.toFixed() is : " + num.toFixed());
document.write("<br />");
document.write("num.toFixed(2) is : " + num.toFixed(2));
document.write("<br />");
document.write("num.toFixed(1) is : " + num.toFixed(1));
document.write("<br />");
// Example with decimal number
var decimal = 3.14159;
document.write("decimal.toFixed(2) is : " + decimal.toFixed(2));
document.write("<br />");
document.write("decimal.toFixed(4) is : " + decimal.toFixed(4));
</script>
</body>
</html>
Output
num.toFixed() is : 15 num.toFixed(2) is : 15.00 num.toFixed(1) is : 15.0 decimal.toFixed(2) is : 3.14 decimal.toFixed(4) is : 3.1416
Rounding Behavior
The toFixed() method rounds the number when necessary:
<html>
<body>
<script>
var price = 19.456;
document.write("Original: " + price);
document.write("<br />");
document.write("Rounded to 2 decimals: " + price.toFixed(2));
document.write("<br />");
document.write("Rounded to 1 decimal: " + price.toFixed(1));
document.write("<br />");
document.write("Rounded to 0 decimals: " + price.toFixed(0));
</script>
</body>
</html>
Output
Original: 19.456 Rounded to 2 decimals: 19.46 Rounded to 1 decimal: 19.5 Rounded to 0 decimals: 19
Key Points
-
toFixed()returns a string, not a number - If no parameter is provided, it defaults to 0 decimal places
- The method performs rounding when necessary
- Trailing zeros are added to reach the specified decimal places
Conclusion
The toFixed() method is the standard way to format numbers to a specific number of decimal places in JavaScript. It handles rounding automatically and always returns a string representation with the exact number of decimals specified.
513 Views
