Actionscript Cookbook

5.5. Formatting Numbers for Display

Problem

You want to format a number with a custom decimal delimiter, thousands delimiters, and/or leading spaces.

Solution

Create a custom Math.formatNumber( ) method.

Discussion

ActionScript does not include a built-in way to format numbers as strings, so you need to create a custom method to handle this for you. Furthermore, the delimiter used to indicate decimals and thousands varies by country. For example, the number represented as 1,234.56 in the United States is written as 1.234,56 in many countries. Using some basic string, array, and mathematical methods, we can create a custom method to format numbers with a configurable decimal delimiter (i.e., 123.4 or 123,4), configurable thousands delimiters (i.e., 1,234 or 1.234), and optional leading spaces (to align values when using a monospace font).

Our custom Math.formatNumber( ) method accepts four parameters:

num

The number you want to format

thousandsDelim

The value to use for delimiting the thousands, millions, billions, etc. places

decimalDelim

The value to use for delimiting the decimal places

spaceFill

Specifies the number of total spaces the formatted string should occupy (optional)

Here is our method definition, which can be added to Math.as for easy inclusion in your projects:

Math.numberFormat = function (num, thousandsDelim, decimalDelim, spaceFill) { // Default to a comma for thousands and a period for decimals. if (thousandsDelim == undefined) {thousandsDelim = ",";} if (decimalDelim ...