**Operator Type:**

**Operator Scope of Action:**

**Operator Purpose:**

**Operator First Added:**

**Operator Altered:**

Function [other Function type actions]

Item [operators of similar scope]

Formatting [other Formatting operators]

5.8.0

5.10.3

**Number.format(decimalsN[,widthN])**

Returns **Number** as a string, formatted to **decimalsN** decimal places.

If **widthN** is supplied, Number returned additionally left padded with spaces so that **widthN** equals the sum of: [padding spaces]+[minus sign]+integer number(s)+decimal point+[decimal numbers]. Note that with **widthN**, decimal character is *not* counted as part of the number. The presence of a minus sign is

For example, if $MyNum is 3.1415927, then

`$MyNum.format(2`

) is 3.14

`$MyNum.format(0)`

is 3

`$MyNum.format(2,7)`

is " 3.14" (3 left padding spaces + 1 integer number + decimal point + 3 decimal numbers = 7)

But if $MyNum is negative, e.g. -3.1415927, then

`$MyNum.format(2,7)`

is " -3.14" (2 left padding spaces + minus sign + 1 integer number + decimal point + 3 decimal numbers = 7)

Literal numbers, e.g. 3.1415927, can also be worked with:

`5.1415927.format(2)`

is 5.14

The above works but the following syntax may seem less ambiguous by using parentheses to delimit the literal number:

`(5.1415927).format(2)`

is 5.14

`(5.1415927).format(1,5)`

is ' 5.1' (two left padding spaces + 1 integer number + decimal point + 1 decimal number = 5)

If a group of numbers are being formatted so as to vertically decimal-point align as a column figures, e.g. financial data, it is necessary to know the widthN of 'longest' number to be used, remembering that a negative number adds one to its width count; 45 is width 2, -45 is width 3. In the example below the longest (**widthN**) number in a set of currency figures has been worked out stored in a user Number attribute $MaxNumLen. Being currency, 2 decimal places will be enforced, and each number can be evaluated by a common formatting:

`[the number].format(2,$MaxLenNum)`

If the widthN for a set of numbers can't easily be assessed, an alternate option is simply to use a number known to be bigger than all likely width valid. Thus *every* number, including the longest gets left-padded - but all end up correctly aligned. In the latter example if all numbers are always likely to be less than 20, then $MaxLenNum could be set to 20, or simply used directly:

`[the number].format(2,$MaxLenNum)`

There is no easy way in v5 to sort a list of numbers on size (i.e. their **widthN**), other than by looping the list via List.each() transforming each to a string (using zero decimal places!), saving the String.size of each of these as a number in a new list, then List.nsort() and take the last item, .at(-1). As .nsort() sorts on ascending numerical order, the latter will be the size of the longest string (including negative numbers) in the original list. Assuming $MySizeList has all the size strings:

` $MaxLenNum = ($MySizeList.nsort).at(-1)`

Why leave out decimal places when coercing the numbers to strings? 1234.56 is a bigger number than 12.34567, but the latter is the bigger size. However, 1234 is both a bagger and 'wider' than 12.

As can be seen, just setting a large arbitrary **widthN** might save a lot of messing about!

**Number.format("formatString")**

New to v5.10.3, an alternate usage is to supply a quoted **formatString**. Currently only one such string is supported: "L". This will return a string of the number formatted with (OS) locale-dependent group & decimal delimiters. For example, for the US locale these are a comma and a period; in other locales they may vary.

This function supplements the existing format() and Number.precision() functions.