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Function [other Function type actions]

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Formatting [other Formatting operators]

Baseline

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

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 allowed for.

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

For example, if $MyNumber is 3.1415927, then

`$MyString = $MyNumber.format(2);`

is "3.14"

`$MyString = $MyNumber.format(0);`

is "3"

`$MyString = $MyNumber.format(2,7);`

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

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

`$MyString = $MyNumber.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:

`$MyString = 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:

`$MyString = (5.1415927).format(2);`

is "5.14"

`$MyString = (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 cannot 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 $MaxLenNumber could be set to 20, or simply used directly:

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

There is no easy way 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:

`$MaxLenNumber = ($MySizeList.nsort).at(-);`

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 bigger and 'wider' than 12.

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

If the optional **padStr** is given, this specifies the character used for padding. The default is a space:

`$MyString = 7.format(0,3);`

gives " 7"

`$MyString = 7.format(0,3,"0");`

gives "007"

`$MyString = 7.format(0,3,"#");`

gives "##7"

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

An alternate usage is to supply a quoted **formatString**. Currently only one such string is supported: "l" (lowercase letter '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. For example, if $MyNumber is 4562781.4, and it is desired to display it as a string with thousands delimited:

`$MyString = $MyNumber.format("l");`

gives "4,562,781.4"

Of course, depending on the users local, the delimiter may be something else. For instance in a German locale setting, it would be "4.562.781,4". For more on such difference see Wikipedia's article on 'Decimal Separators'.

**Currency formatting**

Building on the above there are two format strings that can be used, again locale-based, to turn a Number into number string with a currency symbol prefix. Format string `"$"`

formats the number to the local currency to two decimal points. Thus if $MyNumber is `1246.878`

:

`$MyString=$MyNumber.format("$");`

sets $MyString to "$1,246.88" isn the US, "£1,246.88" in UK, "€1,246.88" in France, etc. Note how the format also respects the local thousands separate, adding a comma after the initial digit.

If such a currency string is needed rounded to the neared whole major unit, e.g. dollars and not cents, use format string `"$0"`

:

`$MyString=$MyNumber.format("$0");`

which sets $MyString to "$1,247" isn the US, "£1,247" in UK, "€1,247" in France, etc.