format

Type

function

Summary

Returns a formatted string that has been transformed according to the rules of the C "printf()" function.

Syntax

format(<baseString> [, <valuesList>])

Description

Use the format function to create strings in special formats.

The format function works by taking a baseString that contains formatting incantations, transforming each member of the valuesList according to the corresponding incantation, then substituting the transformed string for the incantation in the baseString. It also transforms C escape sequences in the baseString into their single- character equivalents.

The valid incantations are as follows: String:- %[charLength]s - The corresponding value is unchanged, except that if a charLength is specified, if the string is shorter than the charLength, enough leading spaces are added to make it charLength characters long. If the length of the string is equal to or greater than the charLength, it is unchanged. For example, the incantation %3s transforms "H" to " H". Character:- %[charLength]c - The corresponding value is treated as an ASCII value and translated to the corresponding character. If a charLength is specified, one fewer leading spaces are added to make it charLength characters long. For example, the incantation %2c transforms 65 to " A" (65 is the ASCII value of the character "A").

Decimal number:

• %[charLength]d - The corresponding value is rounded to the nearest integer: if the fractional part is .5 or more, the value is rounded up, and otherwise it is rounded down. (If the value is negative, if the fractional part is .5, the value is rounded down.) If a charLength is specified, if the length of the resulting number is less than the charLength, enough leading spaces are added to make it charLength characters long. If the length of the resulting number is equal to or greater than the charLength, it is unchanged. For example, the incantation %2d transforms "2.3" to " 2".

Unsigned integer:

• %[charLength]u - Like %[charLength]d, except that if the value is negative, it is subtracted from the largest long integer allowed by the current operating system. (On most operating systems, this is 2^32, or 4,294,967,296.) Octal:- %[charLength]o - The corresponding value is assumed to be a decimal number, rounded to the nearest integer, then converted to an octal number. If a charLength is specified, if the length of the resulting number is less than the charLength, enough leading spaces are added to make it charLength characters long. If the length of the resulting number is equal to or greater than the charLength, it is unchanged. For example, the incantation %3o transforms "10.7" to " 13". Hexadecimal:- %[charLength]x - The corresponding value is assumed to be a decimal number, rounded to the nearest integer, then converted to a hexadecimal number. If a charLength is specified, if the length of the resulting number is less than the charLength, enough leading spaces are added to make it charLength characters long. If the length of the resulting number is equal to or greater than the charLength, it is unchanged. For example, the incantation %4x transforms "30.3" to " 1e".
• %[charLength]X - Like %[charLength]x, except that the hex digits A-F are given in uppercase. For example, the incantation %4x transforms "30.3" to " 1E".

Floating-point:

• %[charLength].[precision]f - The corresponding value is a real number. If a precision is specified, if the number of digits after the decimal point is greater than the precision, the number is rounded to the specified number of digits after the decimal point. If the number of digits is less than the precision, enough trailing zeroes are added to make precision digits. If no precision is specified, the number is formatted to six decimal places. If a charLength is specified, if the total length of the resulting number is less than the charLength, enough leading spaces are added to make it charLength characters long; if the length of the resulting number is equal to or greater than the charLength, it is unchanged.
• %[charLength. precision]g - Like %[charLength].[precision]f, except that trailing zeroes are not added if the number of digits is less than the precision.

Scientific notation:

• %[charLength].[precision]e - The corresponding value is a real number. First the number is transformed to scientific notation: expressed as a number between 1 and 10 (or -10 and 1), multiplied by the appropropriate power of 10. If a precision is specified, if the number of digits after the decimal point is greater than the precision, the number is rounded to the specified number of digits after the decimal point. If the number of digits is less than the precision, enough trailing zeroes are added to make precision digits. If no precision is specified, the number is given to six digits after the decimal point. If a charLength is specified, if the total length of the resulting number is less than the charLength, enough leading spaces are added to make it charLength characters long; if the length of the resulting number is equal to or greater than the charLength, it is unchanged. For example, the incantation %3.2e transforms "232.4" to "2. 32e+02".
• %[charLength.precision]E - Like %[charLength. precision]e, except that the "E" separating the number from the power of ten is uppercase. For example, the incantation %3.2e transforms "232.4" to "2.32E+02".

If a zero is included immediately before the charLength parameter in any formatting incantation that allows padding, the resulting value is padded (if necessary) with zeroes instead of spaces. For example, the incantation %03s transforms H to 00H.

If any of the following C escape sequences are present in the baseString, the format function transforms them to the equivalent character:

• \a Control-G (bell)
• \b Control-H (backspace)
• \f Control-L (formfeed)
• \n Control-J (linefeed)
• \r Control-M (return)
• \t Control-I (tab)
• \v Control-K (vertical tab)
• \\ \
• ?? ?
• \' '
• \" " (enclose a quote within a string)
• \nnn character whose ASCII value is the octal number represented by nnn
• \xnn character whose ASCII value is the hex number represented by nn

note

Transformation of values in valuesList uses the standard LiveCode conversion rules. For example, if empty is passed for a numeric incantation it will be taken as the value 0.

Parameters

Name	Type	Description
baseString	string	A string that can include one or more special formatting incantations.
valuesList		A list of strings (or expressions that evaluate to strings), separated by commas. The valuesList contains as many values as there are incantations in the baseString.

Examples

format("Hello world")

format("Hello\nworld")

format("%1.3e",865.3)

format("%45d",5)

Related

control structure: function

function: binaryEncode, charToNum, baseConvert, numToChar

glossary: format, string, decimal point

keyword: string, character, characters

property: HTMLText, numberFormat

Compatibility and Support

Introduced

LiveCode 1.0

OS

mac

windows

linux

ios

android

Platforms

desktop

server

mobile