Name: format

Type: function

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

Summary: Returns a <format|formatted> <string> that has been transformed according to the rules of the C "printf()" <function>.

Introduced: 1.0

OS: mac,windows,linux,ios,android

Platforms: desktop,server,web,mobile

Example:
format("Hello world")

Example:
format("Hello\nworld")

Example:
format("%1.3e",865.3)

Example:
format("Hello world")

Example:
format("%45d",5)

Parameters:
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>.

The result: 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".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". 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".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. 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".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</code.

Returns: The <format> function returns a <string>.

Description:
Use the <format> <function> to create <string(glossary)|strings> in special <format|formats>. 

The <format> <function> works by taking a <baseString> that contains <format|formatting> incantations, transforming each member of the <valuesList> according to the corresponding incantation, then substituting the transformed <string(keyword)> 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(keyword)> is shorter than the charLength, enough leading spaces are added to make it charLength <characters> long. If the length of the <string(keyword)> 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

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

Hexadecimal:
%[charLength]x

%[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

%[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

%[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 any of the following C escape sequences are present in the <baseString>, the <format> function transforms them to the equivalent character: 
 
\aControl-G (bell) 
\bControl-H (backspace) 
\fControl-L (formfeed) 
\nControl-J (linefeed) 
\rControl-M (return) 
\tControl-I (tab) 
\vControl-K (vertical tab) 
\\\ 
\?? 
\'' 
\(enclose a quote within a <string(keyword)>) 
\nnncharacter whose ASCII value is the octal number represented bynnn 
\xnncharacter whose ASCII value is the hex number represented by*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.

References: HTMLText (property), numberFormat (property), string (keyword), character (keyword), characters (keyword), binaryEncode (function), charToNum (function), baseConvert (function), numToChar (function), format (glossary), string (glossary), decimal point (glossary), function (control_st)

Tags: text processing
