String formatting with printf: - Revision history

Nmingott at 19:11, 5 May 2025

2025-05-05T19:11:29Z

← Older revision		Revision as of 19:11, 5 May 2025
Line 74:		Line 74:
	* Align a string the center of a fixed space. (this is not available in C but it would be nice to have)		* Align a string the center of a fixed space. (this is not available in C but it would be nice to have)

	----Dr. Nicola Mingotti last ~~updated~~ on 06-~~Sep~~-~~2021~~. Tested in ~~Cuis5.0-4834.image~~.		----Dr. Nicola Mingotti last checked on 05-May-2025. Tested in Cuis rolling release.

Nmingott: corrected bug

2025-05-05T19:10:28Z

corrected bug

← Older revision		Revision as of 19:10, 5 May 2025
Line 56:		Line 56:
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .
	PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .
	'\_0.2f' printf: {1234.567}. "=> '1_234.56' "		'_0.2f' printf: {1234.567}. "=> '1_234.56' "
	</syntaxhighlight>		</syntaxhighlight>

Nmingott: corrections and found bug

2025-05-05T18:58:16Z

corrections and found bug

← Older revision		Revision as of 18:58, 5 May 2025
Line 30:		Line 30:
	"=> 'Name Last name mail ' "		"=> 'Name Last name mail ' "

	". classic newline "		". BROKEN-at-2025-05-05 --- classic newline "
	'line1\nline2' printf: nil. "=> 'line1		'line1\nline2' printf: nil. "=> 'line1
	line2' "		line2' "
Line 42:		Line 42:

	". print a float number with default thousand separator, tested for %f and %d. "		". print a float number with default thousand separator, tested for %f and %d. "
	'%\_0.2f' printf: {1234.567}. "=> '~~1\_234~~.56' "		'%_0.2f' printf: {1234.567}. "=> '1_234.56' "

	". Change format for thousand separator and decimal separator "		". Change format for thousand separator and decimal separator "
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $, .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $, .
	'%\_0.2f' printf: {1234.567}. "=> '1,234.56' "		'%_0.2f' printf: {1234.567}. "=> '1,234.56' "

	". now let's print the number in the way it is considered 'normal' in Italy, for example "		". now let's print the number in the way it is considered 'normal' in Italy, for example "
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $. .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $. .
	PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: $, .		PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: $, .
	'%\_0.2f' printf: {1234.567}. "=> '1.234,56' "		'%_0.2f' printf: {1234.567}. "=> '1.234,56' "

	". and let's put back the default configuaration "		". and let's put back the default configuaration "
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .
	PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .
	'%\_0.2f' printf: {1234.567}. "=> '~~1\_234~~.56' "		'\_0.2f' printf: {1234.567}. "=> '1_234.56' "
	</syntaxhighlight>		</syntaxhighlight>

Nmingott: dotted list of problems

2025-05-04T22:59:56Z

dotted list of problems

← Older revision		Revision as of 22:59, 4 May 2025
Line 1:		Line 1:
			'''Problems'''.
⚫	~~'''Problem'''. How can I print out a text table? How can I format numbers with only 2 decimals?~~ How can I pad a number to fixed with putting zeros in front of it?

			* How can I print out a text table?
			* How can I format numbers with only 2 decimals?
		⚫	* How can I pad a number to fixed with putting zeros in front of it?
			* ...

	'''Solution'''. These and more little everyday problems can be solved with <code>String>>printf:</code> . See the examples below.		'''Solution'''. These and more little everyday problems can be solved with <code>String>>printf:</code> . See the examples below.

Nmingott at 22:58, 4 May 2025

2025-05-04T22:58:39Z

← Older revision		Revision as of 22:58, 4 May 2025
Line 12:		Line 12:

	". pad an integer with starting zeros to make it a deault lenght"		". pad an integer with starting zeros to make it a deault lenght"
	'padding a number: %05d' printf: 123. " 'padding a number: 00123' "		'padding a number: %05d' printf: 123. "=> 'padding a number: 00123' "

	". print a floating point with as many decimals you wish"		". print a floating point with as many decimals you wish"
	'3 decimals: %.3f' printf: 123.456789. " '3 decimals: 123.456' "		'3 decimals: %.3f' printf: 123.456789. "=> '3 decimals: 123.456' "

	". fixed length strings, good for tables "		". fixed length strings, good for tables "
	'%15s %15s %10s' printf: {'Name'. 'Last name'. 'mail'} ~~" ' Name Last name mail' "~~		'%15s %15s %10s' printf: {'Name'. 'Last name'. 'mail'}.
			"=> ' Name Last name mail' "

	". fixed length strings, align left, good for tables "		". fixed length strings, align left, good for tables "
	'%-15s %-15s %-10s' printf: {'Name'. 'Last name'. 'mail'}. ~~" 'Name Last name mail ' "~~		'%-15s %-15s %-10s' printf: {'Name'. 'Last name'. 'mail'}.
			"=> 'Name Last name mail ' "

	". classic newline "		". classic newline "
Line 31:		Line 33:

	<syntaxhighlight lang="smalltalk">		<syntaxhighlight lang="smalltalk">
	". print an integer with thousand separators "		". print an integer with thousand separators "
	'%_d' printf: {1234} "=> '1_234' "		'%_d' printf: {1234}. "=> '1_234' "

	". print a float number with default thousand separator, tested for %f and %d. "		". print a float number with default thousand separator, tested for %f and %d. "
	'%\_0.2f' printf: {1234.567} "=> '1\_234.56' "		'%\_0.2f' printf: {1234.567}. "=> '1\_234.56' "

	". Change format for thousand separator and decimal separator "		". Change format for thousand separator and decimal separator "
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $, .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $, .
	'%\_0.2f' printf: {1234.567}. "=> '1,234.56' "		'%\_0.2f' printf: {1234.567}. "=> '1,234.56' "

	". now let's print the number in the way it is considered 'normal' in Italy, for example "		". now let's print the number in the way it is considered 'normal' in Italy, for example "
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $. .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $. .
	PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: $, .		PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: $, .
	'%\_0.2f' printf: {1234.567} "=> '1.234,56' "		'%\_0.2f' printf: {1234.567}. "=> '1.234,56' "

	". and let's put back the default configuaration "		". and let's put back the default configuaration "
	PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .
	PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .
	'%\_0.2f' printf: {1234.567} "=> '1\_234.56' "		'%\_0.2f' printf: {1234.567}. "=> '1\_234.56' "
	</syntaxhighlight>		</syntaxhighlight>

Line 55:		Line 57:

	* Formatting a number in scientific notation: `%e`, `%E`, `%g`.		* Formatting a number in scientific notation: `%e`, `%E`, `%g`.
			<syntaxhighlight lang="smalltalk">

	"?scientifig notation -- broken ?"		"?scientifig notation -- broken ?"
	'scientific: %e' printf: 123345.1234. " 'scientific: 123345.1' "		'scientific: %e' printf: 123345.1234. "=> 'scientific: 123345.1' "
			</syntaxhighlight>

	* Formatting a number in scientific notation: `%e`, `%E`, `%g`.		* Formatting a number in scientific notation: `%e`, `%E`, `%g`.
			<syntaxhighlight lang="smalltalk">

	"?scientifig notation -- broken ?"		"?scientifig notation -- broken ?"
	'scientific: %e' printf: 123345.1234. " 'scientific: 123345.1' "		'scientific: %e' printf: 123345.1234. "=> 'scientific: 123345.1' "
			</syntaxhighlight>

	* Formatting a long number splitting it on thousands <code>%'</code>.		* Formatting a long number splitting it on thousands <code>%'</code>.
	* Align a string the center of a fixed space. (this is not available in C but it would be nice to have)		* Align a string the center of a fixed space. (this is not available in C but it would be nice to have)

Nmingott at 22:46, 4 May 2025

2025-05-04T22:46:29Z

← Older revision		Revision as of 22:46, 4 May 2025
Line 2:		Line 2:

	'''Solution'''. These and more little everyday problems can be solved with <code>String>>printf:</code> . See the examples below.		'''Solution'''. These and more little everyday problems can be solved with <code>String>>printf:</code> . See the examples below.
			<syntaxhighlight lang="smalltalk">
	"to use :printf you must load this package"		"to use :printf you must load this package"
	Feature require:'Printf'		Feature require:'Printf'
			</syntaxhighlight>

			<syntaxhighlight lang="smalltalk">
	". print an integer"		". print an integer"
	'a number : %d' printf: 123. " 'a number : 123' "		'a number : %d' printf: 123. " 'a number : 123' "
Line 23:		Line 26:
	'line1\nline2' printf: nil. "=> 'line1		'line1\nline2' printf: nil. "=> 'line1
	line2' "		line2' "
			</syntaxhighlight>

	* Thousand separators and locales		* Thousand separators and locales

			<syntaxhighlight lang="smalltalk">
	". print an integer with thousand separators "		". print an integer with thousand separators "
	'%_d' printf: {1234} "=> '1_234' "		'%_d' printf: {1234} "=> '1_234' "
Line 45:		Line 50:
	PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .		PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .
	'%\_0.2f' printf: {1234.567} "=> '1\_234.56' "		'%\_0.2f' printf: {1234.567} "=> '1\_234.56' "
			</syntaxhighlight>

	== Things that still do not work or are not implemented ==		== Things that still do not work or are not implemented ==

Nmingott: importe material

2025-05-03T23:38:05Z

importe material

New page

'''Problem'''. How can I print out a text table? How can I format numbers with only 2 decimals? How can I pad a number to fixed with putting zeros in front of it?

'''Solution'''. These and more little everyday problems can be solved with <code>String>>printf:</code> . See the examples below.
"to use :printf you must load this package"
Feature require:'Printf'

". print an integer"
'a number : %d' printf: 123. " 'a number : 123' "

". pad an integer with starting zeros to make it a deault lenght"
'padding a number: %05d' printf: 123. " 'padding a number: 00123' "

". print a floating point with as many decimals you wish"
'3 decimals: %.3f' printf: 123.456789. " '3 decimals: 123.456' "

". fixed length strings, good for tables "
'%15s %15s %10s' printf: {'Name'. 'Last name'. 'mail'} " ' Name Last name mail' "

". fixed length strings, align left, good for tables "
'%-15s %-15s %-10s' printf: {'Name'. 'Last name'. 'mail'}. " 'Name Last name mail ' "

". classic newline "
'line1\nline2' printf: nil. "=> 'line1
line2' "

* Thousand separators and locales

". print an integer with thousand separators "
'%_d' printf: {1234} "=> '1_234' "

". print a float number with default thousand separator, tested for %f and %d. "
'%\_0.2f' printf: {1234.567} "=> '1\_234.56' "

". Change format for thousand separator and decimal separator "
PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $, .
'%\_0.2f' printf: {1234.567}. "=> '1,234.56' "

". now let's print the number in the way it is considered 'normal' in Italy, for example "
PrintfNumberFormatDescriptor setUserThousandSeparatorTo: $. .
PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: $, .
'%\_0.2f' printf: {1234.567} "=> '1.234,56' "

". and let's put back the default configuaration "
PrintfNumberFormatDescriptor setUserThousandSeparatorTo: nil .
PrintfNumberFormatDescriptor setUserDecimalSeparatorTo: nil .
'%\_0.2f' printf: {1234.567} "=> '1\_234.56' "

== Things that still do not work or are not implemented ==

* Formatting a number in scientific notation: `%e`, `%E`, `%g`.

"?scientifig notation -- broken ?"
'scientific: %e' printf: 123345.1234. " 'scientific: 123345.1' "

* Formatting a number in scientific notation: `%e`, `%E`, `%g`.

"?scientifig notation -- broken ?"
'scientific: %e' printf: 123345.1234. " 'scientific: 123345.1' "

* Formatting a long number splitting it on thousands <code>%'</code>.
* Align a string the center of a fixed space. (this is not available in C but it would be nice to have)

----Dr. Nicola Mingotti last updated on 06-Sep-2021. Tested in Cuis5.0-4834.image.