StringFormat() to return Decimal Only

[zeenmakr]

Couldn't work out how to return 1415 from 3.1415 with StringFormat() trying to avoid StringRegExpReplace() or StringInStr(). Thought'd be as simple as "%d" flag for decimal but not it. 

https://www.autoitscript.com/autoit3/docs/functions/StringFormat.htm

[Melba23]

zeenmakr,

Try StringSplit on the decimal point.

M23

[zeenmakr]

  On 5/31/2020 at 5:27 PM, Melba23 said:

zeenmakr,

Try StringSplit on the decimal point.

M23

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yea forgot to mention, is possible with StringFormat(). Trying to avoid all other alternatives

[Melba23]

zeenmakr,

  Quote

Trying to avoid all other alternatives

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Why? If something works why refuse to use it?

M23

[zeenmakr]

  On 5/31/2020 at 5:35 PM, Melba23 said:

Why? If something works why refuse to use it?

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it's not that, want to gain new method. after all it is StringFormat, with "%01i" flag for interger and "%.4f" flag is pretty close but it doesn't eliminate the integer

[FrancescoDiMuro]

@zeenmakr
As stated in the Help file about StringFormat function:

  Quote

Width Specification

The second optional field of the format specification is the width specification. The width argument is a nonnegative decimal integer controlling the minimum number of characters printed. If the number of characters in the output value is less than the specified width, blanks are added to the left or the right of the values — depending on whether the – flag (for left alignment) is specified — until the minimum width is reached. If width is prefixed with 0, zeros are added until the minimum width is reached (not useful for left-aligned numbers).

The width specification never causes a value to be truncated. If the number of characters in the output value is greater than the specified width, or if width is not given, all characters of the value are printed (subject to the precision specification).

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So, you may use one of the various alternatives with all the others String* functions:

#include <StringConstants.au3>


Global $strNumber = "3.1415"

ConsoleWrite("Method 1: " & StringRight($strNumber, StringLen($strNumber) - StringInStr($strNumber, ".")) & @CRLF)
ConsoleWrite("Method 2: " & StringMid($strNumber, StringInStr($strNumber, ".") + 1) & @CRLF)
ConsoleWrite("Method 3: " & StringSplit($strNumber, ".", $STR_NOCOUNT)[1] & @CRLF)
ConsoleWrite("Method 4: " & StringRegExp($strNumber, '^\d+\.(\d*)$', $STR_REGEXPARRAYMATCH)[0] & @CRLF)
ConsoleWrite("Method 5: " & StringRegExpReplace($strNumber, '^\d+\.(\d*)$', '$1') & @CRLF)

[Melba23]

zeenmakr,

Are you saying you want a new functionality for StringFormat which returns only the decimal part of a number? If so then it will never happen as StringFormat (as the name suggests) is about formatting an existing number, not extracting parts of it. And before you bring up the "%**i" method, that is designed to pad out integers with leading zeroes, not to extract the integer value (Int does that quite nicely), as explained in the Help file:

The precision specifies the minimum number of digits to be printed. If the number of digits in the argument is less than precision, the output value is padded on the left with zeros. The value is not truncated when the number of digits exceeds precision.

So just accept that you will need to use another function to achieve your aim - you have been shown many possibilities above.

M23

[zeenmakr]

 

 

  On 6/1/2020 at 6:38 AM, FrancescoDiMuro said:

As stated in the Help file about StringFormat function:

...

so, you may use one of the various alternatives with all the others String* functions:

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thanks for the info and appreciated the examples. any chance to return 0 if number has no decimal points

  On 6/1/2020 at 8:06 AM, Melba23 said:

it will never happen as StringFormat (as the name suggests) is about formatting an existing number

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yea i was hoping, now that make sense. thanks for the info

  On 6/1/2020 at 8:06 AM, Melba23 said:

the "%**i" method, that is designed to pad out integers with leading zeroes

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it does ignore the decimals which was how i got the wrong impression

[jchd]

  On 6/1/2020 at 10:08 AM, zeenmakr said:

it does ignore the decimals which was how i got the wrong impression

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It doesn't ignore anything, on the contrary. Under the hood, AutoIt parses the format string and since the type specifier is i (integer) it automagically invokes Int(argument) for you.
Contrary to C with printf(), AutoIt is smart enough to implicitely perform necessary conversions for you.
StringFormat("%f", 6) yields 6 after converting 6 to a double
StringFormat("%f", ".3zz") yields 0.300000 after converting the string ".3zz" to a double.
StringFormat("%12i", "-.5abc") yields 0 after converting the string "-.5abc" to an int.

In C the first and second calls would likely produce garbage or core dump because 6 would be an integer (typically 32 bit), shorter than a double in memory (64 bit), causing an exception or converting data beyond the actual int boundary.  The third call would definitely yield garbage.

Edited June 1, 2020 by jchd