[SOLVED]Check if char exists in a predefined array
lazarus / 62-General

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torbente · 2021-01-11 18:25

Using Lazarus 2.0.10, on win 8.1

Code: Pascal  [Select][+][-]window.onload = function(){var x1 =
document.getElementById("main_content_section"); if (x1) { var x =
document.getElementsByClassName("geshi");for (var i = 0; i
Const:MyArray : array[0..3] of char = ('A','N','S','O'); s : string =
'LWFEUÑOWWÑLKDWE';for counter := 1 to length(s) do   // if s[counter]
exist in MyArray do something
How i can check i s[counter] is valid char in myarray? i could add
another counter to check if s[counter] = MyArray[counter2], but i want
know if there is a simple way to do it.

Thanks.

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Bart · 2021-01-11 18:30

IIRC then fpc trunk allows the "in" operator for that (which
internally will I think use a loop.
If you make MyArray a string then you can use Pos() to determine if a
char is in MyArray.
Internally this uses more optimized code than a simple for loop IIRC,
so it might be faster.

Bart

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ASerge · 2021-01-11 19:56

You can also use sets if the array does not contain "long" characters.
And I would recommend write a separate CharInArray function, and then
choosing it implementation.

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torbente · 2021-01-11 20:36

Thanks for the replys:

The pos function using a string is a great solution!

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Zvoni · 2021-01-12 07:21

The way i do it:
Loop through MyArray (instead of your target-string) and use StrScan
https://www.freepascal.org/docs-html/current/rtl/strings/strscan.html

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PascalDragon · 2021-01-12 07:53

Quote from: Zvoni on January 12, 2021, 08:21:41 amThe way i do it:
Loop through MyArray (instead of your target-string) and use StrScan
https://www.freepascal.org/docs-html/current/rtl/strings/strscan.html

Better use Pos. Pascal strings are allowed to have NUL characters,
while StrScan works on NUL-terminated strings, thus will stop on the
first NUL found.

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Zvoni · 2021-01-12 08:48

Quote from: PascalDragon on January 12, 2021, 08:53:42 amQuote from:
Zvoni on January 12, 2021, 08:21:41 amThe way i do it:
Loop through MyArray (instead of your target-string) and use StrScan
https://www.freepascal.org/docs-html/current/rtl/strings/strscan.html

Better use Pos. Pascal strings are allowed to have NUL characters,
while StrScan works on NUL-terminated strings, thus will stop on the
first NUL found.
PD,
i know that.
That's why i wrote "The way i do it", since i have full control of
"my" strings.....