trim function

stefanobusetto

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• Feb 27, 2012

• #1

i think the trim function doesn't work properly
the function should trim the spaces at the end of a string
but it also trims the characters with ascii code below 32
here is the sample code:

B4X:

Dim s As String
Dim t As String
Dim j As Int

s = "" 
For j = 1 To 10
    s = s & Chr(j)
Next
t = s.Trim

Log ( "source string" )
For j = 0 To s.Length - 1
    Log ( "index = " & j & " ascii = " & Asc ( s.CharAt(j) ) )
Next

Log ( "trimmed string" )
For j = 0 To t.Length - 1
    Log ( "index = " & j & " ascii = " & Asc ( t.CharAt(j) ) )
Next

program output:
source string
index = 0 ascii = 1
index = 1 ascii = 2
index = 2 ascii = 3
index = 3 ascii = 4
index = 4 ascii = 5
index = 5 ascii = 6
index = 6 ascii = 7
index = 7 ascii = 8
index = 8 ascii = 9
index = 9 ascii = 10
trimmed string
(no output)

tanks

 

Last edited by a moderator: Feb 27, 2012

Erel

B4X founder

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• Feb 27, 2012

• #2

Trim removes all the characters that are considered as white space characters. This includes all characters with code point smaller than 21.

 

stefanobusetto

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• Mar 1, 2012

• #3

tanks

but i need e function that removes only the spaces

 

klaus

Expert

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• Mar 1, 2012

• #4

B4X:

t = t.Replace(" ", "")

Best regards.

 

stefanobusetto

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• Mar 1, 2012

• #5

very tanks

 

stefanobusetto

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• Mar 1, 2012

• #6

very tanks anyway

the spaces at the end i mean
i did it at the end

Do While s.EndsWith ( " " )
s = s.SubString2 ( 0 , s.Length - 1 )
Loop

 

J

Jost aus Soest

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• Mar 29, 2012

• #7

stefanobusetto said:

Do While s.EndsWith ( " " )
s = s.SubString2 ( 0 , s.Length - 1 )
Loop

Click to expand...

I would prefer using this function:

B4X:

Sub RTrimSpaces(s As String) As String

  Dim i As Int

  For i = s.Length - 1 To 0 Step -1
    If s.CharAt(i) <> " " Then Exit
  Next'i
  Return s.SubString2(0, i + 1)

End Sub

Advantage: It's faster and uses less ressources, because this sub builds a new string only one time.

 

stefanobusetto

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• Mar 29, 2012

• #8

:sign0098:
thanks

 

J

Jost aus Soest

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• Mar 29, 2012

• #9

stefanobusetto said:

thanks

Click to expand...

Di niente!

 

N

nicodh

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Longtime User

• Apr 13, 2012

• #10

Hi Erel, I'm trying to use trim, and it seems it does not work cleaning white spaces.

Example:
Dim test As String
test="yaw Deadband"
test=test.ToLowerCase ' test becomes "yaw deadband"
test=test.Trim 'test still is yaw deadband when it should be yawdeadband

Am I right?

 

klaus

Expert

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Longtime User

• Apr 13, 2012

• #11

According to the help of the Trim function:
Returns a copy of the original string without any leading or trailing white spaces.

But you want to remove spaces in the string.
You should use:

B4X:

test=test.Replace(" ", "")

Best regards.

 

N

nicodh

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• Apr 13, 2012

• #12

Reading your comment just realize what it meant, and it was my mistake. I use replace for doing that.

I should read better the help... Sometimes i feel like a dork, and the rest of the time I am.

Thanks a lot!

 

R

Roger Garstang

Well-Known Member

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• Apr 26, 2012

• #13

Usually when I read whitespace I expect it to mean Space, tab, and possibly CRLF and nul chars. The other chars are control chars not whitespace.

 

C

ciarli

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• Jan 11, 2015

• #14

I'd like to have three functions: ltrim for the left spaces, rtrim for the right spaces and trim for all spaces, also the internal.

 

Erel

B4X founder

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• Jan 12, 2015

• #15

This is an old thread. Please start a new thread. Feature requests should be posted in the wishlist forum.