Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Welcome To Ask or Share your Answers For Others

Categories

0 votes
570 views
in Technique[技术] by (71.8m points)

excel - What's the difference between Trim() and Trim$() in VBA?

What is the difference between trim and trim$ in vba? Accidentally today when I used left and trim functions in vba, The compiler said cant find project or library

When I googled it ,On one of the forum I found the user using like these

 vba.trim("string")

He answered to prefix with vba for the functions. and surprisingly it worked on my pc too.But I found these functions

 trim and trim$ 
 left and left$ 
 leftb and leftb$

I was wondering what is trim and trim$. I wanted to find the difference So I started to google it but the results are for trim ignoring the $ alphabet.

I'm just curious to know about it.I was suspecting that trim is vba function and trim$ is excel sheet function. But we have Application.worksheetfunction to use excel functions right?Could anyone differentiate trim and trim$.

See Question&Answers more detail:os

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
Welcome To Ask or Share your Answers For Others

1 Reply

0 votes
by (71.8m points)

While Issun has answered your question as asked I had enough detail that I wanted to post to provide a further answer as opposed to comment.

The string versions are significantly faster ~ approx 10-30% depending on the data type from my testing over the years. While this is not normally noticeable, it is a performance difference when running on large datasets. So for me it's a no-brainer to use the string rather than variant version.

The sample below works on strings so it shows a speed advantage at the higher end of this range

I have used these functions in combination with variant arrays in both of my public addins as these programs are typically used on entire worksheets even entire workbooks

This link is an excellent reference, for your question, and well beyond

  1. Comparing in vbBinaryCompare rather than vbTextCompare
  2. Optimising empty strings
  3. Testing before replacing
  4. Using built in constants, VbNullString is faster than "", although both will miss a cell that contains ' whereas IsEmpty picks this up
  5. Optimising Loops (break AND into two separate IFs to give an early escape)
  6. Optimising If tests to return the most common Boolean result first rather than run through the Else path (ie a False test may be more appropriate than True)
  7. Using Mid$ on the left hand side of an assignment. From hidden features of VBA

    Sub QuickTimer1()
    Dim lngRow As Long
    Dim dbTime As Double
    Dim strSample As String
    Dim strShort As String
    strSample = "random string"
    dbTime = Timer()
    For lngRow = 1 To 50000000
        strShort = Left$(strSample, 6)
    Next lngRow
    MsgBox Timer() - dbTime
    End Sub
    
    Sub QuickTimer2()
    Dim lngRow As Long
    Dim dbTime As Double
    Dim strSample As String
    Dim strShort As String
    strSample = "random string"
    dbTime = Timer()
    For lngRow = 1 To 50000000
        strShort = Left(strSample, 6)
    Next lngRow
    MsgBox Timer() - dbTime
    End Sub
    

与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
OGeek|极客中国-欢迎来到极客的世界,一个免费开放的程序员编程交流平台!开放,进步,分享!让技术改变生活,让极客改变未来! Welcome to OGeek Q&A Community for programmer and developer-Open, Learning and Share
Click Here to Ask a Question

...