How to replace whole words in a string

[John Kouraklis 94]

Hi,

I am using TStringHelper.Replace to replace substrings in strings but it seems that it does not respect whole words.

 

Anyone knows how to do this with Replace?

 

[Silver Black 23]

2 hours ago, John Kouraklis said:

Hi,

I am using TStringHelper.Replace to replace substrings in strings but it seems that it does not respect whole words.

 

Anyone knows how to do this with Replace?

 

 

I use StringReplace. Eg.:

Result := StringReplace(strText, strOld, strNew, [rfIgnoreCase, rfReplaceAll]);

It's perfect for me, for years no issues yet.

[John Kouraklis 94]

@Silver Black

That's what I use now and sadly does not replace whole words.

 

Eg. in this string 'abc and abc.def' if you want to replace 'abc' whole word only the above and the one from stringhelper will replace both instances of 'abc'

 

 

[Silver Black 23]

10 minutes ago, John Kouraklis said:

@Silver Black

That's what I use now and sadly does not replace whole words.

 

Eg. in this string 'abc and abc.def' if you want to replace 'abc' whole word only the above and the one from stringhelper will replace both instances of 'abc'

 

 

 

If you want to distinguish between words, that for definition are separated by spaces, you have to make a proper function that check occourrences of at least a space before and at least a space after the pattern you want to replace as a word. So it will search for the pattern "abc" then check if before or after there are spaces, if so replace it, otherwise it search for the next occourrence.

[FredS 138]

19 minutes ago, John Kouraklis said:

'abc and abc.def'

 

The code below will return: 'yes, yes.def'

v := TRegEx.Replace('abc, abc.def', '\babc\b', 'yes', [TRegExOption.roIgnoreCase]);

\babc\b

Options: Case insensitive; Exact spacing; Dot doesn’t match line breaks; ^$ match at line breaks; Numbered capture; Skip zero-length matches

Assert position at a word boundary (position preceded or followed—but not both—by an ASCII letter, digit, or underscore) «\b»
Match the character string “abc” literally (case insensitive) «abc»
Assert position at a word boundary (position preceded or followed—but not both—by an ASCII letter, digit, or underscore) «\b»

Created with RegexBuddy

 

[John Kouraklis 94]

@FredS

What I need is to return 'yes, abc.def' 

 

 

[Silver Black 23]

To identify a word, besides of spaces, you should also check for dots, commas, etc. Eg.: "abc." / "abc," / " abc "

 

@FredS  your regEx expressions does the same of my StringReplace. 😉

Edited February 18, 2019 by Silver Black

[John Kouraklis 94]

Yes, but I don't want to write a function from scratch

[toms 29]

Does that function ReplaceWords() work  for you?

 

http://codeverge.com/embarcadero.delphi.general/stringreplace-with-a-whole-word-on/1063318

 

 

 

Edited February 18, 2019 by toms

[FredS 138]

1 hour ago, John Kouraklis said:

What I need is to return 'yes, abc.def' 

 

Then you need to figure out what that logic is, it's not word boundaries:

https://regex101.com/r/bnXElq/1

 

 

[David Schwartz 426]

I use the RegExpr library from years back. It's great. Very easy to set up patterns to detect words.

[John Kouraklis 94]

Thanks for the RegEx suggestions

[limelect 48]

In RX library use RxStrUtils.pas  and use

 

function ReplaceStr(const S, Srch, Replace: string): string; {$IFDEF RX_D9}inline; {$ENDIF}
{ Returns string with every occurrence of Srch string replaced with
  Replace string. }

 

It dose the job