Gambas/String Manipulation

From Wikibooks, open books for an open world
< Gambas
Jump to: navigation, search

String Concatenation[edit]

The concatenation operator represented by an ampersand symbol is used to join two strings together:

 DIM bestclub AS String
 bestclub = "Liverpool" & " Football Club"    ' Liverpool Football Club

The addition operator cannot be used to concatenate strings[edit]

In gambas, unlike traditional basic, the plus symbol cannot be used as concatenation operator. If an attempt is made to use a plus symbol for this purpose, a type mismatch error will occur when an attempt is made to run the program:

 ' This does not work in gambas
 PRINT "I have 3 cats" + " and 2 dogs"    ' You cannot concatenate strings by using a plus symbol

Concatenation combination assignment operator[edit]

The concatenation combination assignment operator represented by a andequals symbol, can also be used to concatenate strings:

 DIM breakfast AS String
 breakfast = "bacon"
 breakfast &= " and eggs"    ' breakfast = breakfast & " and eggs" (using the andequals symbol)

Search and Replace[edit]

hello i have made a try to search in a text file -two function : 1- search by line and column 2-search by pos

-first function returns an array with results it will be for example like this ["1,12" , "2,1"] , the first element is the line the second is the column

-second function returns also an array but single one ex:[1,2,45,455] every element is the string pos


here you are ! :

AUTHOR: abom
MAIL: abom@linuxac.org
 
----
 
STATIC PUBLIC SUB searchfile(filename AS String, strser AS String) AS String[] 
 
  DIM icounter AS Integer, fn AS stream, ln AS String, wpos AS Integer, rstr AS NEW String[]
  DIM spos AS Integer
  icounter = 0
 
  IF Exist(filename) THEN 
 
     fn = OPEN filename FOR READ
 
      WHILE NOT Eof(fn) 
 
        LINE INPUT #fn, ln
        icounter = icounter + 1
          IF strser = "" THEN RETURN 
          spos = 0
          wpos = 0
          DO
           wpos = InStr(ln, strser, spos, gb.Text) 
 
          IF wpos <> 0 THEN 
             spos = wpos + Len(strser)
             rstr.add(icounter & "," & wpos) 
          END IF
          LOOP UNTIL (wpos = 0) 
      WEND
 
  END IF
  RETURN rstr 
 
END
----
STATIC PUBLIC SUB searchfilebypos(filename AS String, strser AS String) AS String[]
 
  DIM icounter AS Integer, fn AS stream, txt AS String, wpos AS Integer, rstr AS NEW String[]
  DIM spos AS Integer
  icounter = 0
 
  IF Exist(filename) THEN 
       wpos = 0 
       spos = 0
 
       txt = file.Load(filename)
 
       IF strser = "" THEN RETURN 
       DO  
 
           wpos = InStr(txt, strser, spos, gb.Text) 
 
          IF wpos <> 0 THEN 
             spos = wpos + Len(strser)  
             rstr.add(wpos) 
          END IF
 
       LOOP UNTIL (wpos = 0)
  END IF
  RETURN rstr 
 
END