LEFT-TRIM function

Removes leading white space, or other specified characters, from a CHARACTER or LONGCHAR expression.


LEFT-TRIM ( `expression` [ , `trim-chars` ] )

An expression (a constant, field name, variable name, or expression) whose value is a CHARACTER or LONGCHAR. If expression is a case-sensitive variable, the AVM performs a case-sensitive trim. If expression is a LONGCHAR, the result is in the same code page.

A character expression that specifies the characters to be trimmed from expression. If you do not specify trim-chars, the LEFT-TRIM function removes spaces, tabs, line feeds, and carriage returns.

The following example shows the effect of the TRIM, LEFT-TRIM, and RIGHT-TRIM functions on a string value:

r-ltrim.p
DEFINE VARIABLE ix AS INTEGER NO-UNDO. DEFINE VARIABLE txt AS CHARACTER NO-UNDO FORMAT "X(26)" INITIAL "*** This is a test **". DEFINE BUTTON b_left LABEL "Left Trim". DEFINE BUTTON b_right LABEL "Right Trim". DEFINE BUTTON b_trim LABEL "Trim". DEFINE BUTTON b_quit LABEL "Quit" AUTO-ENDKEY. DEFINE FRAME butt-frame txt ix LABEL "String Length" SKIP(2) b_left b_right b_trim b_quit WITH CENTERED TITLE "Original Text String". DEFINE FRAME trimed-frame txt LABEL "Trimed Text" ix LABEL "Length" WITH CENTERED. ON CHOOSE OF b_trim, b_right, b_left IN FRAME butt-frame DO: FRAME trimed-frame:TITLE = "Data After " + SELF:LABEL. DISPLAY TRIM(txt, " ") WHEN SELF:LABEL = "Trim" @ txt LENGTH(TRIM(txt, "* ")) WHEN SELF:LABEL = "Trim" @ ix LEFT-TRIM(txt,"* ") WHEN SELF:LABEL = "Left Trim" @ txt LENGTH(*LEFT-TRIM(txt," ")*) WHEN SELF:LABEL = "Left Trim" @ ix RIGHT-TRIM(txt, " ") WHEN SELF:LABEL = "Right Trim" @ txt LENGTH(RIGHT-TRIM(txt, "* ")) WHEN SELF:LABEL = "Right Trim" @ ix WITH FRAME trimed-frame. END. ENABLE b_left b_right b_trim b_quit WITH FRAME butt-frame. ix = LENGTH(txt). DISPLAY txt ix WITH FRAME butt-frame. WAIT-FOR CHOOSE OF b_quit IN FRAME butt-frame.

r-ltrim.p

DEFINE VARIABLE ix  AS INTEGER   NO-UNDO. 
DEFINE VARIABLE txt AS CHARACTER NO-UNDO FORMAT "X(26)"  
  INITIAL "***** This is a test *****". 
DEFINE BUTTON b_left  LABEL "Left Trim". 
DEFINE BUTTON b_right LABEL "Right Trim". 
DEFINE BUTTON b_trim  LABEL "Trim".  
DEFINE BUTTON b_quit  LABEL "Quit" AUTO-ENDKEY.  
DEFINE FRAME butt-frame 
  txt ix LABEL "String Length" SKIP(2) 
  b_left b_right b_trim b_quit 
WITH CENTERED TITLE "Original Text String". 
DEFINE FRAME trimed-frame 
  txt LABEL "Trimed Text" 
  ix  LABEL "Length" 
WITH CENTERED. 
ON CHOOSE OF b_trim, b_right, b_left IN FRAME butt-frame DO: 
  FRAME trimed-frame:TITLE = "Data After " + SELF:LABEL. 
  DISPLAY TRIM(txt, "* ") WHEN SELF:LABEL = "Trim" @ txt 
    LENGTH(TRIM(txt, "* ")) WHEN SELF:LABEL = "Trim" @ ix 
    LEFT-TRIM(txt,"* ") WHEN SELF:LABEL = "Left Trim" @ txt 
    LENGTH(LEFT-TRIM(txt,"* ")) WHEN SELF:LABEL = "Left Trim" @ ix 
    RIGHT-TRIM(txt, "* ") WHEN SELF:LABEL = "Right Trim" @ txt 
    LENGTH(RIGHT-TRIM(txt, "* ")) WHEN SELF:LABEL = "Right Trim" @ ix 
  WITH FRAME trimed-frame. 
END. 
        
ENABLE b_left b_right b_trim b_quit WITH FRAME butt-frame. 
ix = LENGTH(txt). 
DISPLAY txt ix WITH FRAME butt-frame. 
WAIT-FOR CHOOSE OF b_quit IN FRAME butt-frame.

The LEFT-TRIM function is similar to the TRIM function except that it trims characters only from the left end of the string.

If expression is a case-sensitive field or variable, then trim-chars is also as case sensitive. Otherwise, trim-chars is not case sensitive.

The LEFT-TRIM function is double-byte enabled. The specified expression and trim-chars arguments can contain double-byte characters. LEFT-TRIM does not remove double-byte space characters by default.