LEFT-TRIM function

Removes leading white space, or other specified characters, from a CHARACTER or LONGCHAR expression. The data type of the returned value matches the data type of the expression passed to the function.

Syntax

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

expression

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.

trim-chars

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.

Example

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.

Notes

• 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.

See also

RIGHT-TRIM function, TRIM function