%LEN Function

%Len built-in function can be used to get the length of a program defined variable or database variable defined as "Varying". It can also be used to set the current length of such fields.

%Len is also supported for fixed-length fields or expressions.

%Len (Expression)

Parts

Expression: Required. The expression to which the %Len function will apply.

Remarks

When used on the left-hand side of an expression, this function sets the current length of a varying field. If the set length is greater than the current length, the characters in the field between the old length and the new length are set to blanks. A varying field length can then be read and changed at run-time using %Len ( FieldName ).

The following are rules to follow when using %Len:

The maximum length you can specify is the length that was specified for that field when declaring the field (DCLFLD). (The maximum digits for all fixed demimal numbers is 18). A run-time error will occur if the maximum length is exceeded.

1. By assigning a string of Length X - the length of the field is changed to X.

// Given an externally described varying file of length 10:
   City = "Hello" msgbox %Len( City )  // This shows a msgbox with 5, the length of the field.

2. When increasing the length of the field from X to Y, the ( Y-X ) characters of the field are initialized to spaces.

// Given an externally described varying field of length 10:
   City = "Hello"        // This from example above changes the len to 5
   %Len( City ) = 2      // City would look like "He" in Quickwatch
   %Len( City ) = 5      // Now City Should look like "He " in Quickwatch.

Using %Len at Compile-Time

%LEN can be used to define the length of a variable based upon the defined length of another variable or data structure. The basis variable must be defined prior in the code to the use of %Len. The basis variable must also be within the same scope as the using variable.

dclds MyDS
      dclDSFld    DS1      Len( 5,0 )
      dclDSFld    DS2      Len( 25 )
      
  dclfld     X     len( 3,2 )
  dclfld     Y     Len( %len(X),1 )    // Len( 3,1 )
  dclfld     Z     Len( %len(Y),3 )    // Len( 3,3 )
  dclfld     D     Len( %Len(MyDS))    // Len( 30 )

Example

%Len ( FieldName ) = 30 // Sets the length of the FieldName field to 30
Length = %Len ( FieldName ) // Sets the length to the length of the FieldName field

%LEN Function - Get or Set Length

Parts

Remarks

Example

See Also