Modifying Action Diagrams › Understanding Built-In Functions › Considerations for Date and Time Field Types › Substring

Substring

The *SUBSTRING built-in function allows you to extract a portion of a character string from one field and insert it into another.

There are five parameters for this function type:

• Three input parameters which are a character string, *String 1, denoting the character substring that is to be extracted, the *From position field denoting the position from which the extraction of the character string occurs, and the *For length field denoting the length of the character substring to be extracted.
• Two output parameters which are the *Resulting string into which the extracted substring is inserted and a *Return code to determine the result of the attempted insertion. Return code is an implied parameter and is set to condition *NORMAL when insertion completes successfully.

The *For Length field has two special conditions: *FLDLEN which indicates that the entire length of the field or constant is to be used and *END which means that the extraction occurs from the position of the *From position field to the end of the field or constant.

CA 2E implements the *SUBSTRING built-in function in RPG using the SUBSTR statement in COBOL using the STRING statement. For COBOL 85, it uses a reference modification and for COBOL, 74 it is uses string manipulation.

The following is an example of a substring function.

This example extracts the first six characters from the Full Name field.

The following diagram contains the parameters for the previous example.