4GL Built-In Functions and Operators Overview

In 4GL, a function is a named collection of statements that performs a task.

The FUNCTION statement can define functions. 4GL programs can invoke the following types of functions:

• Programmer-defined 4GL functions
• 4GL built-in functions
• SQL built-in functions
• C functions
• ESQL/C functions (if you have the INFORMIX-ESQL/C product)

The FUNCTION program block begins with the FUNCTION keyword and ends with the END FUNCTION keywords. These enclose a program block of the 4GL statements that compose the function; these are executed when the function is invoked. This is the syntax of the FUNCTION statement:

• argument is the name of a formal argument to the function.
• function is the name that you declare for the function.
• statement is an SQL statement or other 4GL statement.

No other FUNCTION, REPORT, nor MAIN program block can be included in a FUNCTION definition, but it can include statements that produce a report, or call a function, or execute a RUN statement that invokes another program.

Syntax of Built-In Functions and Operators

Operators that are represented by non-alphabetic symbols are grouped under the headings Arithmetic Operators and Relational Operators.