Compiling user-defined function definitions
When the compiler encounters a user-defined function definition, it automatically extracts characteristics from the definition. These characteristics together form a function prototype. The function name, returning item data description entry, and parameter data description entries are some of the characteristics gathered.
About this task
When a function invocation is encountered by the compiler in a program or user-defined function definition, the compiler will determine if the arguments and returning item are appropriate. The arguments will be checked against the corresponding formal parameters in a process known as conformance checking. See Conformance of parameters for user-defined functions in the Enterprise COBOL for z/OS® Language Reference.