Static versus dynamic calls

Calling functions and events

PowerBuilder calls functions and events in three ways, depending on the type of function or event and the lookup method defined.

**Table 6-2: How PowerBuilder calls functions and events**
Type of function	Compiler typing	Comments
Global and system functions	Strongly typed. The function must exist when the script is compiled.	These functions must exist and are called directly. They are not polymorphic, and no substitution is ever made at execution time.
Object functions with STATIC lookup	Strongly typed. The function must exist when the script is compiled.	The functions are polymorphic. They must exist when you compile, but if another class is instantiated at execution time, its function is called instead.
Object functions with DYNAMIC lookup	Weakly typed. The function does not have to exist when the script is compiled.	The functions are polymorphic. The actual function called is determined at execution time.

Specifying static or dynamic lookup

For object functions and events, you can choose when PowerBuilder looks for them by specifying static or dynamic lookup. You specify static or dynamic lookup using the STATIC or DYNAMIC keywords. The DYNAMIC keyword applies only to functions that are associated with an object. You cannot call global or system functions dynamically.