Core PHP Programming, Third Edition

6.9. Binding

Other than restricting access, access types also determine which method will be called or which property will be accessed in subclasses that override methods or properties. Linking between function calls and their corresponding function, and between member accesses and the memory location of variables, is called binding.

There are two main types of binding in computer languages—static binding and dynamic binding. Static binding matches references to data structures and the data structures themselves. Static binding occurs during compilation and consequently cannot make use of any runtime information. It matches function calls to function bodies, and it matches variables to their block of memory. Since PHP is a dynamic language, it ...