An [incr Tcl] class definition takes the form shown here. Each of the commands within the class definition are optional and can be listed in any order. The parameters args, init, body, and config are Tcl lists.

class className {
     inherit baseClass....
     constructor args [init] body
     destructor body
     method name [args] [body]
     proc name [args] [body]
     variable varName [init] [config]
     common varName [init]
     public command [arg ...]
     protected command [arg...]
     private command [arg...]
     set varName [value]
     array option [arg ...]
}