Difference between revisions of "Multi-Paradigm Programming and Scripting"
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A programming language that supports reflection allows its programs to have runtime access to their types and structure and to be able to dynamically modify their behavior | A programming language that supports reflection allows its programs to have runtime access to their types and structure and to be able to dynamically modify their behavior | ||
Revision as of 17:33, 2 November 2019
- Improved background for choosing appropriate languages
Contents
Compilation vs Interpretation
Phases of Compilation
C++ Inheritance
https://www.w3schools.com/cpp/cpp_inheritance.asp
https://www.tutorialspoint.com/cplusplus/cpp_interfaces.htm
Difference Between Static and Dynamic Binding
https://techdifferences.com/difference-between-static-and-dynamic-binding.html
Reflection
A programming language that supports reflection allows its programs to have runtime access to their types and structure and to be able to dynamically modify their behavior
- The types and structure of a program are called
metadata
- The process of a program examining its metadata is called
introspection
- Interceding in the execution of a program is called
intercession
Uses of reflection for software tools:
- Class browsers need to enumerate the classes of a program
- Visual IDEs use type information to assist the developer in building type correct code
- Debuggers need to examine private fields and methods of classes
- Test systems need to know all of the methods of a class
Downsides of Reflection:
- Performance costs
- Exposes private fields and methods
- Voids the advantages of early type checking
- Some reflection code may not run under a security manager, making code nonportable
Reflection in Java
- Limited support from
java.lang.Class
- Java runtime instantiates an instance of
Class
for each object in the program
- The
getClass
method ofClass
returns theClass
object of an object
float[] totals = new float[100];
Class fltlist = totals.getClass();
Class stg = "hello".getClass();
- If there is no object, use class field:
Class stg = String.class;
- Class has four useful methods:
getMethod
searches for a specific public method of a classgetMethods
returns an array of all public methods of a classgetDeclaredMethod
searches for a specific method of a classgetDeclaredMethods
returns an array of all methods of a class- The
Method
class defines the invoke method, which is used to execute the method found bygetMethod