Difference between revisions of "Multi-Paradigm Programming and Scripting"
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− | * Improved background for choosing appropriate languages | + | *Improved background for choosing appropriate languages |
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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 | ||
− | * The types and structure of a program are called <code>'''metadata'''</code> | + | *The types and structure of a program are called <code>'''metadata'''</code> |
− | * The process of a program examining its metadata is called <code>'''introspection'''</code> | + | *The process of a program examining its metadata is called <code>'''introspection'''</code> |
− | * Interceding in the execution of a program is called <code>'''intercession'''</code> | + | *Interceding in the execution of a program is called <code>'''intercession'''</code> |
'''Uses of reflection for software tools:''' | '''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 | + | *Class browsers need to enumerate the classes of a program |
− | * Debuggers need to examine private fields and methods of classes | + | *Visual IDEs use type information to assist the developer in building type correct code |
− | * Test systems need to know all of the methods of a class | + | *Debuggers need to examine private fields and methods of classes |
+ | *Test systems need to know all of the methods of a class | ||
<br /> | <br /> | ||
===Reflection in Java=== | ===Reflection in Java=== | ||
− | |||
− | * Java runtime instantiates an instance of <code>Class</code> for each object in the program | + | *Limited support from <code>java.lang.Class</code> |
+ | |||
+ | *Java runtime instantiates an instance of <code>Class</code> for each object in the program | ||
+ | |||
+ | *The <code>getClass</code> method of <code>Class</code> returns the <code>Class</code> object of an object | ||
+ | |||
+ | ::<code>float[] totals = new float[100];</code> | ||
+ | ::<code>Class fltlist = totals.getClass();</code> | ||
+ | ::<code>Class stg = "hello".getClass();</code> | ||
− | * | + | *If there is no object, use class field: |
− | |||
− | |||
− | |||
− | + | ::<code>Class stg = String.class;</code> | |
− | :: <code>Class stg = String.class;</code> | + | :* '''Class has four useful methods:''' <blockquote><code>getMethod</code> searches for a specific public method of a class</blockquote><blockquote><code>getMethods</code> returns an array of all public methods of a class</blockquote><blockquote><code>getDeclaredMethod</code> searches for a specific method of a class</blockquote><blockquote><code>getDeclaredMethods</code> returns an array of all methods of a class</blockquote><blockquote>The <code>Method</code> class defines the invoke method, which is used to execute the method found by <code>getMethod</code></blockquote><br /> |
<br /> | <br /> |
Revision as of 20:37, 30 October 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 in Java
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
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 classThe
Method
class defines the invoke method, which is used to execute the method found bygetMethod