Parameter passing methods

PARAMETER PASSING METHODS

Parameter-passing methods are the ways in which parameters are transmitted to and/or from called subprograms. 

Parameter passing depends on model of subprogram.There are two models for parameter passing-

1. Semantics Models of Parameter Passing

2. Implementation Models of Parameter Passing

1. Semantics Models of Parameter Passing: Formal parameters are characterized by one of three distinct semantics models:

1. They can receive data from the corresponding actual parameter, called in mode.
2. They  can transmit data to the actual parameter, called out mode.
3. They  can do both, called inout mode.

2. Implementation Models of Parameter Passing: This model consist the following ways of parameter passing.

1. Pass by value
2. Pass by reference
3. Pass-by-Result
4. Pass-by-Value-Result
5. Pass-by-Name

1. Pass by value: Value of actual parameter in read only mode is transmitted to formal parameters.

2. Pass by reference: Reference/address of actual parameter  is transmitted to formal parameters.

3. Pass-by-Result: When a parameter is passed by result, no value is transmitted to the subprogram.

4. Pass-by-Value-Result: Pass-by-value-result is an implementation model for inout-mode parameters. Pass-by-value-result is sometimes called pass-by-copy, because the actual

parameter is copied to the formal parameter at subprogram entry and then

copied back at subprogram termination.

5. Pass-by-Name: Pass-by-name is an inout-mode parameter transmission method. In it parameters are passed by name. Implementing a pass-by-name parameter requires a subprogram to be passed to the called subprogram to evaluate the address or value of the formal parameter.

Program examples:

Call by value:

#include <iostream>

using namespace std;

void show(int x)

{

    cout<<x<<endl;

}

int main()

{

    int age = 20;

    show(age);

    show(10);

    return 0;

}

Call by reference:

#include <iostream>

using namespace std;

void show(int *x)

{

    cout<<*x<<endl;

}

int main()

{

    int age = 20;

    show(&age);

    

    return 0;

}

Principles of Programming Languages:

EasyExamNotes.com covered following topics in these notes.

• Language Evaluation Criteria
• Influences on Language Design 
• Language Categories
• Programming Paradigms
• Compilation
• Virtual Machines 
• Programming Environments
• Issues in Language Translation
• Parse Tree 
• Pointer and Reference type
• Concept of Binding
• Type Checking
• Strong typing 
• Sequence control with Expression
• Exception Handling 
• Subprograms
• Fundamentals of sub-programs
• Scope and lifetime of variable
• Static and dynamic scope
• Design issues of subprogram and operations
• Local referencing environments
• Parameter passing methods
• Overloaded sub-programs
• Generic sub-programs 
• Design issues for functions 
• Co routines 
• Abstract Data types
• Abstraction and encapsulation
• Static and Stack-Based Storage management
• Garbage Collection
• OOP in C++
• OOP in Java 
• OOP in C# 
• OOP in PHP
• Concurrency
• Semaphores 
• Monitors
• Message passing
• Java threads 
• C# threads 
• Exception handling 
• Exceptions
• Exception Propagation 
• Exception handler in C++ 
• Exception handler in Java
• Introduction and overview of Logic programming
• Basic elements of Prolog
• Application of Logic programming
• Functional programming languages
• Introduction to 4GL 

Practicals:

• Memory Implementation of 2D Array. 
• Memory Implementation of 3D Array. 
• Implementation of pointers in C++. 
• Write a program in Java to implement exception handling.
• Write a program in C++ to implement call by value parameter passing Method.
• Write a program in C++ to implement call by reference parameter passing Method. 
• Write a program in Java to implement concurrent execution of a job using threads.
• Implement Inheritance in C#.
• Implement Encapsulation in C#.
• Implement static/compiletime Polymorphism in C#.
• Implement dynamic/runtime Polymorphism in C#.

Previous years solved papers:

• PPL|RGPV|May 2018 
• PPL|RGPV|June 2017 

A list of Video lectures

• Click here

References:

1. Sebesta,”Concept of programming Language”, Pearson Edu 
2. Louden, “Programming Languages: Principles & Practices” , Cengage Learning 
3. Tucker, “Programming Languages: Principles and paradigms “, Tata McGraw –Hill. 
4. E Horowitz, "Programming Languages", 2nd Edition, Addison Wesley