parameter passing
play

Parameter Passing 7 January 2019 OSU CSE 1 Connecting Caller and - PowerPoint PPT Presentation

Feb 10, 2024 •127 likes •430 views

Parameter Passing 7 January 2019 OSU CSE 1 Connecting Caller and Callee When you call a method, how are the arguments connected to the formal parameters ? When the called method body returns , how are results communicated back to the

  1. Parameter Passing 7 January 2019 OSU CSE 1

  2. Connecting Caller and Callee • When you call a method, how are the arguments connected to the formal parameters ? • When the called method body returns , how are results communicated back to the code that called the method? 7 January 2019 OSU CSE 2

  3. Example: GCD • Suppose we have a static method gcd that computes and returns the greatest common divisor (GCD) of two int s: public static int gcd( int i, int j) { ... } • For example: – GCD(24,80) = 8 – GCD(24,24) = 24 7 January 2019 OSU CSE 3

  4. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... int a, b; ... int c = gcd(a, b); 7 January 2019 OSU CSE 4

  5. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; This is the method gcd that is } being called; i and j are its formal parameters . ... int a, b; ... int c = gcd(a, b); 7 January 2019 OSU CSE 5

  6. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; This is a fragment of the calling } program; a and b are the arguments to this call of gcd . ... int a, b; ... int c = gcd(a, b); 7 January 2019 OSU CSE 6

  7. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; Suppose the solid red arrow } indicates where program flow-of- control has taken us so far. ... int a, b; ... int c = gcd(a, b); 7 January 2019 OSU CSE 7

  8. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... int a, b; ... int c = gcd(a, b); 7 January 2019 OSU CSE 8

  9. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... int a, b; ? ? ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 9

  10. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 10

  11. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } The call to gcd begins ... ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 11

  12. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ? ? ... i j return k; } ... so the formal parameters are effectively declared ... ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 12

  13. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 24 80 ... i j return k; } ... and the argument values are copied to initialize them. ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 13

  14. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 24 80 ... i j return k; } Execution of the calling program is “paused” at the point of the call… ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 14

  15. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 24 80 ... i j return k; } … and control is transferred to the beginning of the method body. ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 15

  16. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 24 80 ... i j return k; The scope of these variables } is the calling program where they are declared. ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 16

  17. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 24 80 ... i j return k; The scope of these variables } is the method body where they are declared. ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 17

  18. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 24 80 1 ... i j k return k; } ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 18

  19. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 0 8 8 ... i j k return k; } ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 19

  20. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 0 8 8 ... i j k return k; } The return statement immediately ends execution of method body… ... int a, b; 24 80 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 20

  21. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; 0 8 8 ... i j k return k; } ... so the returned value is copied back to the calling program … ... int a, b; 24 80 8 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 21

  22. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... and the method body has finished, so its variables go away. ... int a, b; 24 80 8 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 22

  23. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; Note that the values of the formal } parameters are not copied back to the arguments! ... int a, b; 24 80 8 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 23

  24. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } Execution of the calling program “resumes” in mid-statement ... ... int a, b; 24 80 8 ... a b int c = gcd(a, b); 7 January 2019 OSU CSE 24

  25. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... and the value that was returned by the call is assigned to c . ... int a, b; 24 80 8 ... a b c int c = gcd(a, b); 7 January 2019 OSU CSE 25

  26. How Calls Work In Java public static int gcd( int i, int j) { int k = 1; ... return k; } ... int a, b; 24 80 8 ... a b c int c = gcd(a, b); 7 January 2019 OSU CSE 26

  27. Connecting Caller and Callee • When you call a method, how are the arguments connected to the formal parameters ? – The argument values are copied into the formal parameters to initialize them • When the called method body returns , how are results communicated back to the code that called the method? – Only the returned value is copied back to the caller; the formal parameters are simply “lost” 7 January 2019 OSU CSE 27

  28. Names for This? • Parameter-passing mechanism of Java: – May be termed call-by-copying because argument values are copied into formal parameters – May be termed call-by-value because argument values are copied into formal parameters • There are other ways it might have been done (and is done in some languages) 7 January 2019 OSU CSE 28

  29. Tracing Over a Call Code State a = 24 b = 80 int c = gcd(a, b); a = 24 b = 80 c = 8 7 January 2019 OSU CSE 29

Recommend

Parameter passing Looked at lisps conventional parameter passing mechanism: where

Parameter passing Looked at lisps conventional parameter passing mechanism: where

Parameter passing Looked at lisps conventional parameter passing mechanism: where parameters passed in the order listed, by value, and all parameters are mandatory Several alternatives available: Optional parameters with default

184 views • 14 slides
Subroutines Parameters Passing Parameter Passing p. 1/7 Methods of Passing Parameters In

Subroutines Parameters Passing Parameter Passing p. 1/7 Methods of Passing Parameters In

Systems Architecture Subroutines Parameters Passing Parameter Passing p. 1/7 Methods of Passing Parameters In Registers Must document registers used Limited number of registers Uses fast on-chip registers Dictates register usage

462 views • 14 slides
Parameter Passing and Pointers Parameter passing and functions I: reference parameters

Parameter Passing and Pointers Parameter passing and functions I: reference parameters

Parameter Passing and Pointers Parameter Passing and Pointers Outline Parameter Passing and Pointers Parameter passing and functions I: reference parameters call-by-value vs call-by-name call-by-name by using reference parameters Martin Emms

60 views • 4 slides
Parameter Passing Styles Dr. Mattox Beckman University of Illinois at Urbana-Champaign

Parameter Passing Styles Dr. Mattox Beckman University of Illinois at Urbana-Champaign

Introduction Parameter Passing Styles Parameter Passing Styles Dr. Mattox Beckman University of Illinois at Urbana-Champaign Department of Computer Science Introduction Parameter Passing Styles Objectives You should be able to... The

465 views • 15 slides
PASSING POINTERS TO FUNCTIONS CSSE 120 Rose-Hulman Institute of Technology Parameter Passing

PASSING POINTERS TO FUNCTIONS CSSE 120 Rose-Hulman Institute of Technology Parameter Passing

POINTERS IN C, PASSING POINTERS TO FUNCTIONS CSSE 120 Rose-Hulman Institute of Technology Parameter Passing Styles Most programming languages offer several means of passing parameters. We have seen pass-by-value, in which the

415 views • 22 slides
6. Parameter Passing Parameter Passing CS 381 Spring 2016 Example (Formal) Parameter void

6. Parameter Passing Parameter Passing CS 381 Spring 2016 Example (Formal) Parameter void

CS 381 Spring 2016 6. Parameter Passing Parameter Passing CS 381 Spring 2016 Example (Formal) Parameter void f(int x, int y) { y := x+1 }; x := 3; What is the value of z? z := 1; f(2*x,z); ... it depends on the parameter

244 views • 22 slides
Scope and Parameter Passing 1 / 19 Outline Overview Naming and scope Function/procedure calls

Scope and Parameter Passing 1 / 19 Outline Overview Naming and scope Function/procedure calls

Scope and Parameter Passing 1 / 19 Outline Overview Naming and scope Function/procedure calls Static vs. dynamic scope Parameter passing schemes 2 / 19 Review of naming Most languages provide a way to name and reuse stuff Naming concepts

206 views • 19 slides
Code Generation & 1. Allocating temporaries in the activation record Parameter Passing

Code Generation & 1. Allocating temporaries in the activation record Parameter Passing

Lecture Outline Code Generation & 1. Allocating temporaries in the activation record Parameter Passing Lets optimize our code generator a bit 2. A deeper look into calling sequences Caller/Callee responsibilities 3. Parameter

268 views • 13 slides
Code Generation & Parameter Passing Lecture Outline 1. Allocating temporaries in the

Code Generation & Parameter Passing Lecture Outline 1. Allocating temporaries in the

Code Generation & Parameter Passing Lecture Outline 1. Allocating temporaries in the activation record Lets optimize our code generator a bit 2. A deeper look into calling sequences Caller/Callee responsibilities 3. Parameter

639 views • 50 slides
Subroutines and Parameter Passing ECE2893 Lecture 5 ECE2893 Subroutines and Parameter Passing

Subroutines and Parameter Passing ECE2893 Lecture 5 ECE2893 Subroutines and Parameter Passing

Subroutines and Parameter Passing ECE2893 Lecture 5 ECE2893 Subroutines and Parameter Passing Spring 2011 1 / 10 C/C++ Subroutines (Functions) ECE2893 Subroutines and Parameter Passing Spring 2011 2 / 10 C/C++ Subroutines (Functions)

888 views • 62 slides
Last Class Parameter passing Call-by-value vs call-by-reference Inheritance Public,

Last Class Parameter passing Call-by-value vs call-by-reference Inheritance Public,

Last Class Parameter passing Call-by-value vs call-by-reference Inheritance Public, package, protected, private Overriding Overloading Constru.... Constructors Every class comes with a default constructor with no

318 views • 11 slides
Midterm Review Tevfik Ko ar Louisiana State University October 14 th , 2008 1 2 Parameter

Midterm Review Tevfik Ko ar Louisiana State University October 14 th , 2008 1 2 Parameter

CSC 4304 - Systems Programming Parameter Passing in C Fall 2008 Lecture - XII Midterm Review Tevfik Ko ar Louisiana State University October 14 th , 2008 1 2 Parameter Passing in C Pointer Arithmetic 3 4 Pointer Arithmetic Pointer

356 views • 9 slides
Compressive Parameter Estimation via Approximate Message Passing Marco F. Duarte Joint work

Compressive Parameter Estimation via Approximate Message Passing Marco F. Duarte Joint work

Compressive Parameter Estimation via Approximate Message Passing Marco F. Duarte Joint work with Shermin Hamzehei IEEE ICASSP - April 22 2015 Concise Signal Structure Sparse signal: only K out of N n n x = coefficients

484 views • 24 slides
Parameter Passing Modes a 5 Alternative evaluation schemes b 10 for eager

Parameter Passing Modes a 5 Alternative evaluation schemes b 10 for eager

11/1/15 control link Parameter Passing Modes a 5 Alternative evaluation schemes b 10 for eager evaluation control link Eager evaluation and parameter passing: by value vs. by

303 views • 5 slides
Programming Abstractions Week 9-1: Dynamic Bindings and Parameter Passing Stephen Checkoway

Programming Abstractions Week 9-1: Dynamic Bindings and Parameter Passing Stephen Checkoway

Programming Abstractions Week 9-1: Dynamic Bindings and Parameter Passing Stephen Checkoway (define f (let ([x 1] [y 2]) ( (z) (if z x y)))) What is the value of (f 10)? A. This is a run-time error because 10 isn't a boolean B. This is some

507 views • 39 slides
Parameters Chapter Eighteen Modern Programming Languages, 2nd ed. 1 Parameter Passing formal

Parameters Chapter Eighteen Modern Programming Languages, 2nd ed. 1 Parameter Passing formal

Parameters Chapter Eighteen Modern Programming Languages, 2nd ed. 1 Parameter Passing formal parameters int plus(int a, int b) { return a+b; method body } int x = plus(1,2); actual parameters method call How are parameters passed?

679 views • 50 slides
Passing Objects In Member Functions Object Parameter class Bank { ... int Withdraw(int id,

Passing Objects In Member Functions Object Parameter class Bank { ... int Withdraw(int id,

Passing Objects In Member Functions Object Parameter class Bank { ... int Withdraw(int id, const Money &money); int Deposit(int id, const Money &money); ... }; Why pass the object by reference? Object Parameter class Bank {

1.09k views • 11 slides
Advanced Code Generation Parameter Passing Short-circuit boolean evaluation Arrays

Advanced Code Generation Parameter Passing Short-circuit boolean evaluation Arrays

Advanced Code Generation Parameter Passing Short-circuit boolean evaluation Arrays Classes Advanced Code Generation Parameter Passing Short-circuit boolean evaluation Arrays Classes Im away this

122 views • 8 slides
POINTERS IN C, PASSING POINTERS TO FUNCTIONS CSSE 120Rose-Hulman Institute of Technology

POINTERS IN C, PASSING POINTERS TO FUNCTIONS CSSE 120Rose-Hulman Institute of Technology

POINTERS IN C, PASSING POINTERS TO FUNCTIONS CSSE 120Rose-Hulman Institute of Technology Parameter Passing in Python In Python, parameters are passed two ways: For numbers, a copy of the number is passed to the function For

325 views • 14 slides
MPI - Message Passing Interface MPI is the mostly used message passing-standard By

MPI - Message Passing Interface MPI is the mostly used message passing-standard By

MPI - Message Passing Interface MPI is the mostly used message passing-standard By using MPI you obtain portable programs MPI is based on earlier message passing libraries Lecture 7: NX, MPL, PVM, P4, TCGMSH, PARMACS, ...

360 views • 9 slides
Message Passing Concepts Message Passing Model The message passing model is based on the

Message Passing Concepts Message Passing Model The message passing model is based on the

Message Passing Concepts Message Passing Model The message passing model is based on the notion of processes can think of a process as an instance of a running program, together with the programs data In the message passing model,

601 views • 16 slides
Message Passing Programming with MPI Message Passing Programming with MPI 1 What is MPI?

Message Passing Programming with MPI Message Passing Programming with MPI 1 What is MPI?

Message Passing Programming with MPI Message Passing Programming with MPI 1 What is MPI? Message Passing Programming with MPI 2 MPI Forum First message-passing interface standard. Sixty people from forty different organisations.

1.61k views • 113 slides
Parameter passing: call-by-value public class CBV { public static void main(String[] args) {

Parameter passing: call-by-value public class CBV { public static void main(String[] args) {

Parameter passing: call-by-value public class CBV { public static void main(String[] args) { int i=9; System.out.println("Initially : " + i); changeI(i); System.out.println("Finally : " + i); } private static void

430 views • 17 slides
Message-Passing Programming with MPI Message-Passing Concepts Overview This lecture will

Message-Passing Programming with MPI Message-Passing Concepts Overview This lecture will

Message-Passing Programming with MPI Message-Passing Concepts Overview This lecture will cover message passing model SPMD communication modes collective communications Programming Models Message-Passing Serial Programming

406 views • 28 slides

More recommend