comp15111: introduction to architecturesyllabus.cs.manchester.ac.uk/.../lectures/stack2.pdf ·...

COMP15111: Introduction to ArchitectureLecture 10: Methods – Parameters and Variables

Dr. Javier Navaridas

School of Computer Science, University of Manchester

Autumn 2016

COMP15111 Lecture 10 1/33

Lecture 10: You are here

An Example Java Program

Lifespan of Variables in a Running Java Program

COMP15111 Lecture 10 An Example Java Program 2/33

An example Java Program – AgeHistory2

static int presentDay, presentMonth, presentYear;

void printAgeHistory (int person, birthDay, birthMonth, birthYear)int someYear, ageInSomeYear1;

System.out.println(...);... birthYear ... presentYear ... someYear ...

void main(String[] args)int birthDay1, birthMonth1, birthYear1, ...... = Integer.parseInt(args[...]);printAgeHistory(...);

void println(String string)print(string);

write(newline);

void print(String string)write(nextchar);

COMP15111 Lecture 10 An Example Java Program 4/33

An example Java Program – AgeHistory2

static int presentDay, presentMonth, presentYear;

void printAgeHistory (int person, birthDay, birthMonth, birthYear)int someYear, ageInSomeYear1;

System.out.println(...);... birthYear ... presentYear ... someYear ...

void main(String[] args)int birthDay1, birthMonth1, birthYear1, ...... = Integer.parseInt(args[...]);printAgeHistory(...);

void println(String string)print(string);

write(newline);

void print(String string)write(nextchar);

COMP15111 Lecture 10 An Example Java Program 4/33

An example Java Program – AgeHistory2

static int presentDay, presentMonth, presentYear;

void printAgeHistory (int person, birthDay, birthMonth, birthYear)int someYear, ageInSomeYear1;

System.out.println(...);... birthYear ... presentYear ... someYear ...

void main(String[] args)int birthDay1, birthMonth1, birthYear1, ...... = Integer.parseInt(args[...]);printAgeHistory(...);

void println(String string)print(string);

write(newline);

void print(String string)write(nextchar);

COMP15111 Lecture 10 An Example Java Program 4/33

An example Java Program – AgeHistory2

static int presentDay, presentMonth, presentYear;

void printAgeHistory (int person, birthDay, birthMonth, birthYear)int someYear, ageInSomeYear1;

System.out.println(...);... birthYear ... presentYear ... someYear ...

void main(String[] args)int birthDay1, birthMonth1, birthYear1, ...... = Integer.parseInt(args[...]);printAgeHistory(...);

void println(String string)print(string);

write(newline);

void print(String string)write(nextchar);

COMP15111 Lecture 10 An Example Java Program 4/33

An example Java Program – AgeHistory2

static int presentDay, presentMonth, presentYear;

void printAgeHistory (int person, birthDay, birthMonth, birthYear)int someYear, ageInSomeYear1;

System.out.println(...);... birthYear ... presentYear ... someYear ...

void main(String[] args)int birthDay1, birthMonth1, birthYear1, ...... = Integer.parseInt(args[...]);printAgeHistory(...);

void println(String string)print(string);

write(newline);

void print(String string)write(nextchar);

COMP15111 Lecture 10 An Example Java Program 4/33

Lecture 10: You are here

An Example Java Program

Lifespan of Variables in a Running Java Program

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Running AgeHistory2

birthYear1 etc.

presentYear etc.

main starts

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Running AgeHistory2

intString etc.

birthYear1 etc.

presentYear etc.

main calls parseInt (*6)

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Running AgeHistory2

birthYear1 etc.

presentYear etc.

parseInt returns to main

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Running AgeHistory2

someYear etc.

birthYear1 etc.

presentYear etc.

main calls printAgeHistory (*2)

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Running AgeHistory2

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

printAgeHistory calls println (*3?)

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Running AgeHistory2

string etc.

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

println calls print

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Running AgeHistory2

char etc.

string etc.

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

print calls write (*n)

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Running AgeHistory2

string etc.

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

write returns to print

COMP15111 Lecture 10 Lifespan of Variables in a Running Java Program 21/33

Running AgeHistory2

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

print returns to println

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Running AgeHistory2

char etc.

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

println calls write

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Running AgeHistory2

string etc.

someYear etc.

birthYear1 etc.

presentYear etc.

write returns to println

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Running AgeHistory2

someYear etc.

birthYear1 etc.

presentYear etc.

println returns to printAgeHistory

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Running AgeHistory2

birthYear1 etc.

presentYear etc.

printAgeHistory returns to main

COMP15111 Lecture 10 Lifespan of Variables in a Running Java Program 31/33

Running AgeHistory2

presentYear etc.

main finishes

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