Function Homework

1. Show what is printed by the following program.

#include <iostream.h>

int mix(int a, int& b);

void main()

{

int k = 4, p = 4, ans;

ans = mix(k,p);

cout<<"k = "<< k <<" p = " << p << " ans = " <<ans<<endl;

k = 3

ans = mix(p,k);

cout<<"k = " << k <<" p = " << p << " ans = " <<ans<<endl;

}

int mix(int a, int& b)

{

int j, sum = 0;

b = 3;

for (j = 1; j <= a; j++)

sum += j * b;

cout<< endl <<"in mix: a = "<< a <<" b = "

<< b << " sum = " << sum << endl;

return sum;

}

2. Answer each of the following questions based on the following C++ program. Show how the variables change value.

#include <iostream.h>

void fun(int& , int );

float num = 3.2;

void

main()

{

int p, q, r;

p = 5;

q = 10;

r = 15;

cout << "In main: num is " << num << endl;

cout << "In main: p = " << p << " q = " << q

<< " r = " << r << endl;

fun(r,p);

cout << "In main: p = " << p << " q = " << q

<< " r = " << r << endl;

cout << "In main: num is " << num << endl;

}

void

fun(int& m, int n)

{

int o;

++n;

o = n + m;

++m;

cout << "In fun: num is " << num << endl;

cout << "In fun: m = " << m << " n = " << n

<< " o = " << o << endl;

num = 22.4;

cout << "In fun: num is " << num << endl;

}

a) The variable that is global to both main and fun is _________.

b) The variable local to fun is ______________________________.

c) The reference parameter in fun is?_____________________________

d) What is printed by the above program?

3. Show exactly what is printed by the following program.

#include <iostream.h>

void sub (int m, int n);

void main( )

{

int p, q, r;

p = 5;

q = 10;

r = 15;

cout << "\nIn main: p = " << p <<

" q = " << q << " r = " << r;

sub(r, p);

cout << "\nIn main: p = " << p

<< " q = " << q << " r = " << r;

sub(q, r);

cout << "\nIn main: p = " << p << "

q = " << q << " r = " << r;

}

void sub (int m, int n)

{

int o;

n++;

o = m + 2;

m++;

cout << "\nIn sub: m = " << m <<

" n = " << n << " o = " << o;

}