This is a CST 295 C++

Question

What is the output of each program segment? 

 

 

A. int i = 0;
while (i++ < 30)
{
if ( i % 7 ) continue;
cout << i << " ";
}
cout << endl;

 

B. enum days {SUN, MON, TUE, WED, THU, FRI, SAT};
days research = FRI;
days busiest = THU;
days football = MON;
cout << research – football + busiest << endl;

 

 

 

C. for (i=0; i<5; i++)
{
for (j=0; j<=i; j++)
cout << "X";
cout << endl;
}

 

 

 

D. int a=0, b=1, c=2, temp;
temp=a; a=b; b=temp;
temp=a; a=c; c=temp;
cout << a << " " << b << " " << c << endl;

Answer 1

Hi Brooke,

 

Part A is a loop looking for numbers divisible by seven. If the number is divisible by 7 it is printed. Result: 7, 14, 21, 28.

 

Part B uses the values associated with the positions of the days of the week. SUN = 0, ..., SAT = 6. Research = value of FRI, which is 5. Busiest = value of THU, which is 4, and football = MON, which is 1.

 

Then 5 - 1 + 4 = 8

 

Part C is a double "for" loop with the outer loop varying "i" and the inner loop varying "j". The result of the run is:

 

X

XX

XXX

XXXX

XXXXX

 

Part D uses a temporary variable to hold a value while another variable is set.

 

Line one, temp = a = 0, a = b = 1, b = temp = 0

 

Line two, temp = a = 1, a = c = 2, c = temp = 1

 

Result: a = 2, b = 0, c = 1, output 2 0 1

 

Questions?