Question

Show the exact output of the following codesegments:(a) for(x=0; x<20; x=x+2)cout<< x << ‘ ‘;cout<< endl ;(b) i=10;for (;i>0; i =i/2;)cout<< i;

Answer 1

Answer:

a)

for(x=0;x<20;x=x+2)

cout<< x << ' ';

cout<< endl ;

Output

0 2 4 6 8 10 12 14 16 18

In this code we are initialing x with 0, check if it is less than 20, then printing the value 0.

Then we increment x value with 2 and check and print again until the x value tends to be equal or more than 20.

C++ program for verifying

#include <iostream>

using namespace std;

int main()

{

   int x;

   for( x=0;x<20;x=x+2)

      cout<< x << ' ';

      cout<< endl ;

   return 0;

}

Output

0 2 4 6 8 10 12 14 16 18

(You can check on any ide for confirmation)

b)

i=10;

for (;i>0; i =i/2;)

cout<< i;

This code will produce error expected ‘)’ before ‘;’ token

  for(;i>0; i =i/2;)

because for loop consist three parameters and in this loop there are 4 parameters.

If we remove semicolon after i/2,

for(;i>0; i =i/2)

then it will produce an output.

10 5 2 1

C++ program for verifying

#include <iostream>

using namespace std;

int main() {

int i=10;

 for(;i>0; i =i/2;)

 cout<< i;

return 0;

}

Output

Error-expected ‘)’ before ‘;’ token

  for(;i>0; i =i/2;)