Output of C programs | Set 61 (Loops)
Prerequisite : Loops in C
Q.1 What is the output of this program?
#include <iostream> using namespace std; int main() { int i, j, var = 'A' ; for (i = 5; i >= 1; i--) { for (j = 0; j < i; j++) printf ( "%c " , (var + j)); printf ( "\n" ); } return 0; } |
Options
a)A B C D E
A B C D E
A B C D E
A B C D E
A B C D E
b)A B C D
A B C D
A B C D
A B C D
c)A B C D
A B C
A B
A
d)A B C D E
A B C D
A B C
A B
A
ans:- d
Explanation :- inner loop iterates for value less than equal to i, thus printing
A B C D E
A B C D
A B C
A B
A
Q.2 What is the output of this program?
#include <iostream> using namespace std; int main() { int counter = 1; do { printf ( "%d, " , counter); counter += 1; } while (counter >= 10); printf ( "\nAfter loop counter=%d" , counter); printf ( "\n" ); return 0; } |
Options
a) After loop counter=1
b) 1,
After loop counter=2
c) 1,
After loop counter=1
d) After loop counter=2
ans:- b
Explanation :- do while is an exit controlled loop, here loop body executed first, then condition will be checked.
Q.3 What is the output of this program?
#include <iostream> using namespace std; int main() { int counter = 1; while (counter >= 10) { printf ( "%d, " , counter); counter += 1; } printf ( "\nAfter loop counter=%d" , counter); printf ( "\n" ); return 0; } |
Options
a)After loop counter=1
b)1,
After loop counter=2
c)1,
After loop counter=1
d)After loop counter=2
ans:- a
Explanation :- since while is an entry controlled loop so, here condition will be checked first.
Q.4 What is the output of this program?
#include <iostream> using namespace std; int main() { int loopvar = 10; while ( printf ( "Hello " ) && loopvar--) ; return 0; } |
Options
a)Hello
b)Hello Hello Hello Hello …….
c)Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello
d)Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello Hello
ans:- d
Explanation :- since post decrement operator is used so value is decremented after expression loopvar – – is evaluated. Thus, Hello is printed 11 times.
Q.5 What is the output of this program?
#include <iostream> #include <string.h> using namespace std; int main() { int counter = 1; while (counter <= 10 && 1 ++) printf ( "Hello" ); return 0; } |
Options
a)compilation error
b)HelloHello … 10 times
c)HelloHello … 11 times
d)Hello
ans:- a
Explanation :- Error: lvalue required as increment operand. It is a compile time error.
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