C# multiple choice questions on do while loop statements in C# Programming Language.
1. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int i = 1, j = 2, k = 3;
-
do -
{ -
Console.WriteLine((Convert.ToBoolean(Convert.ToInt32(i++)))
-
&& (Convert.ToBoolean(Convert.ToInt32(++j))));
-
}while (i <= 3);
-
Console.ReadLine();
-
}
a) 0 0 0
b) True True True
c) 1 1 1
d) False False False
Answer: b
Clarification: 1 AND 1 = True. Similarly, non zero number || non zero number = True.
Output:
2. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
float i = 1.0f, j = 0.05f;
-
do -
{ -
Console.WriteLine(i++ - ++j);
-
}while (i < 2.0f && j <= 2.0f);
-
Console.ReadLine();
-
}
a) 0.05
b) -0.05
c) 0.95
d) -0.04999995
Answer: d
Clarification: None.
Output :
3. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int i = 1, j = 5;
-
do -
{ -
Console.WriteLine(i = i++ * j);
-
}while (i <= 10);
-
Console.ReadLine();
-
}
a) 5 10 15 20 25 30 35 40 45 50
b) 5 25
c) 5 11 16 21 26 31 36 41 46 51
d) 5 30
Answer: b
Clarification: For first step of loop i = 1 .So, i++ * j = 1 * 5 = 5. For second step of loop i = 5, j = 5. So, i++ * j = 25. As, i = 25 hence, 25 >=10 loop condition breaks.
Output:
4. For the incomplete C# program below, which of the C# code fragment will not result in an infinite loop?
-
static void Main(string[] args)
-
{ -
int i = 1234 ,j = 0;
-
/*ADD CODE HERE */ -
Console.WriteLine(j);
-
}
a)
do { j = j + (i % 10); }while ((i = i / 10)!= 0);
b)
do { j = j + (i % 10); }while ((i / 10)!= 0);
c)
do { j = j + (i % 10); }while ((i % 10)!= 0);
d)
do { j = j + (i % 10); }while ((i/10 == 0)!= 0);
View Answer
Answer: a
Clarification: None.
Output :
static void Main(string[] args) { int i = 1234,j = 0; do { j = j +( i % 10); }while ((i = i / 10)!= 0); Console.WriteLine(j);
}
5. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
long x;
-
x = Convert.ToInt32(Console.ReadLine());
-
do -
{ -
Console.WriteLine(x % 10);
-
}while ((x = x / 10) != 0);
-
Console.ReadLine();
-
} -
enter x = 1234.
a) number of digits present in x
b) prints ‘1’
c) prints reverse of x
d) prints sum of digits of ‘x’
Answer: c
Clarification: Reverse of digits using while loop statements.
Output:
6. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int i, s = 0, a = 1, d;
-
i = Convert.ToInt32(Console.ReadLine());
-
do -
{ -
d = i % (2 * 4);
-
s = s + d * a;
-
}while ((Convert.ToInt32(i = i / (2 * 4))) != 0
-
&& (Convert.ToBoolean(Convert.ToInt32((a) = (a * 10)))));
-
Console.WriteLine(s);
-
Console.ReadLine();
-
} -
enter i = 342.
a) It finds binary equivalent of i
b) It finds octal equivalent of i
c) It finds sum of digits of i
d) It finds reverse of i
Answer: b
Clarification: None.
Output :
7. What is the correct syntax for do while loop?
a)
do; { statement; }while (condition);
b)
do(condition) { statement; }while;
c)
do { statement; }while (condition)
d)
do { statement; }while (condition);
View Answer
Answer: d
Clarification: By definition
Output:
do { statement; }while (condition);
8. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int x = 10;
-
do -
{ -
Console.WriteLine( x++);
-
} -
while(Convert.ToBoolean(5) && Convert.ToBoolean(4) && Convert.ToBoolean(3)
-
&& Convert.ToBoolean(2) && Convert.ToBoolean(1) && Convert.ToBoolean(0));
-
Console.ReadLine();
-
}
a) 13
b) 15
c) 11
d) 10
Answer: d
9. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int x;
-
for (x = 10; x <= 15; x++)
-
while (Convert.ToBoolean(Convert.ToInt32(x)))
-
{ -
do -
{ -
Console.WriteLine(1);
-
if (Convert.ToBoolean(x >> 1))
-
continue;
-
}while (Convert.ToBoolean(0));
-
break;
-
} -
Console.ReadLine();
-
}
a) 0 0 0….infinite times
b) 1 1 1….infinite times
c) 1 1 1 1 1 1
d) System outofflow exception error
10. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int x = 0;
-
do -
{ -
x++; -
if (x == 5)
-
{ -
x++; -
continue;
-
break;
-
} -
Console.WriteLine(x + " ");
-
} -
}while (x < 10);
a) 1 2 3 4 5
b) 10
c) 5 6 7 8 9 10
d) 1 2 3 4 5 6 7 8 9 10
Answer: d
11. What will be the output of the following C# code?
-
static void Main(string[] args)
-
{ -
int x;
-
for (x = 1; x <= 3; x++)
-
{ -
int j = 1;
-
do -
{ -
j++; -
}while (x % j == 2);
-
Console.WriteLine(x + " " + j);
-
} -
Console.ReadLine();
-
}
a) 1 12 1 3 1
b) 1 12 13 1
c) 12 22 32
d) 11 21 31
Answer: c
