Question 1

What will be the output of the program?

#include<stdio.h>
int main()
{
    int i=0;
    for(; i<=5; i++);
        printf("%d", i);
    return 0;
}

Answer

Answer: D

Step 1: int i = 0; here variable i is an integer type and initialized to '0'.
Step 2: for(; i<=5; i++); variable i=0 is already assigned in previous step. The semi-colon at the end of this for loop tells, "there is no more statement is inside the loop".

Loop 1: here i=0, the condition in for(; 0<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 2: here i=1, the condition in for(; 1<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 3: here i=2, the condition in for(; 2<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 4: here i=3, the condition in for(; 3<=5; i++) loop satisfies and then i is increemented by '1'(one)
Loop 5: here i=4, the condition in for(; 4<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 6: here i=5, the condition in for(; 5<=5; i++) loop satisfies and then i is incremented by '1'(one)
Loop 7: here i=6, the condition in for(; 6<=5; i++) loop fails and then i is not incremented.

Step 3: printf("%d", i); here the value of i is 6. Hence the output is '6'.

Question 2

Which of the following cannot be checked in a switch-case statement?

Answer

Answer: C

The switch/case statement in the c language is defined by the language specification to use an int value, so you can not use a float value.


switch( expression )
{
    case constant-expression1:    statements 1;
    case constant-expression2:    statements 2;    
    case constant-expression3:    statements3 ;
    ...
    ...
    default : statements 4;
}

The value of the 'expression' in a switch-case statement must be an integer, char, short, long. Float and double are not allowed.

Question 3

In mathematics and computer programming, which is the correct order of mathematical operators ?

Answer

Answer: B

Simply called as BODMAS (Brackets, Order, Division, Multiplication, Addition and Subtraction).

Mnemonics are often used to help students remember the rules, but the rules taught by the use of acronyms can be misleading. In the United States the acronym PEMDAS is common. It stands for Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. In other English speaking countries, Parentheses may be called Brackets, or symbols of inclusion and Exponentiation may be called either Indices, Powers or Orders, and since multiplication and division are of equal precedence, M and D are often interchanged, leading to such acronyms as BEDMAS, BIDMAS, BODMAS, BERDMAS, PERDMAS, and BPODMAS.

For more info: http://en.wikipedia.org/wiki/Order_of_operations

Question 4

Which of the following is not logical operator?

Answer

Answer: A

Bitwise operators:
& is a Bitwise AND operator.

Logical operators:
&& is a Logical AND operator.
|| is a Logical OR operator.
! is a NOT operator.

So, '&' is not a Logical operator.

Question 5

How many times the while loop will get executed if a short int is 2 byte wide?

#include<stdio.h>
int main()
{
    int j=1;
    while(j <= 255)
    {
        printf("%c %d\n", j, j);
        j++;
    }
    return 0;
}

Answer

Answer: B

The while(j <= 255) loop will get executed 255 times. The size short int(2 byte wide) does not affect the while() loop.

Questions for: Control Instructions