C Operators and Expressions 01

What the output of the following code?

float x = 5*2+15/2+25%3 ;

printf("%g", x);

• 18

• 18.0

• 18.5

• Garbage value due to %g

Answer explanation

Expression 5*2+15/2+25%3 evaluates as:

5*2+15/2+25%3

* 10 + 15/2 + 25%3

/ 10 + 7 + 25%3

% 10 + 7 + 1

• + 17 + 1

• + 18

Store 18.0 into x (a float variable)

The %g format specifier removes trailing 0s after decimal point and prints 18 for x

In C programming language, which of the following type of operators have the highest precedence

• Relational operators

• Shift operators

• Logical operators

• Arithmetic operators

Answer explanation

Among the given options: Arithmetic Operators have highest priority followed by Shift Operators then Relational Operators and then Logical Operators.

What is the output of the following code:

int x=3, y=4;

int z = ++x * y++;

printf("%d %d %d", x, y, z);

• 4 3 12

• 4 4 16

• 4 5 16

• 4 5 20

Answer explanation

int x=3, y=4;

int z = ++x * y++;

Solves as

z = (increment x and use x) + (use y and then increment y)

z = 4 * 4 (alongside incrementing x to 4 and y to 5)

z = 16

Hence x y z values are printed as 4 5 16 respectively

The modulus operator (%) can be used with floating point values.

• True

• False

Answer explanation

The modulus operator can be used only with integer operands

!= is one of the ______ operators.

• Relational

• Logical

• Assignment

• Conditional

Which of the following is not a Bitwise operator?

• &

• |

• <<

• &&

Answer explanation

&& (Logical AND) is a Logical operator

What is the output of the following code segment assuming GCC compiler:

char c = 65;

printf("%d", sizeof(c));

• 1

• 2

• 4

• Undefined.

  Size varies from on compiler to compiler

Answer explanation

c is a char type variable.

char variables occupy 1 byte of memory. hence sizeof(c) will return sizeof(char) i.e. 1

There are 4 logical operators in C.

• True

• False

Answer explanation

C has only 3 logical operators:

&& Logical AND

|| Logical OR

! Logical NOT (Complement)

A relational expression yields a value of 1 or 0.

• True

• False

Answer explanation

Result 1 implies that the relational expression (condition) is true while result 0 implies that the relational expression (condition) is false.

Which of these operators can be used as both unary or binary operators. Select all that apply.

• ++

• -

• &

• *

• ^

Answer explanation

++ is only used as unary operator in prefix or postfix notation.

• - used a unary operator negates a numeric value.

• - used as binary operator subtracts two numeric values.

& as unary operator returns address of another variable.

& as binary operator returns Bitwise AND of 2 operands.

• * as unary operator dereferences value pointed by a pointer.

• * as binary operator performs multiplications of 2 numeric values.

^ is binary operator used to perform Bitwise XOR of two operands.