UNIT 2 2.8 Operators

Question 1

is a symbol that tells the compiler to perform specific mathematical, relational or
logical manipulations.

Answer 1

Operator

Question 2

Three General Classes of C Operators

Answer 2

1. Arithmetic
2. Relational
3. Logical

Question 3

Arithmetic Operators:
* (asterisk)
/ (slash)
\+ (plus)
- (minus) 
- (unary minus)
% (modulus)
\++ (plus plus)
- - (minus minus) 
( ) (parenthesis)

Answer 3

*  = multiplication
/ = division
\+ = addition
- = subtraction
- = negation
% = modulus division
\++ = increment operator
- - = decrement operator
( ) = parenthesis

Question 4

Important Notes:
1. The operators +, -, * , and / all work the same way in C as they do in most computer
languages.

Answer 4

2+2 = 4 ganon

Question 5

Important Notes:

2. When / is applied to an integer or character, any remainder will be truncated.

Answer 5

Example
11/2 = 5, 
10/3 = 3, 
13/6 = 2, 
3/4 = 0, 
-34/3 = -11

Question 6

Important Notes:
3. The modulus division operator, % yields the remainder of an integer division. % cannot
be used on type float and double.

Answer 6

Example
11 % 2 = 1
5 % 3 = 2
147 % 20 = 7
6 % 3 = 0
-25 % 2 = -1

Question 7

Important Notes:
4. When an increment or decrement operator precedes its operand, C performs the
increment or decrement operation prior to using the operand’s value. If the operator
follows its operand, C uses the operand’s value before incrementing or decrementing it.

Answer 7

Example
X = 10;
Y = ++X;
X is 11; Y is 11

X = 10;
Y = X++;
X is 11; Y is 10

Question 8

is to add exactly one to the value of a variable.

Answer 8

Increment

++ increment operator
X++ post increment

Question 9

is to subtract exactly one from the value of a variable

Answer 9

Decrement
– decrement operator
++X pre increment

Question 10

Increment and Decrement Examples:

Answer 10

Example
1. X=X + 1 or X+=1 is the same with X++

2. Y=10, X=3
   Z=Y + X++

Z=Y+X; 13
X=X + 1; 4

Z=Y+ ++X
X=X + 1; 4
Z=Y + X; 14

Z=Y + X–
Z=Y + X; 13
X=X – 1; 2

Z=Y+ –X
X=X – 1; 2
Z=Y + X; 12

Question 11

It require only a single operand like unary plus and unary minus.

Answer 11

Unary Operators

Example
\+X, -Y,
- 
unary plus operator (+) 
– causes no change to the quantity which follows.

• unary minus operator (-)
  – causes the sign of the following quantity to be
  changed.

Question 12

It requires two operands

Answer 12

Binary Operators

Example
+ (addition) X + Y
* (multiplication) X – 3

Question 13

is C’s “shorthand” operation.

Answer 13

Combined Operators

Example
X = X + Y;
using shorthand can be expressed as X+ = Y;

There are combined operators for all of C’s Binary Operators.

Example
Long Hand Notation 
X=X + Y; 
X=X – Y;
X= X * Y; 
X=X/Y; 
X=X % Y; 

(Combined) Shorthand
X+ = Y;
X - = Y;
X* = Y;
X/ = Y;
X% = Y;

Question 14

refers to the relationship values can have with one another. It is used to determine
the relationship of one quantity to another.

Answer 14

Relational

Relational Operators Recognized by C

Symbols

> greater than
:a > b

<
less than
:a < b

> =
greater than or equal to
:ave >= 90

<=
less than or equal to
:ave <=90

= =
equal to
:a = = b

! =
not equal to
:a != 100

Question 15

refers to the ways the relationships can be connected together using the rules of formal
logic.

Answer 15

Logical

Logical Operators Recognized by C

&& and
|| or
! not

Note:
In C, true is any value other than 0; false is 0
1 - true
0 - false

Example:
N = 10 > 5 &amp;&amp; !(10 <9) || 3 <= 4
1 &amp;&amp; !( 0 ) || 1
1 &amp;&amp; 1 || 1
= 1

Question 16

uses question mark and colon symbols

Answer 16

Ternary Operator

Syntax:
Expression1?
expression2 :
expression3;

Wherein, expression1, expression2 and expression3 are expressions;

expression1 is evaluated,
if true then
expression2 is evaluated and become the value of the expression;
otherwise,
expression3 is evaluated and its value becomes the value of the expression.

Example
 x=10, y = 5;
x>y?
 sum= x + y: 
diff = x – y;

Question 17

is used to string together several expressions.

Answer 17

comma operator

Example
X= (Y=3, Y++, Y*2); Y=10;

Y = 3 
X= (Y= Y-5, 25/Y);

Y = 4
X=5

Y = 8

FinallyX = 8

Question 18

are combinations of operators, constants and variables.

Answer 18

Expressions

Question 19

Precedence of Operators

Answer 19

1. Arithmetic 
! 
\++
 - -
* 
/ 
%
 \+
 -

2. Relational 
< 
<= 
> 
>=
= =
 ! =

3. Logical
   &&
   | |

4. Other Operators ? :
= 
\+= 
-= 
*= 
/=