BY
DINESH THAKUR
An
operator is a symbol which helps the user to command the computer to
do a certain mathematical or logical manipulations. Operators are used in C++
language program to operate on data and variables. C++ has a rich set of
operators which can be classified as
(1)
Arithmetic Operators
(2)
Relational Operators
(3)
Logical Operators
(4)
Assignment Operators
(5)
Increments and Decrement Operators
(6)
Conditional Operators
(7)
Bitwise Operators
(8)
Special Operators
(1)
Arithmetic Operators : All the basic arithmetic operations can be carried out
in C++. All the operators have almost the same meaning as in other languages.
Both unary and binary operations are available in C++ language. Unary
operations operate on a singe operand, therefore the number 5 when operated by
unary – will have the value –5.
Examples
of arithmetic operators are :
x
+ y
x
- y
-x
+ y
a
* b + c
-a
* b
etc.,
here
a, b, c, x, y are known as operands. The modulus operator is a special operator
in C++ language which evaluates the remainder of the operands after division.
Integer
Arithmetic : When an
arithmetic operation is performed on two whole numbers or integers than such an
operation is called as integer arithmetic. It always gives an integer as the
result. Let x = 27 and y = 5 be 2 integer numbers.
Then
the integer operation leads to the following results :
x
+ y = 32
x
– y = 22
x
* y = 115
x
% y = 2
x
/ y = 5
In
integer division the fractional part is truncated.
Floating
Point Arithmetic : When an
arithmetic operation is preformed on two real numbers or fraction numbers such
an operation is called floating point arithmetic. The floating point results
can be truncated according to the properties requirement. The remainder
operator is not applicable for floating point arithmetic operands.
Let
x = 14.0 and y = 4.0 then
x
+ y = 18.0
x
– y = 10.0
x
* y = 56.0
x
/ y = 3.50
Mixed
mode arithmetic : When one of the
operand is real and other is an integer and if the arithmetic operation is
carried out on these 2 operands then it is called as mixed mode arithmetic. If
any one operand is of real type then the result will always be real thus
15/10.0 = 1.5.
(2)
Relational Operators : Often it is
required to compare the relationship between operands and bring out a decision
and program accordingly. This is when the relational operator come into
picture. C++ supports the following relational operators.
It
is required to compare the marks of 2 students, salary of 2 persons, we can
ompare them using relational operators. A simple relational expression contains
only one relational operator and takes the following form :
exp1
relational operator exp2
Where
exp1 and exp2 are expressions, which may be simple constants, variables or
combination of them. Given below is a list of examples of relational
expressions and evaluated values.
6.5
<= 25 TRUE
-65
> 0 FALSE
10
< 7 + 5 TRUE
Relational
expressions are used in decision making statements of C++ language such as if,
while and for statements to decide the course of action of a running program
(3) Logical Operators : C++ has the following logical
operators, they compare or evaluate logical and relational expressions.
Logical
AND (&&) : This operator
is used to evaluate 2 conditions or expressions with relational operators
simultaneously. If both the expressions to the left and to the right of the
logical operator is true then the whole compound expression is true.
Example
:
a
> b && x = = 10
The
expression to the left is a > b and that on the right is x == 10 the whole
expression is true only if both expressions are true i.e., if a is greater than
b and x is equal to 10.
Logical
OR (||) : The logical OR
is used to combine 2 expressions or the condition evaluates to true if any one
of the 2 expressions is true.
Example
:
a
< m || a < n
The
expression evaluates to true if any one of them is true or if both of them are
true. It evaluates to true if a is less than either m or n and when a
is
less than both m and n.
Logical
NOT (!) : The logical not
operator takes single expression and evaluates to true if the expression is
false and evaluates to false if the expression is true. In other words it just
reverses the value of the expression.
For
example :
!
(x >= y)
The
NOT expression evaluates to true only if the value of x is neither greater than
or equal to y.
(4)
Assignment Operators : The Assignment
Operator evaluates an expression on the right of the expression and substitutes
it to the value or variable on the left of the expression.
Example
:
x
= a + b
Here
the value of a+b is evaluated and substituted to the variable x. In addition,
C++ has a set of shorthand assignment operators of the form.
var
oper = exp;
Here
var is a variable, exp is an expression and oper is a C++ binary arithmetic
operator. The operator oper = is known as shorthand assignment operator.
Example
:
x
+ = 1 is same as x = x + 1
The
commonly used shorthand assignment operators are as follows:
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