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Saturday, June 02, 2007

Operators in C++ Part I

C++ has a vast range of operators, in fact C++ has greater number of operators than most other programming languages.

Operators in C++ are divided into categories namely arithmetic, relational, logical, conditional, bitwise etc. according to the type of operation they perform.

Arithmetic Operators in C++

+, - ,*, /, % are all arithmetic operators. You should not be having any problems with the first four operators (they have their normal meaning), regarding the last one, it is known as the Modulus operator. It divides two operands (data, variable) and gives the remainder of the two upon division.

Increment (++) & Decrement (--) Operators

The increment operator acts on one operator to increase its value by one while the decrement operator does the opposite.

Prefix (++var) and postfix (var++) are the two types of increment/decrement operators. Both does the same arithmetic operation to the operand but the value of the variable in the expression is evaluated differently in different cases.

In case of prefix version, the operation (whether increment or decrement) is first performed on the variable and then evaluated with the updated value. While in case of postfix, the value of the variable is first evaluated (old value) and then updated as per the operation.

   //Program to illustrate prefix and postfix operators
   #include<iostream.h>
   void main(void)
   {
   int var=10;
   cout<<"prefix: "<<++var<<endl;//output is 11
   cout<<"postfix: "<<var++<<endl;//output is 11 again
   //since var is first evaluated then incremented
   cout<<"value of var: "<<var<<endl;//output is    12
   }

Relational Operators

Relational operators determine the relation among the different operands. There are six types of relational operators in C++, which are:

> (greater than) >+ (greater than or equal to) < (lesser than) <= (lesser than or equal to) == (equal to) != (not equal to)

These operators return True (1) and False (0) values in the expression.

   //Program to illustrate relational operators
   #include<iostream.h>
   void main(void)
   {
   int a=5,b=10,c=15,r;
   r=a<b;
   cout<<r;//true (1)
   r=(b==c);
   cout<<r;//false (0)
   r=(a!=b);
   cout<<r;//true (1)
   }

One thing to note here is that, = and == are different, = is an assignment operator while == is a relational operator which checks whether two operands are equal or not.

I do not think there is any need to discuss about these operators in detail (they have their usual meaning).

1 comment:

  1. Anonymous12:54 PM

    No way it is concerned with operator overloading.

    ReplyDelete

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