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Increment and Decrement Operators

                 C++ provides increment (++) and decrement  (– –) operators  which are  used to increase or
                 decrease the value of a variable by 1. These are called unary operators because they operate on
                 a single operand. For example:

                 a = 10;
                 a = ++a;   // means a = a + 1
                 a = --a;  // means a = a - 1

                 C++ allows you to use these operators in two ways:
                    Prefix (++a or --a): The operator is placed before the operand.

                    Postfix (a++ or a--): The operator is placed after the operand.
                 The difference between prefix and postfix (++ and – –) operators is that, in case of prefix operators
                 the value of the variable is incremented/decremented first and then the expression is evaluated.
                 In case of postfix operators, the expression is evaluated first and then the value of the variable is
                 incremented/decremented. Consider the preceding example:

                 int a = 10, b = 0;
                 b = ++a;       //Prefix increment: a is incremented first, then assigned to b.
                 b = a++;  // Postfix increment: a is assigned to b first, then incremented.
                 b = --a;  // Prefix decrement: a is decremented first, then assigned to
                                   b.
                 b = a--;  // Postfix decrement: a is assigned to b first, then decremented.
                 Program 6: To use prefix increment/decrement operators.

                 #include<iostream.h>                        DOSBox 0.74, Cpu speed: max 100% cycles, Frames 0, Program:
                                                          The old value of a is: 10
                 #include<conio.h>
                                                          The value of a after prefix increment is: 11
                 void main()                              The value of b is: 11
                 {                                        The value of a after prefix decrement is: 10
                                                          The value of c is: 10
                     clrscr();
                     int a = 10, b = 0, c = 0;
                     cout<< "The old value of a is: " << a << "\n";



                     // Prefix Increment
                     b = ++a;  // Value is incremented first, then assigned
                     cout<< "The value of a after prefix increment is: " << a << "\n";
                     cout<< "The value of b is: " << b << "\n";



                     // Prefix Decrement
                     c = --a;  // Value is decremented first, then assigned
                     cout<< "The value of a after prefix decrement is: " << a << "\n";
                     cout<< "The value of c is: " << c << "\n";


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                                                                                               Operators in C++
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