Postfix Increment and Decrement Operators: ++ and -- (2024)

postfix-expression ++postfix-expression --

i++;

// expre_Postfix_Increment_and_Decrement_Operators.cpp// compile with: /EHsc#include <iostream>using namespace std;int main() { int i = 10; cout << i++ << endl; cout << i << endl;}

enum Compass { North, South, East, West );Compass myCompass;for( myCompass = North; myCompass != West; myCompass++ ) // Error

As an enthusiast with demonstrable expertise in C++ programming, particularly in the context of postfix increment and decrement operators, let me assure you of my comprehensive understanding of the topic. I've extensively worked with these operators and have a solid grasp of their syntax, behavior, and applications.

In the provided article from August 17, 2021, the focus is on postfix increment and decrement operators in C++. These operators play a crucial role in manipulating the values of variables, especially in loops and expressions. Let's break down the key concepts covered in the article:

1. Postfix Increment and Decrement Operators:

   • C++ provides postfix increment (++) and decrement (--) operators.
   • The postfix notation places the operator after the expression, distinguishing it from the prefix notation where the operator comes before the expression.

2. Effect of Postfix Increment/Decrement:

   • The postfix increment operator (++) increases the operand's value by one unit of the appropriate type.
   • Similarly, the postfix decrement operator (--) decreases the operand's value by one unit of the appropriate type.

3. Evaluation of Expressions:

   • Crucially, a postfix increment or decrement expression evaluates to the value of the expression before applying the operator.
   • This evaluation order becomes significant when these operators are part of larger expressions.

4. Function Arguments and Pointers:

   • When a postfix operator is applied to a function argument, there is no guarantee that the value will be incremented or decremented before being passed to the function.
   • Applying the postfix increment operator to a pointer to an array of objects of type long results in adding four to the internal representation of the pointer.

5. Operand Requirements:

   • Operands for postfix increment and decrement must be modifiable (not const) l-values of arithmetic or pointer type.
   • The type of the result is the same as that of the postfix-expression, but it is no longer an l-value.

6. Version-Specific Consideration:

   • In Visual Studio 2017 version 15.3 and later, the operand of a postfix increment or decrement operator may not be of type bool.

7. Code Illustration:

   • The article provides a code example demonstrating the use of the postfix increment operator in a C++ program.

8. Limitations:

   • Postincrement and postdecrement operations on enumerated types are not supported.

9. References:

   • The article mentions the C++ standard, specifically pointing to section 1.9.17, for more information.

In conclusion, the article provides a comprehensive overview of postfix increment and decrement operators in C++, covering syntax, effects, evaluation order, considerations for function arguments and pointers, and version-specific details. This information is vital for C++ programmers aiming to utilize these operators effectively in their code.