• Skip to main content
  • Skip to primary sidebar
  • Skip to secondary sidebar
  • Skip to footer

Computer Notes

Library
    • Computer Fundamental
    • Computer Memory
    • DBMS Tutorial
    • Operating System
    • Computer Networking
    • C Programming
    • C++ Programming
    • Java Programming
    • C# Programming
    • SQL Tutorial
    • Management Tutorial
    • Computer Graphics
    • Compiler Design
    • Style Sheet
    • JavaScript Tutorial
    • Html Tutorial
    • Wordpress Tutorial
    • Python Tutorial
    • PHP Tutorial
    • JSP Tutorial
    • AngularJS Tutorial
    • Data Structures
    • E Commerce Tutorial
    • Visual Basic
    • Structs2 Tutorial
    • Digital Electronics
    • Internet Terms
    • Servlet Tutorial
    • Software Engineering
    • Interviews Questions
    • Basic Terms
    • Troubleshooting
Menu

Header Right

Home » C » Operator » How does the prefix and postfix operator on expression
Next →
← Prev

How does the prefix and postfix operator on expression

By Dinesh Thakur

The operators present in prefix and postfix are

  • prefix increment operator denoted by ++
  • prefix decrement operator denoted by —
  • postfix increment operator
  • postfix decrement operator

The difference between the two is that in the postfix notation, the operator appears after postfix-expression, whereas in the prefix notation, the operator appears before expression that is for example

x–;

denote postfix-decrement operator and
–x;

denote prefix decrement operator.

Having seen the difference with respect to notation now let us see the difference between both prefix and postfix with respect to functionality. The prefix increment operator adds one to its operand. This incremented value is used in the expression to get the result of the expression.

The prefix decrement operator is similar to the prefix increment operator, except that the operand is decremented by one and the decremented result is used in the expression to get the value of the expression. In other words in postfix increment or decrement operation the In the postfix form, the increment or decrement takes place after the value is used in expression evaluation.

In prefix increment or decrement operation the increment or decrement takes place before the value is used in expression evaluation. Also Precedence denotes the priority of operators. In other words if number of operators occur in a expression the priority in which eth operators gets executes is decided by precedence of operators. Associativity is the order n which a operator gets executes.

Prefix and postfix gets the highest precedence among the operators and the associativity of these is from right to left. That is the operator gets executed from right to left in an expression.

Now let us see how postfix and prefix increment and decrement operator gets evaluated as


<strong>Program 1:</strong>
main() {
  int a=5,b;
  b= ++a + 5;
  printf("a=%d b=%d",a,b);
}
<strong>Program2:</strong>
main() {
  int a=5,b;
  b= a++ + 5;
  printf("a=%d b=%d",a,b);
}


In this program1 makes use of prefix increment operator that is ++a so value of a is incremented and then used in expression which gives a=a+1 which gives value of a as 6  then b becomes b=6+5=11 so the output of prgram1 is

a = 6 b =11

In this program2 makes use of postfix increment operator that is a++ so value of a is used in expression with then incremented which gives b = 5+5=10  a=a+1 makes value of a as 6 so the output of prgram2 is

a=6 b=10

The prefix and postfix have difference only in the way they operate and have nothing to do in terms of execution speed. In other words both operate in the same speed and have no difference in this regard.

You’ll also like:

  1. Write a C++ program to Overloaded ++operator in both prefix and postfix.
  2. Ternary Operator in C
  3. Write A C++ Program To Explain The Use of Increment And Decrement Operator (Prefix).
  4. Write A C++ Program To Explain The Use of Increment And Decrement Operator (Postfix).
  5. Define Operator, Operand, and Expression in ‘C’
Next →
← Prev
Like/Subscribe us for latest updates     

About Dinesh Thakur
Dinesh ThakurDinesh Thakur holds an B.C.A, MCDBA, MCSD certifications. Dinesh authors the hugely popular Computer Notes blog. Where he writes how-to guides around Computer fundamental , computer software, Computer programming, and web apps.

Dinesh Thakur is a Freelance Writer who helps different clients from all over the globe. Dinesh has written over 500+ blogs, 30+ eBooks, and 10000+ Posts for all types of clients.


For any type of query or something that you think is missing, please feel free to Contact us.


Primary Sidebar

C Programming

C Programming Tutorials

  • C - History
  • C - Anatomy
  • C - Constants
  • C - Identifiers
  • C - Data Types
  • C - Libraries File
  • C - Header Files
  • C - Basic Language
  • C - Data Types Sizes
  • C - Header Files Importance
  • C - Escape Sequences
  • C - Main() Purpose
  • C - Program Procedure
  • C - Control Statements
  • C - Enumeration Constant
  • C - Add numbers
  • C - Return Statement
  • C - Avoid Goto
  • C - Command Line Arguments
  • C - Switch Case
  • C - Switch Case Limitations
  • C - getchar() and putchar()
  • C - Iteration Statements
  • C - Pass by Value and Reference
  • C - Structures and Unions
  • C - Structure
  • C - Dynamic Memory
  • C - Fgets and Fputs Functions
  • C - Gets() and Puts() Functions
  • C - Armstrong Number
  • C - Storage Classes
  • C - Fibonacci Series
  • C - Precision Setting
  • C - const Parameters

C - Variable & It's Type

  • C - Variables
  • C - Variable Lifetime
  • C - Static Variable
  • C - Register Variable
  • C - Global Variables
  • C - Auto Variables
  • C - Local Variables

C - Operator & Expressions

  • C - Operator
  • C - Boolean Operators
  • C - Bitwise Operator
  • C - Arithmetic Operators
  • C - Modulus Operator
  • C - Ternary Operator
  • C - Expressions
  • C - Arithmetic Expressions

C - Array

  • C - Arrays
  • C - Array Types
  • C - Array Characteristics
  • C - Static Arrays
  • C - Global Arrays
  • C - 3D Arrays
  • C - Dynamic Arrays
  • C - Pointer to 3D Arrays
  • C - Array Elements Hold
  • C - Arrays as Function Parameters
  • C - Accessing Matrix Elements
  • C - File Handling
  • C - Matrix Multiplication
  • C - Dynamic Memory Allocation

C - Searching & Sorting

  • C - Data Structures
  • C - Linear Search
  • C - Bubble Sort
  • C - Merge Sort
  • C - Linked List
  • C - Insertion Sort
  • C - Binary Search
  • C - Selection Sort
  • C - Quick Sort

C - Functions

  • C - Functions
  • C - Functions Advantages
  • C - Void Functions
  • C - Function Call
  • C - Default Return Value
  • C - String functions

C - Pointer

  • C - Pointers
  • C - Type Casting Of Pointers
  • C - Pointer Advantages
  • C - Pointers Initialization
  • C - Vectors and Pointers

C - Differences

  • C - C Vs C++
  • C - Formal Args. Vs Actual Args.
  • C - Keywords Vs Identifiers
  • C - Strings Vs Character Arrays
  • C - Address Vs Dereference Operator
  • C - Goto Vs longjmp
  • C - Declaring Vs Defining Variable
  • C - String Vs Array
  • C - Call by Value Vs Reference
  • C - Structure Vs Union
  • C - For Vs While loops
  • C - Compiler Vs Interpreter

C - Programs

  • C Program Standard Deviation
  • C Program Calculate Tax
  • C Program Sum Series
  • C Program Merge Arrays
  • C Program Euclid’s Algorithm
  • C Program Print Weekdays
  • C Program Sum of Digits
  • C Program Print a list
  • C Program Print Pythagorean
  • C Program Quiz program
  • C Program Display Table
  • C Program Print Comma-Separated
  • C Program Prints Prime Numbers
  • C Program for Print Integer
  • C Program Count Number
  • C Program Print Color Name
  • C Program Print Odd Numbers
  • C Program Calculate area
  • C Program for a Menu
  • C Program Add Two Vectors
  • C Program Array Addresses
  • C Program Division by Zero Error
  • C Program Compare two Dates
  • C Program Tower of Hanoi
  • C Program return 3 Numbers
  • C Program for Prime Numbers
  • C Program for Factorial
  • C Program for Palindrome

Other Links

  • C Programming - PDF Version

Footer

Basic Course

  • Computer Fundamental
  • Computer Networking
  • Operating System
  • Database System
  • Computer Graphics
  • Management System
  • Software Engineering
  • Digital Electronics
  • Electronic Commerce
  • Compiler Design
  • Troubleshooting

Programming

  • Java Programming
  • Structured Query (SQL)
  • C Programming
  • C++ Programming
  • Visual Basic
  • Data Structures
  • Struts 2
  • Java Servlet
  • C# Programming
  • Basic Terms
  • Interviews

World Wide Web

  • Internet
  • Java Script
  • HTML Language
  • Cascading Style Sheet
  • Java Server Pages
  • Wordpress
  • PHP
  • Python Tutorial
  • AngularJS
  • Troubleshooting

 About Us |  Contact Us |  FAQ

Dinesh Thakur is a Technology Columinist and founder of Computer Notes.

Copyright © 2025. All Rights Reserved.

APPLY FOR ONLINE JOB IN BIGGEST CRYPTO COMPANIES
APPLY NOW