Difference in Increment ++ Operator as Prefix and Postfix

In any programming (Java, C Programming, PHP etc. ), increment ++ and decrement -- operator are used for increasing and decreasing the value of operand by 1 respectively.

Suppose, a=5 then,
++a;          //a becomes 6
a++;          //a becomes 7
--a;          //a becomes 6
a--;          //a becomes 5

Simple enough till now but, there is a slight but very important difference that a programmer should remember while using these operators.

++ and -- operator as prefix and postfix

If you use ++ operator as prefix like: ++var; then, the value of operand is increased by 1 then, only it is returned but, if you use ++ as postfix like: var++; then, the value of operand is returned first then, only it is increased by 1.

This is demonstrated by an example in these 4 different programming languages.

Languages
C Programming
C++ Programming
PHP
Java

C Programming Example

#include <stdio.h>
int main(){
  int var=5;
  printf("%d\n",var++);  
/* 5 is displayed then, only var is increased to 6 */   
  printf("%d",++var);    
/* Initially, var=6 then, it is increased to 7 then, only displayed */
  return 0; 
}

C++ Programming Example

#include <iostream>
using namespace std;
int main(){
   int var=5;
   cout<<var++<<"\n";     
/* 5 is displayed then, only var is increased to 6  */
   cout<<++var<<"\n";     
/* Initially, var=6 then, it is increased to 7 then, only displayed */
   return 0;
}

PHP Example

<?php 
Svar=5;                   
echo $var++."<br/>";    
echo ++$var;             
?>

Java Example

class Operator {
    public static void main(String[] args){
          int var=5;    
          System.out.println(var++);          
          System.out.println("\n"+ ++var);    
         }
    }

Output of all these program is same as below:

5
7