Intro

January 13, 2018 2 minutes, 7 seconds

C# Arithmetic Operators

C# defines the following arithmetoc operators:

Arithmetic Operator Meaning
+ Addition
- Subtract
* Multiplication
/ Division
% Modulus
++ Increment
-- Decrement

+,-,* and / all work as you would expect them to. They cab be used with any built-in numeric data type.
When the / is applied to integers, any remainder gets truncated e.g 9/4 results to 2.

To obtain the remainder of the division you use the modulus operator,%. This operator can also be called remainder operator. e.g 9 % 4 results to 1. The modulus operator can be used with both floating point and integer numbers.

EXAMPLE ```c# using System;

namespace ArithmeticApp
{
    class Program
    {
        static void Main(string[] args)
        {
            Console.WriteLine("Addition : 9 + 4 = {0}", 9 + 4);
            Console.WriteLine("Substraction : 9 - 4 = {0}", 9 - 4);
            Console.WriteLine("Multiplication : 9 * 4 = {0}", 9 * 4);
            Console.WriteLine("Division : 9 / 4 = {0}", 9 / 4);
            Console.WriteLine("Modulus : 9 % 4 = {0}", 9 % 4);
            Console.Read();
        }
    }
}
RESULT
Addition : 9 + 4 = 13
Substraction : 9 - 4 = 5
Multiplication : 9 * 4 = 36
Division : 9 / 4 = 2
Modulus : 9 % 4 = 1
## [](#increment-and-decrement)Increment and Decrement

The `++` and the `--` are the _increment_ and _decrement_ operators respectively.  
The increment operator adds `1` to its operand while the decrement operator subtracts `1` from its operand.  
For instance:  
`i = i + 1` is the same as `i++`.  
And :  
`i = i - 1` is the same as `i--`.

The increment and decrement operators can either _prefix_ or _postfix_ the operand.
```c#
    i = i + 1

can be written as
PREFIX ```c# ++i;

or  
POSTFIX
```c#
x++;

Clearly if we were to run the above example, there is no difference between the two forms of increment operators.
However, when these operators are used in part of a larger expression, there is a significant difference.
When these operators precede their operand, the result of the operation is the value of the operand after the increment/decrement.
If it follows their operand, the result of the operation is the value of the operand before the increment/decrement.

EXAMPLE ```c# using System;

namespace ArithmeticApp
{
    class Program
    {
        static void Main(string[] args)
        {
            int a = 99,b =99,c = 99, d = 99;
            Console.WriteLine("POST-INCREMENT = {0}", a++);
            Console.WriteLine("PRE-INCREMENT = {0}", ++b);
            Console.WriteLine("POST-DECREMENT = {0}", c--);
            Console.WriteLine("PRE-DECREMENT = {0}", --d);
            Console.Read();
        }
    }
}
RESULT
POST-INCREMENT = 99
PRE-INCREMENT = 100
POST-DECREMENT = 99
PRE-DECREMENT = 98

So here's the deal:

*   `a++` : First the value of `a` is retrieved. Then it's incremented. However, the original value of `a` is what is returned. In this case `99`.
*   `++b` : Fisrt the value of `b` is incremented. Then it's retrieved and returned. So in this case `1` is added to `99` then the result,`100` is returned.
*   `c++` : First the value of `c` is retrieved. Then it's decremented. However, the original value of `c` is what is returned. In this case `99`.
*   `d--` : Fisrt the value of `d` is decremented. Then it's retrieved and returned. So in this case `1` is subtracted from `99` then the result,`98` is returned.

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