# C# Tutorial – Arithmetic operators

Sooner or later every programmer will have to do some operations – arithmetic, logical, etc. C# has a lot of operators to help with that. And this time I’d like to introduce arithmetic operators.

### Basic arithmetic operators

The basic one are know to everyone from math lessons.

``````            int a = 4;
int b = 2;
int result = a + b; // 6
result = a - b; // 2
result = a * b; // 8
result = a / b; // 2``````

But the result of an operation isn’t as straight forward every time.

``````            int a = 5;
int b = 3;
int result = a / b; // ?``````

As you know the int  variable contains only integer values – no information about the fractional part. Can you guess the value of the result variable? Will it be rounded to 2 or will it be cut to 1? The result will be 1 – it’s because the fractional part is just lost, there is no rounding in integer arithmetic.

### Reminder operator

There is one more arithmetic operator – remainder.

``````            int a = 5;
int b = 3;
int result = a % b; // 2``````

In integer arithmetic, the a % b  get the value of a – (a / b) * b . You have to remember that in integer arithmetic a / b * b  is not always equal to a .

``````a = 5
b = 3
a % b = a - (a / b) * b = 5 - (5 / 3) * 3 = 5- 1 * 3 = 5 – 3 = 2``````

### Increment and decrement operators

There are operators that can increment or decrement a variable.

``````            int a = 5;
a++;
// a = 6

int b = 3;
b--;
// b = 2``````

Another way to do it:

``````            int a = 5;
++a;
// a = 6

int b = 3;
--b;
// b = 2``````

You might wonder what’s the difference between a++  and ++a ? In above cases they do exactly the same, but let’s look at this case:

``````            int a = 5;
int b = a++; // b = 5

a = 5;
int c = ++a; // c = 6``````

Let’s analyze it. The first case:

``````            int a = 5;
int b = a++;
// First value of variable a (5) is returned to the expression, so b = 5
// Next variable a is incremented, a = a + 1 = 6``````

The second case:

``````            int a = 5;
int b = ++a;
// First variable a is incremented, so a = a + 1 = 6
// Next value of variable a (6) is returned to the expression, b = 6``````

It works the same with decrement operator.

``````            int a = 5;
int b = a--; // b = 5

a = 5;
int c = --a; // c = 4``````

Hope it’s clear.

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## 2 thoughts on “C# Tutorial – Arithmetic operators”

• quest bars

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Thanks!