Arithmetic & Assignment Operators

Syntax

+  -  *  /  %   +=  -=  ++  --

Examples

int a = 10, b = 3;

Console.WriteLine(a + b);  // 13
Console.WriteLine(a - b);  // 7
Console.WriteLine(a * b);  // 30
Console.WriteLine(a / b);  // 3  (integer division truncates)
Console.WriteLine(a % b);  // 1  (remainder)

double result = 10.0 / 3;   // true division with a double
Console.WriteLine(result);  // 3.3333333333333335

int score = 10;
score += 5;   // score = score + 5  -> 15
score -= 3;   // 12
score *= 2;   // 24
score /= 4;   // 6

Console.WriteLine(score);

int x = 5;
Console.WriteLine(x++);  // prints 5, THEN increments (x is now 6)
Console.WriteLine(x);     // 6

int y = 5;
Console.WriteLine(++y);  // increments FIRST, then prints (y is now 6)
Console.WriteLine(y);     // 6

Best practices

• Watch out for integer division truncating results - divide by a double or decimal literal when you need a precise fractional result
• Use decimal rather than double for any calculation involving money, to avoid floating-point rounding errors
• Be careful mixing prefix and postfix increment operators within the same complex expression - split them into separate statements for clarity
• Use compound assignment operators (+=, -=, etc.) for conciseness when updating a variable based on itself

At a glance

Purpose

Applications on the .NET platform

File extension

.cs

Runs in

.NET runtime

Usually used with

.NET SDK and libraries

Specifications & further reading

• C# language reference

Related C# documentation