The + operator can function as either a unary or a binary operator.

+ expr
expr1 + expr2

Where:

expr

An expression.

expr1

An expression.

expr2

An expression.

Remarks

Unary + operators are predefined for all numeric types. The result of a unary + operation on a numeric type is simply the value of the operand.

Binary + operators are predefined for numeric and string types. For numeric types, + computes the sum of its two operands. When one or both operands are of type string, + concatenates the string representations of the operands.

Delegate types also provide a binary + operator, which performs delegate concatenation.

User-defined types can overload the unary + and binary + operators (see operator).

Example

// cs_operator_plus.cs
using System;
class Test 
{
   public static void Main() 
   {
      Console.WriteLine(+5);        // unary plus
      Console.WriteLine(5 + 5);     // addition
      Console.WriteLine(5 + .5);    // addition
      Console.WriteLine("5" + "5"); // string concatenation
      Console.WriteLine(5.0 + "5"); // string concatenation
      // note automatic conversion from double to string
   }
}

Output

5
10
5.5
55
55

See Also

C# Operators | 7.6.1 Unary plus operator | 7.7.4 Addition operator