& Operator (C# Reference)

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

Remarks

The unary & operator returns the address of its operand (requires unsafe context).

Binary & operators are predefined for the integral types and bool. For integral types, & computes the logical bitwise AND of its operands. For bool operands, & computes the logical AND of its operands; that is, the result is true if and only if both its operands are true.

The & operator evaluates both operators regardless of the first one's value. For example:

int i = 0;
if (false & ++i == 1)
{
    // i is incremented, but the conditional 
    // expression evaluates to false, so 
    // this block does not execute.
}

User-defined types can overload the binary & operator (see operator). Operations on integral types are generally allowed on enumeration. When a binary operator is overloaded, the corresponding assignment operator, if any, is also implicitly overloaded.

Example

class BitwiseAnd
{
    static void Main()
    {
        // The following two statements perform logical ANDs.
        Console.WriteLine(true & false); 
        Console.WriteLine(true & true);  

        // The following line performs a bitwise AND of F8 (1111 1000) and 
        // 3F (0011 1111). 
        //    1111 1000 
        //    0011 1111 
        //    --------- 
        //    0011 1000 or 38
        Console.WriteLine("0x{0:x}", 0xf8 & 0x3f); 
    }
}
// Output: 
// False 
// True 
// 0x38

See Also

Reference

C# Operators

Concepts

C# Programming Guide

Other Resources

C# Reference