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& Operator (C# Reference)

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

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.

// cs_operator_ampersand.cs
using System;
class MainClass
    static void Main() 
        Console.WriteLine(true & false); // logical and
        Console.WriteLine(true & true);  // logical and
        Console.WriteLine("0x{0:x}", 0xf8 & 0x3f);  // bitwise and