Specialized C# Operators

In a previous post I went over some random C# operators. This article is a follow-up to that one, covering some more advanced C# operators and techniques. Specifically, the ?: operator, the ~ operator, |= operator, and the ^= operator.

We will start off with the conditional operator ?:. This operator is used to simplify an expression to test for a boolean value, and execute specific code that matches the value. Let’s start off with a code snippet that does not use the ?: operator.

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int TestValue = 6;
int result = -1;

if(TestValue <= 5)
    result = 0;
else
    result = 1;

Instead we can use ?: to simplify that. We can refactor that into a new code snippet:

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int TestValue = 6;

int result = TestValue <= 5 ? 0 : 1;

In plain English the ?: operator reads as:

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condition ? CodeIfTrue : CodeIfFalse;

Now we will move onto the ~ operator. This operator is used for a NOT bitwise operation, or better stated from MSDN:

The ~ operator performs a bitwise complement operation on its operand. Bitwise complement operators are predefined for int, uint, long, and ulong.

Source: ~ Operator

A NOT bitwise operation is also known as a one’s compliment operation. It takes the binary of a variable or object, and flips each bit to a 0 if it was a 1, and to a 1 if it was a 0. The code below demonstrates the operator:

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byte OriginalValue = 208;
byte complement = (byte) ~OriginalValue;

string OriginalString = Convert.ToString(OriginalValue, 2);
string ComplementString = Convert.ToString(complement, 2);

Console.WriteLine(OriginalString.PadLeft(8, '0'));
Console.WriteLine(ComplementString.PadLeft(8, '0'));

/*
Prints to screen the following:
11010000
00101111
*/

As you can see, all of the bits are flipped to their opposite partner. This is could be useful if you are using C# to interact with a piece of hardware, and need to manipulate the bits of data that is exchanged with said hardware.

Next we have the |= operator. This operator performs a bitwise OR operation against a variable. So when compare two values, if one or both are true, then the result must be true. The following C# code shows an example of the OR operation:

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byte Value1 = 245;
byte Value2 = 113;

string Value1String = Convert.ToString(Value1, 2);
string Value2String = Convert.ToString(Value2, 2);

Console.WriteLine(Value1String.PadLeft(8, '0'));
Console.WriteLine(Value2String.PadLeft(8, '0'));

Value1 |= Value2;
string ResultString = Convert.ToString(Value1, 2);
Console.WriteLine("OR:");
Console.WriteLine(ResultString.PadLeft(8, '0'));

/*
Prints to screen the following:
11110101
01110001
OR:
11110101
*/

Once again, this is useful for specific hardware signaling or situations where specific binary operations are needed.

Finally we have the ^= operator. This operator is another bitwise operator, specifically the exclusive OR (XOR). An XOR operation returns a true result if exactly one operand has a true value. If both compared values are true or both are false, XOR will yield a false result. This code snippet demonstrates how it works in C#:

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byte Value1 = 245;
byte Value2 = 113;

string Value1String = Convert.ToString(Value1, 2);
string Value2String = Convert.ToString(Value2, 2);

Console.WriteLine(Value1String.PadLeft(8, '0'));
Console.WriteLine(Value2String.PadLeft(8, '0'));

Value1 ^= Value2;
string ResultString = Convert.ToString(Value1, 2);
Console.WriteLine("XOR:");
Console.WriteLine(ResultString.PadLeft(8, '0'));

/*
Prints to screen the following:
11110101
01110001
XOR:
10000100
*/

Again, this is useful for things like hardware communication or data stream manipulation.

There are a ton more bitwise operations that C# can perform, all of which are detailed on MSDN