> For the complete documentation index, see [llms.txt](https://dailyjournal.gitbook.io/notes/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://dailyjournal.gitbook.io/notes/languages/c-sharp/operators-and-expressions.md).
# Operators and Expressions
## Boolean Logical Operators
* Unary `!` (logical negation) operator.
* Binary `&` (logical `AND`), `|` (logical `OR`), and `^` (logical exclusive `OR`) operators. \
Those operators always evaluate both operands.
* Binary `&&` (conditional logical `AND`) and `||` (conditional logical `OR`) operators. \
Those operators evaluate the right-hand operand only if it's necessary.
{% hint style="info" %}
For operands of the **integral numeric types**, the `&`, `|`, and `^` operators perform bitwise logical operations.
{% endhint %}
### Logical negation operator !
bool passed = false;
Console.WriteLine(!passed); // output: True
Console.WriteLine(!true); // output: False
### Logical AND operator &
bool SecondOperand()
{
Console.WriteLine("Second operand is evaluated.");
return true;
}
bool a = false & SecondOperand();
Console.WriteLine(a);
// Output:
// Second operand is evaluated.
// False
bool b = true & SecondOperand();
Console.WriteLine(b);
// Output:
// Second operand is evaluated.
// True
### Logical OR operator |
bool SecondOperand()
{
Console.WriteLine("Second operand is evaluated.");
return true;
}
bool a = true | SecondOperand();
Console.WriteLine(a);
// Output:
// Second operand is evaluated.
// True
bool b = false | SecondOperand();
Console.WriteLine(b);
// Output:
// Second operand is evaluated.
// True
| x | y | x\&y | x\|y |
| :---: | :---: | :---: | :---: |
| true | true | true | true |
| true | false | false | true |
| true | null | null | true |
| false | true | false | true |
| false | false | false | false |
| false | null | false | null |
| null | true | null | true |
| null | false | false | null |
| null | null | null | null |
### Logical exclusive OR operator ^
Console.WriteLine(false ^ false); // output: False
Console.WriteLine(false ^ true); // output: True
Console.WriteLine(true ^ false); // output: True
Console.WriteLine(true ^ true); // output: False
### Conditional logical AND operator &&
```csharp
bool SecondOperand()
{
Console.WriteLine("Second operand is evaluated.");
return true;
}
bool a = false && SecondOperand();
Console.WriteLine(a);
// Output:
// False
bool b = true && SecondOperand();
Console.WriteLine(b);
// Output:
// Second operand is evaluated.
// True
```
### Conditional logical OR operator ||
```csharp
bool SecondOperand()
{
Console.WriteLine("Second operand is evaluated.");
return true;
}
bool a = true || SecondOperand();
Console.WriteLine(a);
// Output:
// True
bool b = false || SecondOperand();
Console.WriteLine(b);
// Output:
// Second operand is evaluated.
// True
```
| Operator Precedence |
| :------------------------------------: |
| `!` > `&` > `^` > `\|` > `&&` > `\|\|` |
## null-coalescing operators (?? and ??=)