Arithmetic, Relational, and Logical Operators

Operators let you work with numbers, compare values, and combine conditions. C# provides a rich set of operators to perform different operations on variables and values. Operators are grouped by their functionality and usage. Here’s a complete reference:

Arithmetic Operators

Operator	Name	Example	Result
`+`	Addition	`3 + 2`	`5`
`-`	Subtraction	`5 - 2`	`3`
`*`	Multiplication	`4 * 2`	`8`
`/`	Division	`8 / 2`	`4`
`%`	Modulus	`7 % 3`	`1`
`++`	Increment	`a++`	`a = a + 1`
`--`	Decrement	`a--`	`a = a - 1`

Assignment Operators

Operator	Example	Equivalent
`=`	`a = 5`
`+=`	`a += 2`	`a = a + 2`
`-=`	`a -= 2`	`a = a - 2`
`*=`	`a *= 2`	`a = a * 2`
`/=`	`a /= 2`	`a = a / 2`
`%=`	`a %= 2`	`a = a % 2`
`&=`	`a &= b`	`a = a & b`
`\|=`	`a \|= b`	`a = a \| b`
`^=`	`a ^= b`	`a = a ^ b`
`<<=`	`a <<= 2`	`a = a << 2`
`>>=`	`a >>= 2`	`a = a >> 2`

Comparison (Relational) Operators

Operator	Name	Example	Result
`==`	Equal to	`a == b`	`true/false`
`!=`	Not equal to	`a != b`	`true/false`
`>`	Greater than	`a > b`	`true/false`
`<`	Less than	`a < b`	`true/false`
`>=`	Greater or equal	`a >= b`	`true/false`
`<=`	Less or equal	`a <= b`	`true/false`

Logical Operators

Operator	Name	Example	Result
`&&`	AND	`a && b`	`true` if both are true
`\|\|`	OR	`a \|\| b`	`true` if either is true
`!`	NOT	`!a`	`true` if a is false

Bitwise Operators

Operator	Name	Example	Result
`&`	AND	`a & b`	Bitwise AND
`\|`	OR	`a \| b`	Bitwise OR
`^`	XOR	`a ^ b`	Bitwise XOR
`~`	NOT	`~a`	Bitwise NOT
`<<`	Left shift	`a << 2`	Shifts bits left
`>>`	Right shift	`a >> 2`	Shifts bits right

Other Operators

Operator	Name	Example	Description
`? :`	Ternary/Conditional	`a ? b : c`	If `a` is true, returns `b`, else `c`
`??`	Null-coalescing	`a ?? b`	Returns `a` if not null, else `b`
`?.`	Null-conditional	`a?.b`	Returns `b` if `a` not null, else null
`=>`	Lambda	`x => x*x`	Used for lambda expressions
`is`	Type check	`a is int`	Checks if `a` is of type int
`as`	Safe cast	`a as string`	Casts `a` to string, or null
`sizeof`	Size in bytes	`sizeof(int)`	Gets size of type (unsafe context)
`typeof`	Type info	`typeof(int)`	Gets the System.Type object
`checked`	Overflow check	`checked(a + b)`	Checks for overflow
`unchecked`	Ignore overflow	`unchecked(a+b)`	Ignores overflow
`new`	Object creation	`new MyClass()`	Instantiates a new object
`delegate`	Delegate creation	`delegate {}`	Anonymous method/delegate

Operator Precedence

Operators are evaluated in a specific order. Use parentheses to clarify complex expressions.

Examples

int a = 10, b = 3;
Console.WriteLine(a + b);  // 13
Console.WriteLine(a > b && b != 0); // true
Console.WriteLine(a << 1); // 20 (bitwise left shift)
string name = null;
Console.WriteLine(name ?? "Unknown"); // "Unknown"

💡 Try It!

Write a program that checks if someone is eligible to vote (age 18 or older):

Console.Write("Enter your age: ");
int age = int.Parse(Console.ReadLine() ?? "0");
if (age >= 18) {
  Console.WriteLine("You can vote!");
} else {
  Console.WriteLine("Sorry, you are too young.");
}

Next: Learn about type conversion and manipulation in C#.