Types of Operators in C#

Stop Getting Confused! 

In C#, operators are special symbols used to perform operations on variables and values, such as addition, comparison, logical operations, and assignment.

Example:

int a = 10;
int b = 20;

int result = a + b;

Console.WriteLine(result); // 30

Here, + is an arithmetic operator.

1. Types of Operators in C#

| # | Operator Type | Operators | |---|---|---| | 1 | Arithmetic | +, -, *, /, % | | 2 | Relational / Comparison | ==, !=, >, <, >=, <= | | 3 | Logical | &&, ||, ! | | 4 | Assignment | =, +=, -=, *=, /=, %= | | 5 | Increment / Decrement | ++, -- | | 6 | Bitwise | &, \|, ^, ~ | | 7 | Shift | <<, >>, >>> | | 8 | Conditional / Ternary | ?: | | 9 | Null-Coalescing | ??, ??= | | 10 | Null-Conditional | ?., ?[] | | 11 | Type Testing / Conversion | is, as, typeof, sizeof | | 12 | Member / Element Access | ., [], () | | 13 | Object Creation | new | | 14 | Other Special Operators | nameof, await, =>, checked, unchecked |

2. Arithmetic Operators

Used to perform mathematical calculations.

int a = 10, b = 3;

Console.WriteLine(a + b); // 13
Console.WriteLine(a - b); // 7
Console.WriteLine(a * b); // 30
Console.WriteLine(a / b); // 3
Console.WriteLine(a % b); // 1

Note: Integer division (10 / 3) returns 3, not 3.33.

3. Relational / Comparison Operators

Used to compare two values. The result is true or false.

int a = 10, b = 20;

Console.WriteLine(a == b); // False
Console.WriteLine(a != b); // True
Console.WriteLine(a > b);  // False
Console.WriteLine(a < b);  // True
Console.WriteLine(a >= b); // False
Console.WriteLine(a <= b); // True

4. Logical Operators

Used to combine or reverse Boolean conditions.

int age = 25;
bool hasLicense = true;

Console.WriteLine(age >= 18 && hasLicense); // True
Console.WriteLine(age < 18 || hasLicense);  // True
Console.WriteLine(!hasLicense);             // False

• && — AND: Both conditions must be true.

• || — OR: At least one condition must be true.

• ! — NOT: Reverses the Boolean value.

5. Assignment Operators

Used to assign or update values.

int a = 10;

a += 5; // 15
a -= 3; // 12
a *= 2; // 24
a /= 4; // 6
a %= 4; // 2

For example, a += 5 is equivalent to a = a + 5 for this integer example.

6. Increment and Decrement Operators

Used to increase or decrease a value by one.

int a = 10;

Console.WriteLine(++a); // 11 (Pre-increment)
Console.WriteLine(a++); // 11 (Post-increment)
Console.WriteLine(a);   // 12

Console.WriteLine(--a); // 11 (Pre-decrement)
Console.WriteLine(a--); // 11 (Post-decrement)

Key difference:

• ++a — Increments first, then returns the value.

• a++ — Returns the original value, then increments.

7. Bitwise Operators

Used to perform operations on individual bits.

int a = 5; // Binary: 0101
int b = 3; // Binary: 0011

Console.WriteLine(a & b); // 1
Console.WriteLine(a | b); // 7
Console.WriteLine(a ^ b); // 6
Console.WriteLine(~a);    // -6

8. Shift Operators

Used to shift binary bits left or right.

int a = 8;

Console.WriteLine(a << 1); // 16
Console.WriteLine(a >> 1); // 4
Console.WriteLine(a >>> 1); // 4

>>> is the unsigned right-shift operator, available since C# 11.

9. Conditional / Ternary Operator

A shorthand alternative to a simple if-else.

Syntax:

condition ? valueIfTrue : valueIfFalse;

Example:

int age = 20;

string result = age >= 18 ? "Adult" : "Minor";

Console.WriteLine(result); // Adult

10. Null-Coalescing Operators

Used to provide default values when a variable is null.

string? name = null;

string result = name ?? "Guest";

Console.WriteLine(result); // Guest

Null-coalescing assignment (??=):

string? name = null;

name ??= "Benazir";

Console.WriteLine(name); // Benazir

11. Null-Conditional Operators

Used to safely access members when an object might be null.

string? name = null;

int? length = name?.Length;

Console.WriteLine(length); // Prints a blank line

Without ?., accessing name.Length when name is null would throw a NullReferenceException.

12. Type Testing / Conversion Operators

Used to check or convert types.

object value = "Hello";

Console.WriteLine(value is string); // True

string? text = value as string;

Console.WriteLine(text); // Hello

Console.WriteLine(typeof(int)); // System.Int32

13. Member and Element Access Operators

Used to access object members, array elements, and invoke methods.

string name = "Benazir";

Console.WriteLine(name.Length); // 7

int[] numbers = { 10, 20, 30 };

Console.WriteLine(numbers[0]); // 10

Here, ., [], and () are used for member access, indexing, and invocation.

14. Object Creation Operator

Used to create objects.

List<string> names = new List<string>();

names.Add("Benazir");
names.Add("John");

15. Other Special Operators

// nameof
Console.WriteLine(nameof(Console)); // Console

// Lambda operator
Func<int, int> square = x => x * x;

// checked
int a = checked(int.MaxValue + 0);

await is used with asynchronous operations, while checked and unchecked control overflow checking for certain numeric operations.

Important Operators for Interviews

Important interview questions: What is the difference between == and Equals()? Between && and &? Between ?? and ?.? Between ++a and a++? How does operator precedence work in C#?

These are the key operator concepts to understand for C# fundamentals and technical interviews.