Operators in C#

In C# programming language, an operator is an element that takes one or more operands to perform some computation. Basically, there are three kinds of operators are there in C#.

On the basis of "number of operands", the operators are classified into the following categories.

1. Unary operators : Operators that take one operand are called Unary operators (++, --, etc.)
2. Binary operators : The operators that take two operands are called Binary operators (+, -, =, /, ==, etc.).
3. Ternary operators : The operators that take three operands are called Ternary operators. There is only one such operator in C# which is the conditional operator (?:).

To understand them in an easy way, we categorize the the operators on the basis of "type of operations" that these operators perform. Let's explore each in detail.

These operators perform the arithmetic computation over the operand(s).

Run this code

using System;

class Program
{
	static void Main(string[] args)
	{
	
		Console.WriteLine("Arithmetic Operators");
		Console.WriteLine("");
		
		int x = 25;
		int y = 10;
		
		Console.WriteLine("");
		Console.Write("x = " + x);
		Console.WriteLine(" and y = " + y);
		Console.WriteLine("");
		
		Console.WriteLine("Add");
		Console.Write("x + y = ");
		Console.WriteLine(x + y);
		Console.WriteLine("");
		
		Console.WriteLine("Subtract");
		Console.Write("x - y = ");
		Console.WriteLine(x - y);
		Console.WriteLine("");
		
		Console.WriteLine("Multiply");
		Console.Write("x * y = ");
		Console.WriteLine(x * y);
		Console.WriteLine("");
		
		Console.WriteLine("Divide");
		Console.Write("x / y = ");
		Console.WriteLine(x / y);
		Console.WriteLine("");
		
		Console.WriteLine("Modulus");
		Console.Write("x % y = ");
		Console.WriteLine(x % y);
		Console.WriteLine("");
		
		Console.WriteLine("Increment");
		Console.WriteLine("");
		
		Console.WriteLine("Pre increment");
		Console.WriteLine("Before pre-increment x = " + x);
		Console.Write("During pre-increment : ++x = ");
		Console.WriteLine(++x);
		Console.WriteLine("After pre-increment x = " + x);
		Console.WriteLine("");
		
		Console.WriteLine("Post increment");
		Console.WriteLine("Before post-increment x = " + x);
		Console.Write("During post increment : x++ = ");
		Console.WriteLine(x++);
		Console.WriteLine("After post-increment x = " + x);
		Console.WriteLine("");
		
		Console.WriteLine("Decrement");
		Console.WriteLine("Before pre-decrement x = " + x);
		Console.Write("During pre-decrement : --x = ");
		Console.WriteLine(--x);
		Console.WriteLine("After pre-decrement x = " + x);
		Console.WriteLine("");
		
		Console.WriteLine("Post decrement");
		Console.WriteLine("Before post-decrement x = " + x);
		Console.Write("During post-decrement : x-- = ");
		Console.WriteLine(x--);
		Console.WriteLine("After post-decrement x = " + x);
		Console.WriteLine("");
		
		Console.Write("Press any key to continue...");
		Console.ReadKey(true);
	}
}
		

Relational Operators evaluate the comparison between the operands. C# supports the following relational operators.

Run this code

 using System;

class Program
{
	static void Main(string[] args)
	{
		Console.WriteLine("Relational Operators");
		Console.WriteLine("");
		
		int x = 25;
		int y = 10;
		
		Console.Write("Is x equals to y?");
		Console.WriteLine(x == y);
		
		Console.Write("Is x less than y?");
		Console.WriteLine(x < y);
		
		Console.Write("Is x less than or equals to y?");
		Console.WriteLine(x <= y);
		
		Console.Write("Is x greater than y?");
		Console.WriteLine(x > y);
		
		Console.Write("Is x greater than or equals to y?");
		Console.WriteLine(x >= y);
		
		Console.Write("Is x not equal to y?");
		Console.WriteLine(x != y);
	}
}
		

Logical operators evaluate the logical operations between two boolean operands. The key thing to note here is "boolean operands". This means that the operands must be a boolean type or boolean expression.

Run this code

using System;

class Program
{
	static void Main(string[] args)
	{
		Console.WriteLine("Logical Operators");
		Console.WriteLine("");
		
		bool a = true;
		bool b = false;
		
		Console.Write("a = ");
		Console.Write(a);
		Console.Write(", b = ");
		Console.WriteLine(b);
		Console.WriteLine("");
		
		Console.Write("a && b = ");
		Console.WriteLine(a && b);
		Console.WriteLine("");
		
		Console.Write("a || b = ");
		Console.WriteLine(a || b);
		Console.WriteLine("");
		
		Console.Write("!a = ");
		Console.WriteLine(!a);
		Console.WriteLine("");
	}
}
		

These operators evaluates the bitwise operation between two numeric operands.

Consider the below example.

Run this code

using System;

class Program
{
	static void Main(string[] args)
	{
		Console.WriteLine("Bitwise Operators");
		Console.WriteLine("");
		
		int a = 1; // binary equivalent is 1
		int b = 2; // binary equivalent is 10
		
		Console.Write("a = ");
		Console.Write(a);
		Console.Write(", b = ");
		Console.WriteLine(b);
		Console.WriteLine("");
		
		Console.Write("Bitwise AND : a & b = ");
		Console.WriteLine(a & b);
		Console.WriteLine("");
		
		Console.Write("Bitwise OR : a | b = ");
		Console.WriteLine(a | b);
		Console.WriteLine("");
		
		Console.Write("Bitwise XOR : a ^ b = ");
		Console.WriteLine(a ^ b);
		Console.WriteLine("");
		
		Console.Write("One's complement : ~a = ");
		Console.WriteLine(~a);
		Console.WriteLine("");
	}
}
	

Let's understand the above example. In this example, we have taken a = 1 and b = 2 are integers in decimal number system.

a's binary equivalent is 01 and b's binary equivalent is 10.

Now ANDing their bits from right to left will yield 00 as result.

	[a]			01
	[b]			10
	[ANDing]	--
				00
	

Similarly, a | b will be evaluated as 01 | 10. Now ORing their bits from right to let will yield 11. The equivalent of 11 in decimal number system is 3 which would be shown as result.

	[a]			01
	[b]			10
	[ORing]		-- 
				11
	

In the same way, the ^ operation will be performed.

The one's complement will invert all bits and yield the result. Since this negates the bits, so the number is represented in negative. Since this is signed binary integer, hence the system evaluates two's complement which is one's complement plus 1. Hence, one's complement for 1 is 0 and adding 1 to the most significant place will make it 10 which is 2 in decimal number system and with sign it will yield -2 as result.

These operator manipulates the bits of binary number or binary equivalent of a number and shifts either left or right.

Consider the below example

Run this code

using System;

class Program
{
	static void Main(string[] args)
	{
		Console.WriteLine("Shift Operators");
		Console.WriteLine("");
		
		int a = 1; // binary equivalent is 1
		int b = 2; // binary equivalent is 10
		
		Console.Write("a = ");
		Console.Write(a);
		Console.Write(", b = ");
		Console.WriteLine(b);
		Console.WriteLine("");
		
		Console.Write("Right shift : a >> b = ");
		Console.WriteLine(a >> b);
		Console.WriteLine("");
		
		Console.Write("Left shift : a << b = ");
		Console.WriteLine(a << b);
		Console.WriteLine("");
	}
}
		

The right shift operator >> shift the bits to the right. So, a >> b will shift the bits of 1 to 2 places to the right. Consider 1 as 001. Shifting one bit to the right will give 00 and shifting one more time to the right will give 0 as result which is 0 in decimal number system. The left shift a << b will shift the bits of 1 to 2 place to the left. Consider 1 as 001. Shifting one bit to right will give 010 and shifting one more time to the right will give 100 as result which is 4 in decimal number system.

	[a]									00|01|00
	[shift 2 places to right]			00|00|01		
	[result]							0000
	
	[a]									00|01|00
	[shift 2 places to left]			01|00|00		
	[result]							0100
	
* We always consider most significant digits
	

The conditional operator :? is the only ternary operator in C#. It is used to skip the simple if else block of statement (if-else statement will be covered later in this course).

It takes 3 operand and the format is - operand1 ? operand2 : operand3;

The operand1 must be a boolean operand or boolean expression. If the operand1 is true then it will return the operand2 otherwise it will return operand3 as result.

Run this code

using System;

class Program
{
	static void Main(string[] args)
	{
		Console.WriteLine("Conditional Operator");
		Console.WriteLine("");
		
		int a = 1;
		int b = 2;
		
		string c = a <= b ? "a is less than or equals to b" : "a is greater than b";
		
		Console.WriteLine(c);
	}
}