C# Relational Operators

<-- Arithmetic Operators Logical Operators -->

C# Relational Operators are used in relational expressions which always return bool type value. To demonstrate the examples below, we'll assume we define two int variables A=15 and B=5.

Operator	Usage	Description	Examples
==	A == B	Return true if A equals B otherwise false	bool C = A == B; //C is false because 15 does not equal to 5.
!=	A != B	Return false if A equals B otherwise true	bool C = A != B; //C is true because 15 does not equal to 5.
>	A > B	Return true if A is greater than B otherwise false	bool C = A > B; //C is true because 15 is greater than 5.
<	A < B	Return true if A is less than B otherwise false	bool C = A > B; //C is false because 15 is not less than 5.
>=	A >= B	Return true if A is no less than B otherwise false	bool C = A >= B; //C is true because 15 is no less than 5.
<=	A <= B	Return true if A is no greater than B otherwise false	bool C = A >= B; //C is false because 15 is greater than 5.

>= can be translated as "greater than or equal to" and <= can be translated as "less than or equal to".

Example 01-09-01

Select

									1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19

									20
21
22
23
24
25
26
								

									using System;

namespace TestRelationalOperators
{
    class Program
    {
        static void Main(string[] args)
        {
            int i, j;
            i = 9;              // 9 => i
            j = 8;              // 8 => j
            bool k = i == j;    // false => k
            Console.WriteLine("i={0}, j={1}, k={2}", i, j, k);
            Console.WriteLine("i != j: {0}", i != j);
            Console.WriteLine("i > j: {0}", i > j);
            Console.WriteLine("i < j: {0}", i < j);
            Console.WriteLine("i >= j: {0}", i >= j);
            Console.WriteLine("i <=j: {0}", i <= j);

            bool f = true;
            bool t = true;
            Console.WriteLine("f={0}, t={1}, f==t:{2}", i, j, f==t);
            Console.Read();
        }
    }
}

								

Output

									i=9, j=8, k=False
i != j: True
i > j: True
i < j: False
i >= j: True
i <=j: False
f=9, t=8, f==t:True
								

Line 9-11: Declare 2 int variables i, j and assign values.
Line 12: i == j returns false and is assigned to variable k.
Line 13: Output i, j, k.
Line 14: Output the result of i != j, apparently it returns true.
Line 15: Output the result of i > j, apparently it returns true.
Line 16: Output the result of i < j, apparently it returns false.
Line 17: Output the result of i >= j, apparently it returns true.
Line 18: Output the result of i <= j, apparently it returns false.
Line 20-21: Declare 2 bool variables and inialize them true value.
Line 22: Output f==t, because they are all true, true==true returns true of course.

Please be noticed, the outputs of true or false are all capitalized the first character. That's because they all changed to string and output.

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