CsharpHow-ToBeginner · 3 min read

How to Use Comparison Operators in C# - Simple Guide

In C#, you use comparison operators like ==, !=, <, >, <=, and >= to compare values. These operators return true or false depending on whether the comparison is correct.

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Syntax

Comparison operators in C# compare two values and return a boolean result (true or false).

Here are the common operators:

== : Equal to
!= : Not equal to
< : Less than
> : Greater than
<= : Less than or equal to
>= : Greater than or equal to

csharp

bool result = (5 == 5); // true
bool notEqual = (5 != 3); // true
bool lessThan = (3 < 5); // true
bool greaterThan = (7 > 2); // true
bool lessOrEqual = (4 <= 4); // true
bool greaterOrEqual = (6 >= 7); // false

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Example

This example shows how to use comparison operators to compare two numbers and print the results.

csharp

using System;

class Program
{
    static void Main()
    {
        int a = 10;
        int b = 20;

        Console.WriteLine($"a == b: {a == b}");
        Console.WriteLine($"a != b: {a != b}");
        Console.WriteLine($"a < b: {a < b}");
        Console.WriteLine($"a > b: {a > b}");
        Console.WriteLine($"a <= b: {a <= b}");
        Console.WriteLine($"a >= b: {a >= b}");
    }
}

Output

a == b: False a != b: True a < b: True a > b: False a <= b: True a >= b: False

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Common Pitfalls

One common mistake is using = (assignment) instead of == (comparison). This causes errors or unexpected behavior.

Also, comparing floating-point numbers directly can be unreliable due to precision issues.

csharp

int x = 5;
// Wrong: assigns 10 to x instead of comparing
// if (x = 10) { Console.WriteLine("x is 10"); } // Error

// Correct:
if (x == 10) { Console.WriteLine("x is 10"); } else { Console.WriteLine("x is not 10"); }

Output

x is not 10

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Quick Reference

Operator	Meaning	Example	Result
==	Equal to	5 == 5	true
!=	Not equal to	5 != 3	true
<	Less than	3 < 5	true
>	Greater than	7 > 2	true
<=	Less than or equal to	4 <= 4	true
>=	Greater than or equal to	6 >= 7	false

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Key Takeaways

Use == to check if two values are equal and != to check if they are not equal.

Comparison operators return true or false based on the relationship between values.

Avoid using = (assignment) when you mean to compare with ==.

Be cautious comparing floating-point numbers directly due to precision limits.

Use comparison operators in conditions like if statements to control program flow.