if / else if / else

Syntax

if (condition) {\n  // code\n} else if (condition2) {\n  // code\n} else {\n  // code\n}

Examples

int age = 20;

if (age >= 18)
{
    Console.WriteLine("You are an adult");
}
else
{
    Console.WriteLine("You are a minor");
}

int score = 75;

if (score >= 90)
{
    Console.WriteLine("Grade: A");
}
else if (score >= 80)
{
    Console.WriteLine("Grade: B");
}
else if (score >= 70)
{
    Console.WriteLine("Grade: C");
}
else
{
    Console.WriteLine("Grade: F");
}

int age = 20;
string status = age >= 18 ? "adult" : "minor";
Console.WriteLine(status);  // adult

// Equivalent to:
// if (age >= 18) { status = "adult"; } else { status = "minor"; }

Best practices

• Always use curly braces {} even for single-statement blocks - it prevents subtle bugs when code is later added to a branch
• Order else if conditions from most specific to least specific when ranges overlap, since C# checks them top to bottom
• Use the ternary operator (condition ? a : b) for simple value choices, but switch to a full if/else once the logic is more involved
• Consider a switch expression instead of a long else if chain when comparing a single variable against many discrete values

At a glance

Purpose

Applications on the .NET platform

File extension

.cs

Runs in

.NET runtime

Usually used with

.NET SDK and libraries

Specifications & further reading

• C# language reference

Related C# documentation