C# If...Else

C# If...Else Statements

Conditional statements allow you to write code that only executes when specific conditions are met. This is how programs make "decisions."

C# uses the following conditional statements:

• if to specify a block of code to be executed if a condition is true.
• else to specify a block of code to be executed if the same condition is false.
• else if to specify a new condition to test, if the first condition is false.

1. The if Statement

Use the if statement to specify a block of C# code to be executed if a condition evaluates to true.

if (20 > 18) {
  Console.WriteLine("20 is greater than 18"); // This will run
}

2. The else Statement

Use the else statement to catch anything that was false in the if statement.

int time = 20;
if (time < 18) {
  Console.WriteLine("Good day.");
} else {
  Console.WriteLine("Good evening."); // This will run
}

3. The else if Statement

If you have multiple conditions, use else if to chain them together.

using System;

class Program {
  static void Main() {
    int time = 22;
    if (time < 10) {
      Console.WriteLine("Good morning.");
    } else if (time < 20) {
      Console.WriteLine("Good day.");
    } else {
      Console.WriteLine("Good evening.");
    }
  }
}

Short Hand If...Else (Ternary Operator)

There is a shorthand version of if...else, which is known as the ternary operator because it consists of three operands. It is used to replace simple if...else statements with a single line of code!

Syntax: variable = (condition) ? expressionTrue : expressionFalse;