C# – if else Statement

In C#, as we know that if-statement is executed if the condition is true otherwise it will not execute. But, what if we want to print/execute something if the condition is false. Here comes the else statement. Else statement is used with if statement to execute some block of code if the given condition is false. Or in other words, in the if-else statement, if the given condition evaluates to true, then the if condition executes, or if the given condition evaluates to false, then the else condition will execute. 

• Else-statement can contain single or multiple statements in the curly braces{}. If the else statement only contains a single statement, then the curly braces are optional.
• The statements of else-statement can be of any kind/type like it may contain another if-else statement.

Syntax:

if(condition)
{  
    // code if condition is true  
}
else
{  
    // code if condition is false  
}  

Flow chart:

Example 1:

C#

// C# program to demonstrate
// if-else statement
using System;

class GFG{

static public void Main()
{

    // Declaring and initializing variables
    string x = "Geeks";
    string y = "GeeksforGeeks";

    // If-else statement
    if (x == y)
    {
        Console.WriteLine("Both strings are equal..!!");
    }

    // else statement
   else
    {
         Console.WriteLine("Both strings are not equal..!!");
    }
}
}

Output:

Both strings are not equal..!!

Example 2:

C#

// C# program to demonstrate if-else statement
using System;

class GFG{

static public void Main()
{

    // Declaring and initializing variables
    int x = 10;
    int y = 100;

    // If-else statement
    if (x >= y)
    {
        Console.WriteLine("x is greater than y");
    }

    // else statement
   else
    {
         Console.WriteLine("x is not greater than y");
    }
}
}

Output:

x is not greater than y

Short-Hand of if-else Statement

C# also provides a short-hand implementation of the if-else statement which is also known as Ternary Operator(?:) because it contains three operands. It is basically used to replace multiples lines of codes with a single line. And it will return one of two values depending on the value of a Boolean expression.

Syntax:

variable_name = (condition) ? TrueExpression :  FalseExpression;

Here, if the given condition is true, then the TrueExpression statement will execute. Or if the given condition is false, then the FalseExpression statement will execute. 

Note: C# also supports nested Ternary Operator.

Example 1: 

C#

// C# program to demonstrate short-hand
// of if-else statement
using System;

class GFG{

static public void Main()
{

    // Declaring and initializing variables
    string x = "Geeks";
    string y = "GeeksforGeeks";

    // Short-hand if-else statement
    string result = (x == y) ? "Both strings are equal" : "Not equal";

    // Display result
    Console.WriteLine(result);
}
}

Output:

Not equal

Example 2:

C#

// C# program to demonstrate nested
// Ternary Operator
using System;

class GFG{

static void Main(string[] args)
{

  int a = 23, b = 90;

  string result = a > b ? "a is greater than b" :
                  a < b ? "a is less than b" :
                  a == b ? "a is equal to b" : "Invalid";

  Console.WriteLine(result);
}
}

Output:

a is less than b