Selection

Selection uses if statements and switch statements. These allow your programs to make decisions or change the course of your program based on an input or a variable.

If / If Else

if statements work by performing an action only if a condition is reached. After the if command, the condition should be within round brackets, the contents of which should equate to true or false.

1 if (a > b)
2   {
3     Console.WriteLine("A is greater than B");
4   }

This can also be paired with else, which will perform an action if the "if" condition is not met.

1 if (a > b)
2   {
3     Console.WriteLine("A is greater than B");
4   }
5   else
6   {
7     Console.WriteLine("A is not Greater Than B");
8   }

Else If

 1 if (a > b)
 2   {
 3     Console.WriteLine("A is greater than B");
 4   }
 5   else if (a > c)
 6           {
 7              Console.WriteLine("A is greater than C");
 8           }
 9   else
10   {
11     Console.WriteLine("A is not Greater Than B or C");
12   }

Switch / Case

Switch is basically a combined if and if else statement, and is used for a lot of different options.

1 switch(x)
2   { 
3     case 1:
4       x++;
5       break;
6     case 2:
7       x--;
8       break;
9   }

Default is an optional part of the switch method, which is used in case none of the other conditions are met.

 1 switch(x)
 2   { 
 3     case 1:
 4       x++;
 5       break;
 6     case 2:
 7       x--;
 8       break;
 9     default:
10       x*= x;
11       break;
12   }

Nesting Statements

Both if and switch statements can be nested, meaning that one statement can be contained within another.

<syntaxhighlight lang="csharp" line> if (a > b)

 {
   if (b > 50)
     {
       Console.WriteLine("b is a very large number!");
     }
 }