C#

if (x == 0) 
{
    DoSomething();
} 
else if (x == 1) 
{
    DoSomethingElse();
} 

if (x == 0) 
{
    DoSomething();
} 
else if (x == 1) 
{
    DoSomethingElse();
} 
else 
{
    throw new InvalidOperationException();
}