The default keyword is used to label the default branch in a switch statement.
int arg = <some value>;
switch (arg)
{
case 1:
<statements>
break;
case 2:
<statements>
break;
default:
<statements>
break;
}
A default block does not have an implicit ending point. A break statement is typically used at the end of each case or default block to exit the switch statement upon completion of the block.
Without a default statement, a switch statement whose argument matches no case blocks will do nothing.