Every expression has a normal mode of evaluation in which certain computational steps are carried out. The following sections describe the normal mode of evaluation for each kind of expression.
If all the steps are carried out without an exception being thrown, the expression is said to complete normally.
If, however, evaluation of an expression throws an exception, then the expression is said to complete abruptly. An abrupt completion always has an associated reason, which is always a
throw with a given value.
Run-time exceptions are thrown by the predefined operators as follows: