Nested switch Statements

You can use a switch as part of the statement sequence of an outer switch. This is called a nested switch. Since a switch statement defines its own block, no conflicts arise - between the case constants in.the inner switch and those in the outer switch. For example, the following fragment js perfectly valid:

Here he case 1: statement in the inner switch does not conflict 'With the statement in the outer.switch, The count variable is only compared  list of cases . . at the outer level. If count is 1, then target is compared with the inner list cases. In summary, there are three important  of the switch statement to note: the switch diffracts the that can test for here as if can evaluate any type of Boolean expression. :mat is, the switch looks only for a match between the value of the expression and one  case constants No two case stats in the same switch can have identical' values. Of course a switch statement  by an outer switch cart have: constants in common    A switch statement is usually more efficient than a-set of ifs.

The last point is particularly interesting it gives insight in how the Java' compiler works, When it compiles a switch'statement, the Java compiler will inspect each of the case constants and create a that it will use (or selecting the path of expedition depending on the value of the expression. Therefore you need to  select among a large grate ,Jp of values, a switch statement will run much  than the' equivalent logic coded using sequence of i elses. The compiler can do this because it shows that the case constants-are all the same type and. simply must be compared for  equality with the a It expression. The compiler has no such knowledge of along list of if expressions.

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