Java Reference
In-Depth Information
• Long integer to byte integer, short integer, character, or integer
• Floating-point to byte integer, short integer, character, integer, or long integer
• Doubleprecisionfloating-pointtobyteinteger,shortinteger,character,integer,
long integer, or floating-point
where no data loss occurs. For example, when it encounters byte b = 100; , the
compilergeneratescodethatassignsinteger100tobyteintegervariable b because100
can easily fit into the 8-bit storage location assigned to this variable.
Conditional Operators
The conditional operators consist of conditional AND ( && ), conditional OR ( || ), and
conditional( ?: ).Thefirsttwooperatorsalwaysevaluatetheirleftoperand(aBoolean
(another Boolean expression). The third operator evaluates one of two operands based
upon a third Boolean operand.
Conditional AND always evaluates its left operand and evaluates its right operand
only when its left operand evaluates to true. For example, age > 64 &&
stillWorking first evaluates age > 64 . If this subexpression is true,
stillWorking is evaluated, and its true or false value ( stillWorking is a
Booleanvariable)servesasthevalueoftheoverallexpression.If age > 64 isfalse,
stillWorking is not evaluated.
whenitsleftoperandevaluatestofalse.Forexample, value < 20 || value >
40 firstevaluates value < 20 .Ifthissubexpressionisfalse, value > 40 iseval-
uated,anditstrueorfalsevalueservesastheoverallexpression'svalue.If value <
20 is true, value > 40 is not evaluated.
saryevaluationofsubexpressions,whichisknownas short-circuiting .Forexample,if
the fact that the overall expression will evaluate to false.
If you aren't careful, short-circuiting can prevent side effects (the results of subex-
example, age > 64 && ++numEmployees > 5 increments numEmployees for
only those employees whose ages are greater than 64. Incrementing numEmployees
is an example of a side effect because the value in numEmployees persists after the
subexpression ++numEmployees > 5 has evaluated.
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