EXPRESSIONS

Evaluate Operands before Operation

15.6.2

class Test {

public static void main(String[] args) {

int j = 1;

try {

int i = forgetIt() / (j = 2);

} catch (Exception e) {

System.out.println(e);

System.out.println("Now j = " + j);

}

}

static int forgetIt() throws Exception {

throw new Exception("I'm outta here!");

}

}

prints:

java.lang.Exception: I m outta here!

Now j = 1

because the left hand operand

forgetIt()

 of the operator

/

 throws an exception

before the right hand operand and its embedded assignment of

2

 to

j

 occurs.

15.6.2   Evaluate Operands before Operation

Java also guarantees that every operand of an operator (except the conditional

operators

&&

,

||

, and

? :

) appears to be fully evaluated before any part of the

operation itself is performed.

If the binary operator is an integer division

/

 ( 15.16.2) or integer remainder

%

 ( 15.16.3), then its execution may raise an

ArithmeticException

, but this

exception is thrown only after both operands of the binary operator have been

evaluated and only if these evaluations completed normally.

So, for example, the program:

class Test {

public static void main(String[] args) {

int divisor = 0;

try {

int i = 1 / (divisor * loseBig());

} catch (Exception e) {

System.out.println(e);

}

}

307