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Separation 1.0 / 0.0: output infinite

double d=1.0/0.0;

output Infinity 

double d=1/0;

conclusion ArithmeticException

.

What is the difference between the two? What does Infinity mean here?

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The first case is treated as division by double, and later as division by int, and therefore an ArthimeticException.

That's what infinity means



http://docs.oracle.com/javase/7/docs/api/java/lang/Double.html#POSITIVE_INFINITY

The separation of doubles and floats follows the IEEE 754 standard for floating point matching, which should not throw an exception.

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Mathematically, division by zero is undefined, although it can be considered unconscious. (With a little more stringency, this is a number greater than x for any value of x.)

IEEE754 double floating point (used by Java) has infinity representation. This is a 1.0 / 0.0 result. In this sense, 1.0 / 0.0 is computed as it is in floating point arithmetic.



The integral type has no infinity representation, so an exception is thrown. 1 / 0

calculated in integer arithmetic.

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a floating point number has a way to encode "infinity". So infinity is a valid double variable. Integer variables do not have this option. So an exception is thrown instead.

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