10 things you may not have known before

1. PUBLIC
Toshko Todorov, SAP
January 27, 2018
10 Things You Didn’t Know About Java
maybe

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About
 Me, Java and so on
10 Things You Didn’t Know About Java
 Slides and examples
Question and Answers
 Debate
Agenda

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Speaker
 Bachelor Degree in Mathematics and Informatics, Sofia University
“St. Kliment Ohridski”
 Senior Developer, SAP Labs Bulgaria
 5 years of development experience, generally in Java
 Interests Java EE, CI&CD, IoT
About

4. Time for presentation

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1. There is no such thing as a checked exception
The example shows how a checked exception is thrown as a runtime exception.

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2. You can have method overloads differing only in return types
The example does not compile because JVM forbids “override-equivalent” with the same class.
The example is pretty much the same. The synthetic bridge method is actually generated by the
compiler because the return type of the Parent.x() signature may be expected to Object at certain
call sites.

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3. All of these are two-dimensional arrays
Using JSR-308 / Java 8 type annotations on the above there are even more possibilities:

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4. You don’t get the conditional expression
The program above prints out:
1.0
1

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5. You also don’t get the compound assignment operator
“A compound assignment expression of the form E1 op= E2 is equivalent to E1 = (T)((E1) op
(E2)), where T is the type of E1, except that E1 is evaluated only once.”

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6. Random integers
A possible output of the program
could be:

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7. GOTO still exists but only as a keyword

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8. Java has type aliases

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9. Some type relationships are undecidable
Now, what do the types C and D even mean?

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10. Type intersections

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Questions and answers?!

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Contact information:
Toshko Todorov
Senior Developer
SAP Labs Bulgaria
Email: Toshko.Todorov@sap.com
Thank you!