Bugzilla – Full Text Bug Listing
| Summary: | Ternary with cast produces different output than else-if | ||
|---|---|---|---|
| Product: | [Eclipse Project] JDT | Reporter: | David Wright <david.wright> |
| Component: | Core | Assignee: | Srikanth Sankaran <srikanth_sankaran> |
| Status: | VERIFIED INVALID | QA Contact: | |
| Severity: | normal | ||
| Priority: | P3 | CC: | Olivier_Thomann, srikanth_sankaran |
| Version: | 3.7 | ||
| Target Milestone: | 3.7 M2 | ||
| Hardware: | PC | ||
| OS: | Windows XP | ||
| Whiteboard: | |||
I believe what you are observing is the correct behavior. See that javac also produces the same output. I'll dig up the relevant JLS section... (In reply to comment #1) I did wonder, when the output was the same in both Helios and Galileo. Twelve years of coding in Java and I still haven't got to the bottom of it! Here is the relevant text from JLS3 15.25 Conditional Operator ? : ... The type of a conditional expression is determined as follows: ... Otherwise, if the second and third operands have types that are convertible (§5.1.8) to numeric types, then there are several cases: ... Otherwise, binary numeric promotion (§5.6.2) is applied to the operand types, and the type of the conditional expression is the promoted type of the second and third operands. Note that binary numeric promotion performs unboxing conversion (§5.1.8) and value set conversion (§5.1.13). ... The chosen operand expression is then evaluated and the resulting value is converted to the type of the conditional expression as determined by the rules stated above. This conversion may include boxing (§5.1.7) or unboxing conversion. The operand expression not chosen is not evaluated for that particular evaluation of the conditional expression. Verified for 3.7M2 using I20100914-0100 |
Build Identifier: Galileo or Helios /** <p>Compiled under Helios or Galileo, ternary comes out wrong in one case or the other, depending on value of <code>createIntegers</code>. */ public final class TernaryWithCast{ private static void testWithFlag(boolean createIntegers){ System.out.println("createIntegers="+createIntegers); double d=0; Object ternary,elseIf; if(createIntegers)elseIf=new Integer((int)d); else elseIf=new Long((long)d); ternary=createIntegers?new Integer((int)d):new Long((long)d); System.out.println("Integer or Long:" + " else if="+elseIf.getClass().getSimpleName()+ " ternary="+ternary.getClass().getSimpleName()); if(createIntegers)elseIf=new Integer((int)d); else elseIf=new Short((short)d); ternary=createIntegers?new Integer((int)d):new Short((short)d); System.out.println("Integer or Short" + " else if="+elseIf.getClass().getSimpleName()+ " ternary="+ternary.getClass().getSimpleName()); } public static void main(String[]args){ boolean createIntegers; testWithFlag(createIntegers=false); testWithFlag(createIntegers=true); } } Reproducible: Always Steps to Reproduce: 1.Compile snippet under Galileo or Helios. 2.Run and observe output. 4.Optionally, convert ternary using content assist and retest.