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Re: Simple if-exercises

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On 4/2/2015 10:53 AM, Jeff Higgins wrote:
> On 04/02/2015 09:58 AM, Jeff Higgins wrote:
>> On 04/01/2015 08:10 PM, Stefan Ram wrote:
>>>    I was looking for very simple if-exercises.
>>>
>>>    I usually found exercises like this:
>>>
>>>        »Print "positive" if x > 0, "non-positive", otherwise.«
>>>
>>>    The expected answer would be
>>>
>>> if( x > 0 )
>>> System.out.println( "positive" );
>>> else
>>> System.out.println( "non-positive" );
>>>
>>>    However, I already have taught »?:«, so the better
>>>    (shorter) solution would be:
>>>
>>> System.out.println( ( x > 0 ? "" : "non-" )+ "positive" );
>>>
>>>    . Do you know a very simple if-exercise whose solution
>>>    cannot be written more tersely with the ternary operator
>>>    or where the formulation with »if« is clearly better than
>>>    with the ternary operator?
>>>
>>>    Knowledge that can be assumed: calls and declarations of
>>>    static methods, +, -, *, /, usage of variables, declarations
>>>    of local variables, boolean, int, double, String, literals,
>>>    the block {...}, ?:, <, >, <=, >=, !=, ==.
>>>
>> Why don't we have a Quinary operator?
>> x ? y LT : EQ : GT
>>
> Or Senary might be better - avoids an unchecked exception.
> x ? y LT : EQ : GT : NC
> 

Why not?  FORTRAN has arithmetic IF statements, where the branch is made
dependent on whether the result of the expression is less than, equal to
or greater than 0.  I found it quite useful at times when I was doing
FORTRAN II programming.

Of course, it also has a computed GOTO statement, but that's similar to
(but more restrictive than) switch/case statements.  Of course, it's
also not structured programming.

-- 
==================
Remove the "x" from my email address
Jerry Stuckle
jstucklex@attglobal.net
==================

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Re: Simple if-exercises Jeff Higgins <jeff@invalid.invalid> - 2015-04-02 09:58 -0400
  Re: Simple if-exercises Jeff Higgins <jeff@invalid.invalid> - 2015-04-02 10:53 -0400
    Re: Simple if-exercises Jerry Stuckle <jstucklex@attglobal.net> - 2015-04-02 15:08 -0400
  Re: Simple if-exercises Gene Wirchenko <genew@telus.net> - 2015-04-02 16:46 -0700
  Re: Simple if-exercises v_borchert@despammed.com (Volker Borchert) - 2015-04-03 06:29 +0000
    Re: Simple if-exercises Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-03 10:29 +0000
      Re: Simple if-exercises v_borchert@despammed.com (Volker Borchert) - 2015-04-03 18:05 +0000
        Re: Simple if-exercises Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-03 19:31 +0000
          Re: Simple if-exercises Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-04-03 16:07 -0400
            Re: Simple if-exercises Martin Gregorie <martin@address-in-sig.invalid> - 2015-04-03 21:45 +0000
          Re: Simple if-exercises v_borchert@despammed.com (Volker Borchert) - 2015-04-03 23:49 +0000
    Re: Simple if-exercises Eric Sosman <esosman@comcast-dot-net.invalid> - 2015-04-03 07:38 -0400
      Re: Simple if-exercises Jeff Higgins <jeff@invalid.invalid> - 2015-04-03 20:06 -0400

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