Groups > comp.lang.java.programmer > #34453

Re: double-to-int conversion without a cast

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From	Eric Sosman <esosman@comcast-dot-net.invalid>
Newsgroups	comp.lang.java.programmer
Subject	Re: double-to-int conversion without a cast
Date	Fri, 3 Jun 2016 08:22:53 -0400
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On 6/3/2016 6:53 AM, Martin Gregorie wrote:
> On Thu, 02 Jun 2016 22:18:13 -0700, Roedy Green wrote:
>
>> On 25 Feb 2016 01:07:44 GMT, ram@zedat.fu-berlin.de (Stefan Ram)
>> wrote:
>>
>>> ouble to int
>>>  with only the above means
>>
>> I asked the conversion amanusensis at
>> http://mindprod.com/applet/converter.html
>>
>> it offered:
>>
>> // to int i from double d // best i = (int)d;
>> // or i = (int)Math.round(d);
>> // or i = (int)Math.ceil(d);
>> // or i = (int)Math.floor(d);
>
> This works:
>
>  int  n = new Long(Math.round(d)).intValue();
>
> Look Ma, no casts!

     Too expensive -- just *look* at that wasteful creation of an object!
Tut, tut, tut!  Try this:

       int n = Integer.parseInt(
             Double.toString(d)
                .substring(0, Double.toString(d).indexOf('.')))
             + (Double.toString(d).indexOf('.') >= 0
                && Double.toString(d).indexOf('.') + 1
                    < Double.toString(d).length()
                && Double.toString(d).charAt(
                   Double.toString(d).indexOf('.') + 1) >= '5'
             ? Double.toString(d).startsWith("-") ? -1 : 1 : 0);

     Look, Ma, no `new'!

-- 
esosman@comcast-dot-net.invalid
"Don't be afraid of work. Make work afraid of you." -- TLM

Thread

Re: double-to-int conversion without a cast Roedy Green <inquiry@mindprod.com> - 2016-06-02 22:18 -0700
  Re: double-to-int conversion without a cast Martin Gregorie <martin@address-in-sig.invalid> - 2016-06-03 10:53 +0000
    Re: double-to-int conversion without a cast Eric Sosman <esosman@comcast-dot-net.invalid> - 2016-06-03 08:22 -0400
      Re: double-to-int conversion without a cast bursejan@gmail.com - 2016-06-05 16:57 -0700

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