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Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()?

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On 7/6/2011 3:36 PM, markspace wrote:
> On 7/6/2011 2:58 PM, Thee Chicago Wolf [MVP] wrote:
>
>> Well, I originally used int[] x = new int[str.length]; but it gives a
>> compile error. (str.length()] does work though. Guessing because it's
>
>
> Yup, I missed that one, it's length().
>
>
>> stuff that I used. Thanks for that tip! But does the - '0' portion of
>> x[i] = str.charAt(i) - '0'; just tell it to convert to its ASCII
>> value? We dicussed this here and were like WTF is this? What exactly
>> is that portion doing? Thanks for walking me through it.
>
>
> For ASCII values, UTF (what Java uses) and ASCII are the same values.
> "char" is an integer already, there's no need to convert. str.charAt( x
> ) already returns a number, just a number encoded to mean a UTF
> character (code point?).
>
> So, you just have to map one number range to another. '0' is 48 decimal.
> E.g.:
>
> '0' - '0' = 48 - 48 = 0.
> '1' - '0' = 49 - 48 = 1.
> '2' - '0' = 50 - 48 = 2.
>
> etc. Remember Neo in The Matrix? It's all just number, really, even the
> letters.
>

Or, of course, you could use the Character.digit method. It's a bit more
flexible, allowing a one line change e.g. to do hexadecimal instead of
decimal, and providing easy internationalization.

I realize these issues will probably not arise in this context, but in
general it is better to learn to use API methods than to roll your own
that deals with a subset of the cases.

Patricia

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Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-01 12:53 -0500
  Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Jeff Higgins <jeff@invalid.invalid> - 2011-07-01 17:55 -0400
  Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? markspace <-@.> - 2011-07-01 18:19 -0700
    Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-05 10:26 -0500
      Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-05 13:39 -0400
        Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-05 13:57 -0500
          Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? markspace <-@.> - 2011-07-05 13:01 -0700
            Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-05 15:47 -0500
              Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? markspace <-@.> - 2011-07-05 14:57 -0700
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-06 13:11 -0500
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? markspace <-@.> - 2011-07-06 11:54 -0700
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-06 16:58 -0500
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? markspace <-@.> - 2011-07-06 15:36 -0700
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Patricia Shanahan <pats@acm.org> - 2011-07-06 16:53 -0700
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? markspace <-@.> - 2011-07-06 18:07 -0700
              Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-07-06 09:57 +0100
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-06 13:13 -0500
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Nigel Wade <nmw-news@ion.le.ac.uk> - 2011-07-07 09:43 +0100
              Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Lothar Kimmeringer <news200709@kimmeringer.de> - 2011-07-06 11:15 +0200
                Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-06 13:14 -0500
          Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-05 16:27 -0400
            Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Lothar Kimmeringer <news200709@kimmeringer.de> - 2011-07-06 11:22 +0200
              Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-06 07:33 -0400
  Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Eric Sosman <esosman@ieee-dot-org.invalid> - 2011-07-01 23:06 -0400
    Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Patricia Shanahan <pats@acm.org> - 2011-07-01 20:28 -0700
    Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-05 10:27 -0500
  Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? Roedy Green <see_website@mindprod.com.invalid> - 2011-07-04 08:59 -0700
    Re: Convert a String to Int: can I use toInt() instead of Integer.parseInt()? "Thee Chicago Wolf [MVP]" <.@.> - 2011-07-05 10:30 -0500

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