Re: Dynamically assign image map values?

From	"Jukka K. Korpela" <jkorpela@cs.tut.fi>
Newsgroups	comp.lang.javascript
Subject	Re: Dynamically assign image map values?
Date	2014-10-30 19:57 +0200
Organization	A noiseless patient Spider
Message-ID	<m2tu5b$lkq$1@dont-email.me> (permalink)
References	(1 earlier) <m2q89q$c5m$1@dont-email.me> <m2qkt1$reb$1@news.albasani.net> <m2rbk4$a71$1@news.albasani.net> <m2rjvi$r6c$1@news.albasani.net> <m2tssv$d2r$1@news.albasani.net>

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2014-10-30 19:35, Tuxedo wrote:

>> var area = document.createElement("area");
>> area.setAttribute("href","bla");
>> area.setAttribute("coords","100,100,300,300");
>> area.setAttribute("shape","rect");
>
> If the area coords attributes are variables, how can they be included in
> the area.setAttribute function? Eg.:

You need to construct an expression that yields a suitable string as its 
value.

> x1 = 100; y1 = 100; x2 = 300; y2 =300;
>
> area.setAttribute("coords","+x1+","+y1+","+x2+","+y2+");
>
> But this is wrong.

Yes, because only the second argument matters here, the rest are 
discarded. You need this:

area.setAttribute("coords", x1 + "," + y1 + "," + x2 + "," + y2);

So you don’t quote the variable names, as they need to be evaluated, not 
used literally. And you quote the commas, as they are to be taken 
literally. The plus + operator performs string catenation when its 
operands (or at least one of the operands) is a string.

-- 
Yucca, http://www.cs.tut.fi/~jkorpela/

Thread

Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-29 08:47 +0100
  Re: Dynamically assign image map values? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2014-10-29 10:25 +0200
    Re: Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-29 13:00 +0100
      Re: Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-29 19:28 +0100
        Re: Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-29 21:50 +0100
          Re: Dynamically assign image map values? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2014-10-30 07:51 +0200
            Re: Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-30 09:44 +0100
          Re: Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-30 18:35 +0100
            Re: Dynamically assign image map values? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2014-10-30 19:57 +0200
              Re: Dynamically assign image map values? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-10-30 19:46 +0100
                Re: Dynamically assign image map values? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2014-10-30 20:57 +0200
                Re: Dynamically assign image map values? Thomas 'PointedEars' Lahn <PointedEars@web.de> - 2014-10-30 21:26 +0100
                Re: Dynamically assign image map values? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2014-10-30 22:58 +0200
              Re: Dynamically assign image map values? Tuxedo <tuxedo@mailinator.com> - 2014-10-30 20:52 +0100
                Re: Dynamically assign image map values? "Jukka K. Korpela" <jkorpela@cs.tut.fi> - 2014-10-30 22:23 +0200

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