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Test Json does not work

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0

I'm a beginner with Json, I follow this tutorial the example I have written is based on the tutorial, but I do not understand it does not work :

<script language="javascript">
var Jtext="{"variables":["var1","var2","var3"]}";
var Jobj=eval("(" + Jtext + ")");
var j=Jobj["variables"];
document.write(j[0]);
</script>

Any helps...

2012-04-04 20:59
by Marwen Trabelsi
NEVER USE EVAL!!.. eval is EVIL!!. - Vivek Chandra 2012-04-04 21:00
I just followed the tutorial... - Marwen Trabelsi 2012-04-04 21:00
are you getting any errors in the browser - Brian Hoover 2012-04-04 21:02
nothing at all; blank pag - Marwen Trabelsi 2012-04-04 21:03
whats wrong in eva - zod 2012-04-04 21:03
@zod 1) http://stackoverflow.com/questions/646597/eval-is-evil-so-what-should-i-use-instead

2) http://javascriptweblog.wordpress.com/2010/04/19/how-evil-is-eval - Vivek Chandra 2012-04-04 21:05

@zod The only time you want to use it when you want the entire and full power of the programming language in question (for example, if I use eval in Python, I accept that I may end up running a Djano web app on the development server). Turns out you almost never, and when you do, you know exactly and don't have to ask. For anything lesser, there are specifically tailored parsers, dead-simple interpreter, perhaps some regexes, or a different (often cleaner and simpler!) way to rewrite the code - NoName 2012-04-04 21:07

0

Remove the evil eval and the double quotes on that JSON Obj.

<script>
    var obj={"variables":["var1","var2","var3"]};
    var j=obj["variables"];
    document.write(j[0]);
</script>

What's wrong in Your example:

var Jtext="{"variables":["var1","var2","var3"]}";

This doesn't work. variables, var1, var2, ... are out of the string, like the syntax highlight shows us here. That leads to a Uncaught SyntaxError: Unexpected identifier.

2012-04-04 21:02
by binarious
What is the problem with "eval" - Marwen Trabelsi 2012-04-04 21:05
@SmartyTwiti Not only is not needed in the example is a heinous memory hog - iambriansreed 2012-04-04 21:06
works fine,but you did not respond to my question - Marwen Trabelsi 2012-04-04 21:07
@SmartyTwiti I did in my answer above - binarious 2012-04-04 21:08

0

Try:

<script type="text/javascript" language="javascript">

    var Jobj = {'variables':['var1','var2','var3']};

    var j = Jobj.variables;

    document.write(j[0]);

</script>
2012-04-04 21:05
by iambriansreed
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