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jQuery getJSON -- how do I get at the data?

This is probably very simple for the experts -- but not for me (still trying to understand JSON):
I have assigned json data to a javascript variable (json1) using this code:

json1 = $.getJSON('selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON');

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Firefox shows me the json data was successfully got, in the following format:
json1

{"COLUMNS":["V","D"],"DATA":[["1",true],["0",false],["?","Uncertain"]]}

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Where I am stuck is -- how do I use the data (in javascript)?
I've tried:

alert(json1.COLUMNS[1]);
alert(json1.COLUMNS[D][1]);
alert(json1.COLUMNS[1][1]);
alert(json1.DATA[1]);
alert(json1.DATA[D][1]);
alert(json1.DATA[1][1]);
alert(json1[1]);
alert(json1[1][1]);

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all of which fail.
Clearly I am not doing things right, but I have no idea what I should be doing.

SOLUTION

Gurvinder Pal Singh

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SOLUTION

Kiran Sonawane

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leakim971

Use :

json1 = $.ajax({ "url":'selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON', "async":false, dataType: 'json' }).responseText;

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or :

$.ajaxSetup({async:false});
json1 = $.getJSON('selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON');

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The following should work :

alert(json1.COLUMNS[0]);
//alert(json1.COLUMNS[0][1]); // No
//alert(json1.COLUMNS[1][1]); // No
alert(json1.DATA[1]); // Not good
alert(json1.DATA[0][1]);
alert(json1.DATA[1][1]);
//alert(json1[1]); // No
//alert(json1[1][1]); // No

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ShanghaiD

ASKER

leakim971:

I've tried:

<script src="../js/jquery-1.7.1.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
json1 = $.ajax({ "url":'selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON', "async":false, dataType: 'json' }).responseText;
alert(json1.COLUMNS[0]);
alert(json1.DATA[0][1]);
alert(json1.DATA[1][1]);
});	
</script>

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but I get a json1.COLUMNS is undefined error in Firebug although Firebug also shows the correct JSON Response of:
{"COLUMNS":["V","D"],"DATA":[["1",true],["0",false],["?","Uncertain"]]}

What am I doing wrong?

ShanghaiD

ASKER

gurvinder372:

When I try:

<script src="../js/jquery-1.7.1.min.js"></script>
<script type="text/javascript">
$(document).ready(function() {
json1 = $.getJSON('selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON');
json1 = eval(json1);
while (x in json1)
{
alert(json[x]);
}
});	
</script>

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I get x is not defined error in Firebug although Firebug also shows the correct JSON Response of:
{"COLUMNS":["V","D"],"DATA":[["1",true],["0",false],["?","Uncertain"]]}

ShanghaiD

ASKER

sonawanekiran:

Your code works perfectly (and helps me understand how to reference the returned JSON elements). Thanks!

However, I still cannot get success with my actual cfc call, either with

json1 = $.getJSON('selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON');

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json1 = $.ajax({ "url":'selectqueries.cfc?method=getYesNoUncertain&returnformat=JSON', "async":false, dataType: 'json' }).responseText;

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and I would really like to understand what to do fix that.

ASKER CERTIFIED SOLUTION

leakim971

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ShanghaiD

ASKER

leakim971:

Success! Thank you!

leakim971

You should read this :
http://www.phpmind.com/blog/2010/07/what-is-ajax-synchronous-and-asynchronous/
http://arshadinfo.wordpress.com/2008/05/25/what-is-the-difference-between-asynchronous-ajax-and-synchronous-request/
http://newtechies.blogspot.com/2007/12/synchronous-requests-versus.html
http://www.allinterview.com/showanswers/88917.html

ShanghaiD

ASKER

Thank you all for the collective insight/feedback which enabled me to get a better understanding of JSON and how to use it.