Looping JSON data

Dear Experts,

I have the following javascript which does not work properly

objJSON = eval('('+ results +')');

for(var i = 0, e = objJSON.selectbox1.length; i < e; ++i) {
    var option = new Option(objJSON.selectbox1[i].value, objJSON.selectbox1[i].text);
    document.getElementById('selItemType').options[i] = option;
}

It should be populating my html select control, but it just fills it up with "undefined" values.

The json data looks like this

{
"textbox1" : "value1",
"textbox2" : "value2",
"selectbox1" : [
{ "value" : "1", "text" : "one" },
{ "value" : "2", "text" : "two" },
{ "value" : "3", "text" : "three" }
]
}

So basically, I want to use the selectbox1 part to loop through the arrays and populate the select box.

Please help
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narmi2Asked:
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MorcalavinCommented:
This is a duplicate question.  You already have this question open here: http://www.experts-exchange.com/Programming/Languages/Scripting/JavaScript/JSON/Q_24517811.html

Please close one or the other.
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narmi2Author Commented:
This is a different problem, the problem there was that the loop would not loop which i have not fixed, however, this question the loop will loop, but fills the select box will undefined values.
0
MorcalavinCommented:
The below works fine for me.  Where is 'results' variable coming from?  Is it from an ajax request?

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
<html xmlns="http://www.w3.org/1999/xhtml" >
<head>
</head>
<body>
<select id="names"><option>Default option if JS is disabled</option></select>
<script type="text/javascript">
 
var mySelectBox = document.getElementById('names');
mySelectBox.options.length = 0;
var myData = {"textbox1" : "value1","textbox2" : "value2","selectbox1" : [{ "value" : "1", "text" : "one" },{ "value" : "2", "text" : "two" },{ "value" : "3", "text" : "three" }]}; //this only needs to be eval'ed if it's a string
for(var i = 0, e = myData.selectbox1.length; i < e; ++i) {
    var option = new Option(myData.selectbox1[i].value, myData.selectbox1[i].text);
    mySelectBox.options[i] = option;
}
</script>
</body>
</html>

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narmi2Author Commented:
Yes, the "results" in

objJSON = eval('('+ results +')');

is from an AJAX request which has the value

{
"textbox1" : "value1",
"textbox2" : "value2",
"selectbox1" : [
{ "value" : "1", "text" : "one" },
{ "value" : "2", "text" : "two" },
{ "value" : "3", "text" : "three" }
]
}

So when I eval it and try to loop it into a select box, it gives me lots of undefined values.
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MorcalavinCommented:
Does the ajax data contain those line returns?  If so, you may need to remove the new line characters(start with \n).  I think all the code is working fine.  I think your JSON isn't formatted right and it is being eval'd improperly.

Look here:
http://stackoverflow.com/questions/395379/problem-when-retrieving-text-in-json-format-containing-line-breaks-with-jquery
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MorcalavinCommented:
Hmm..my mad.  You aren't using jquery.  Anyway, the idea should be the same.  Whatever server side script you are using should be replacing the line returns with something javascript can eval properly.
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BadotzCommented:
For all things JSON, visit http://www.json.org
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