Iterating over nested Json array

Question

New in json and js, so I would appriciate if someone would teach me a bit. Json array:

var info = [
{"t":"09:00","b":"Vaba"},
{"t":"09:30","b":"Vaba"}  ] ;

And JS part:

var output='';      
for (var i = 0; i <= info.length; i++) {
    for (info.t of info[i] ) {
        output += '<option> '  + info[i].t + ' ' + info[i].b + '</option>';  } };

    var update = document.getElementById('start_time');
    update.innerHTML = output;

The result I get in HTML looks like this:

<option>9.00 Vaba</option>
<option>9.00 Vaba</option>
<option>9.30 Vaba</option>
<option>9.30 Vaba</option>

This is the only working solution I have found so far, but I don't need a double list (time and text string twice). Writing any function instead of second for loop ends with error info[i] undefined...

Thanks ahead.

What do you want to know? Can you post the code which throws error for you? — Vandesh
– Vandesh, Commented Oct 7, 2013 at 14:29

Bucket · Accepted Answer · 2013-10-07 14:26:04Z

1

Just remove your extra for loop. Also be careful about referencing an out-of-bounds index in info. When i = info.length, info[i] is out of bounds. Just make sure it never gets that far:

var output='';      
for (var i = 0; i < info.length; i++) {
    output += '<option> '  + info[i].t + ' ' + info[i].b + '</option>';  
}

var update = document.getElementById('start_time');
update.innerHTML = output;

answered Oct 7, 2013 at 14:26

Bucket

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Anand Jha · Accepted Answer · 2013-10-07 15:12:10Z

0

Try this ,It will take less execution time and also will take care of memory.

var optionList=[];  
var len= info.length;   
for (var i = 0; i < len; i++) {
    optionList.push('<option> '  + info[i].t + ' ' + info[i].b + '</option>');  
}

var update = document.getElementById('start_time');
update.innerHTML = optionList.join('');

answered Oct 7, 2013 at 15:12

Anand Jha

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1 Comment

Anand Jha Over a year ago

Avoid concatenation of string(it takes more memory) and in the for loop we need not to calculate length of info object(Array) for each iteration so, execution time will be less.

user2854901 · Accepted Answer · 2013-10-08 15:23:25Z

0

Thank you all for response, the final solution was jquery each()

answered Oct 8, 2013 at 15:23

user2854901

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