Creating Dynamic variables from json response

Question

My JSON response looks like this :

{"sample":[{"id":"2","name":"branch name"},{"id":"3","name":"branch name 2"}]}

My function looks like this :

function getJSONObjects(){
        $.getJSON("http://localhost/api/branches",
        function(data){
          $.each(data.sample, function(i,item){
           var loc = "branch";
           eval("var " + loc + item.id + "=123;");
           alert(loc + item.id);
          });
        });
 }

The idea is to create branch + id object so I can do something with it(create marker on a map), so I tried to assign it any value to see if this was working.

I wanted both branch2 and branch3 to alert 123 so I have something to start with. But currently this alerts branch2 and branch3 instead of 123.

I have little experience with creating dynamic variables/objects can someone tell me what I'm doing wrong or maybe another approach towards solving this?

Ivo Wetzel · Accepted Answer · 2010-12-25 17:39:32Z

3

No idea what you want to do here:

eval("var " + loc + item.id + "=123;"); // eval is EVIL
alert(loc + item.id); // just creates a string...

Creating dynamic variables is a bad idea. Rather create an object and use key/values.

var branches = {}; // new object, move this to the scope you want to access the value from later
branch[item.id] = 123; // set the key 'item.id' to the value '123'
console.log(branch[item.id]); // retrieve the value of the key 'item.id'

But if you're doing this you can just as well change the structure of your JSON data to something like this:

{"sample":[{"1": {"name": "branch name1", "value": 123}, "2": {"name": "branch name2", "value": 456}}]}

Then just grab the elements of the array and use them like branches above.

answered Dec 25, 2010 at 17:39

Ivo Wetzel

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Comments

scoffey · Accepted Answer · 2010-12-25 17:48:30Z

0

Try the following function to iterate data.sample:

function(i,item){
       window[loc + item.id] = 123;
       alert(window[loc + item.id]);
}

The window object here is used to set a global variable, "dynamically" named on runtime. (This is not a good practice, though.)

If loc = 'branch' and item.id = 2, the alert(window[loc + item.id]) statement would be equivalent to alert(branch2).

answered Dec 25, 2010 at 17:48

scoffey

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