For simple array members like that, you can use JSON.parse.

var array = JSON.parse("[" + string + "]");

This gives you an Array of numbers.

[0, 1]

If you use .split(), you'll end up with an Array of strings.

["0", "1"]

Just be aware that JSON.parse will limit you to the supported data types. If you need values like undefined or functions, you'd need to use eval(), or a JavaScript parser.

If you want to use .split(), but you also want an Array of Numbers, you could use Array.prototype.map, though you'd need to shim it for IE8 and lower or just write a traditional loop.

var array = string.split(",").map(Number);

To parse it you need to use double quotes instead of single.

This should work:

services = '["service1", "service2", "service3"]'
JSON.parse(services)

If value is not a plain array, such code will work fine:

var value = { "aaa": "111", "bbb": "222", "ccc": "333" };
var blkstr = [];
$.each(value, function(idx2,val2) {                    
  var str = idx2 + ":" + val2;
  blkstr.push(str);
});
console.log(blkstr.join(", "));

<script src="https://ajax.googleapis.com/ajax/libs/jquery/1.7.1/jquery.min.js"></script>

(output will appear in the dev console)

As Felix mentioned, each() is just iterating the array, nothing more.