string to JSON parse , javascript runtime invalid character

In your code, data is not a string. It is an array. It does not need parsing (other than by the JavaScript compiler). Just discard $.parseJSON and work with the data.

data = [{'title' : 'location 1','lat' : '29.769730','lng' : '-95.257181','desc' : 'Apartments',},{'title' : 'location 2','lat' : '29.852264','lng' : '-95.469999','desc' : 'location description',},];

data.forEach(o => console.log(o.title));

It is being returned from an mvc5 controller method as a string

If your code does not accurately reflect the data you have and you do have a string, then it would need parsing.

The code you provided is, however, not valid JSON which:

• Requires strings be quoted with " not '
• Does not allow trailing , after the last item in an array.

You need to fix the server side code so it returns real JSON.

This will probably involve replacing some code which attempts to generate JSON by mashing together strings with some which uses a JSON aware library function (see this question).

Your JSON is invalid, try this:

var data = '[{"title" : "location 1","lat" : "29.769730","lng" : "-95.257181","desc" : "Apartments"},{"title" : "location 2","lat" : "29.852264","lng" : "-95.469999","desc" : "location description"}]';

var test = $.parseJSON(data);

validate your JSON here

[{"title" : "location 1","lat" : "29.769730","lng" : "-95.257181","desc" : "Apartments"},{"title" : "location 2","lat" : "29.852264","lng" : "-95.469999","desc" : "location description"}]