Question

Can not parse json using this

var res = eval('(' + response + ')');

The response contain [{"total_sections":"3"}] this value. But i couldn’t take the value total_sections.

function changeSection() { 
   id = document.getElementById('layoutDropdown').value; 
   $.ajax({ type: "POST",
            url:'/manage',
            data: {id : id },
            success: function(response){ 
                  alert(response); 
                  var res = eval(response);
                  alert(res[0].total_sections);                     
            } 
    }); 
} 

manage Layouts:

public function manageLayouts() { 
      $id = $_POST['id']; 
      $data = $this->managelayoutmodel->getSections($id);
      echo json_encode($data);
}

Answer 1

If response is a string you can parse the json with var res = eval(response); (but it isn’t nice), var res = JSON.parse(response); or if you use jQuery var res = $.parseJSON(response). Otherwise if it is already an object you don’t need to parse it, only set var res = response;.
Now you can get the total sections by calling res[0].total_sections, e.g. you can test it with alert(res[0].total_sections);.