Question

For the following tree

var items = {
  'drinks': [
    {
      'name': 'coke',
      'sugar': '1000'
    },
    {
      'name': 'pepsi',
      'sugar': '900'
    }
  ]
};

Is there a way to do something like

function get_values(data) {
  var items = JSON.parse(items)
  return items.data[0].name;
}
get_values('drinks');

Answer 1

If you wish to use the contents of a variable as the accessor for a property, you must use array syntax:

myObject[myKey]

In your case, you need something like:

var items = JSON.parse(items)

function get_values(data) {
    return items[data][0].name;
}

get_values('drinks');  // returns "coke"

Note that this is specifically only returning the name of the first element in the array items.drinks.