JSFiddle - React, Tailwind, and code Playground

JavaScript

var jsonStr = "{\"state\":[\"Tennessee\"],\"more_data\":[{\"letters\":{\"first\":\"T\",\"last\":\"e\"}}]}";

var jsonObj = JSON.parse(jsonStr);
for (key in jsonObj) {
    console.log(key+':'+JSON.stringify(jsonObj[key]));
}