JSFiddle - React, Tailwind, and code Playground

JavaScript

var json = {
"layout":0,
"caption":"Work History",
"cols":[
   {"field":"company","label":"Company Name","hidden":false,"order":-1,"validationType":2,"list":[]},       {"field":"date_start","label":"From","hidden":false,"order":-1,"validationType":1,"list":[]},
   {"field":"date_end","label":"Until","hidden":false,"order":-1,"validationType":0,"list":[]},
   {"field":"position","label":"Title","hidden":false,"order":-1,"validationType":2,"list":[]},
   {"field":"description","label":"Description","hidden":false,"order":-1,"validationType":0,"list":[]},
   {"field":"project","label":"Project","hidden":false,"order":-1,"validationType":64,"list":[]}
   ]
};

for (var c in json.cols) {
    if( json.cols.hasOwnProperty(c) ) {
      console.log("col name: " + c);
    }
}