Obj.lenght and calling methods

var obj = { "1234": "312", "4321": "198", "4231": "211", "3421": "323", "1423": "246" };

var getProp = function (propertyName) { return obj[propertyName]; };

console.log(getProp("1234"));

Object.getLength = function(obj) { var iLength = 0; for (var sKey in obj) { if (obj.hasOwnProperty(sKey)) iLength++; } return iLength; };

let objLeng = Object.getLength(obj);

console.log(obj[Object.keys(obj)[0]]);