循环

var obj = { age: 18, fname: "Rand ", lname: "McKinnon" };function showProps(obj, objName) {    var result = "";    for (var prop in obj) {        result += objName + "." + prop + " = " + obj[prop] + "\n";    }    return result;}console.log(showProps(obj, "person"));

var obj = { age: 18, fname: "Rand ", lname: "McKinnon" };Object.getOwnPropertyNames(obj).forEach(function (i, value) { console.log(i + ":" + value + "\n") });

Object.keys(obj).forEach(function(i,value){console.log(i+":"+value+"\n")});