#12 Object에서 Key값 목록 나열하기

var obj = {
	"key1" : "data1",
	"key2" : "data2",
	"key3" : "data3"
};

console.log(obj);

var keys = Object.keys(obj);

console.log(keys);

for ( var i in keys) {
	console.log("key="+keys[i]+ ",  data="+ obj[keys[i]]);
}