키값 목록 뽑아오기

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]]);
}