문제 링크 : Is Object Empty
/**
* @param {Object | Array} obj
* @return {boolean}
*/
var isEmpty = function(obj) {
let emptyChk = true
for(let key in obj){
if(key !== undefined || key !== null || key !== '') emptyChk = false
}
return emptyChk
};
/**
* @param {Object | Array} obj
* @return {boolean}
*/
var isEmpty = function(obj) {
return Object.keys(obj).length === 0
};