How to check if an object is empty

1. Convert the object to a string to determine whether it is {}

var data = {};

if(JSON.stringify(data) == '{}'){

return true;

}

2. for in loop judgment
 var data = {};
function isEmptyObj(data){
 for(var a  in data){
    return false;
 }
  return true;
}

　　

3. isEmptyObject method of jquery
This method is jquery encapsulates 2 methods (for in), and needs to rely on jquery when using it
var data = {};
var b = $.isEmptyObject(data);
alert(b);//true

　　

4. Object.keys() method of ES6
var data = {};
var arr = Object.keys(data);
alert(arr.length == 0);//true