Can I use js to determine the json empty object?

1. The simplest method is to determine whether there is a corresponding attribute. Of course, it cannot be determined whether it is empty.

[javascript] view plain copy

print?
var dd={yy:""};  
   if(dd&&dd.yy!=""){  
       alert("dd不为空")  
   }  
   else{  
       alert("dd为空")  
   }

2. Determine by parsing json into a string function [ You can also use this to determine whether the backend is passing an array or an object]

[javascript] view plain copy

print?
var a={};  
ar b=new Object();  
console.log("对象字面量的比较结果："+(JSON.stringify(a)=="{}"))  
onsole.log("构造函数的比较结果："+(JSON.stringify(b)=="{}"))

3. Judge by traversing, if there is an attribute, just return false directly and break at the same time Interrupt traversal

[javascript] view plain copy

print?
var a={};  
var b=new Object();  
function isEmptyObject(obj){  
       for(var key in obj){  
          break;  return false  
     };  
     return true  
};  
if(isEmptyObject(a)){  
      alert("对象为空")  
}  
if(isEmptyObject(b)){  
      alert("b是个空对象")  
}

4. Our commonly used jquery also provides a method:

$.isEmptyObjec({})

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