Is object empty? [duplicate]

Answer 1

here's a good way to do it

function isEmpty(obj) {
  if (Array.isArray(obj)) {
    return obj.length === 0;
  } else if (typeof obj === 'object') {
    for (var i in obj) {
      return false;
    }
    return true;
  } else {
    return !obj;
  }
}

Answer 2

if (Object.getOwnPropertyNames(obj1).length > 0)
{
 alert('obj1 is empty!');
}

Answer 3

You can write a fallback if Array.isArray and Object.getOwnPropertyNames is not available

XX.isEmpty = function(a){
    if(Array.isArray(a)){
        return (a.length==0);
    }
    if(!a){
        return true;
    }
    if(a instanceof Object){

        if(a instanceof Date){
            return false;
        }

        if(Object.getOwnPropertyNames(a).length == 0){
            return true;
        }
    }
    return false;
}

Answer 4

Underscore and lodash each have a convenient isEmpty() function, if you don't mind adding an extra library.

_.isEmpty({});

Answer 5

No need for a library.

function(){ //must be within a function
 var obj = {}; //the object to test

 for(var isNotEmpty in obj) //will loop through once if there is a property of some sort, then
    return alert('not empty')//what ever you are trying to do once

 return alert('empty'); //nope obj was empty do this instead;
}