Check if Object is empty with JavaScript/jQuery

Question

I have an object like this:

ricHistory = {
  name1: [{
    test1: value1,
    test2: value2,
    test3: value3
  }],
  name2: [{
    test1: value1,
    test2: value2,
    test3: value3
  }]
};

Now I want to check if e.g. name2 is empty with Javascript/jQuery. I know the method hasOwnProperty. It work for data.hasOwnProperty('name2') only if the name exists or not, but I have to check if its empty.

Answer 1

you can do this by jQuery.isEmptyObject()

Check to see if an object is empty (contains no properties).

jQuery.isEmptyObject( object )

Example:

jQuery.isEmptyObject({}) // true
jQuery.isEmptyObject({ foo: "bar" }) // false

from Jquery

Answer 2

Another syntax from JQuery which is you are not using Prototype or similar and you prefer to use $ rather than jQuery prefix;

$.isEmptyObject( object )

Answer 3

Try this:

if (ricHistory.name2 && 
    ricHistory.name2 instanceof Array &&
    !ricHistory.name2.length) {
   console.log('name2 is empty array');
} else {
   console.log('name2 does not exists or is not an empty array.');
}

The solution above will show you whether richHistory.name2 exists, is an array and it's not empty.

Answer 4

Try this useful function:

function isEmpty(obj) {
if(isSet(obj)) {
    if (obj.length && obj.length > 0) { 
        return false;
    }

    for (var key in obj) {
        if (hasOwnProperty.call(obj, key)) {
            return false;
        }
    }
}
return true;    
};

function isSet(val) {
if ((val != undefined) && (val != null)){
    return true;
}
return false;
};