Unable to delete empty object properties with javascript and angular

Question

I am using angular 1.6.

I need remove some properties of a javascript object if they are null, empty or undefined.

In my case, i have two empty arrays 'byweekday" and "bymonth" and I am trying to delete them from object, without success.

What am I doing wrong?

//markup

<button class="btn btn-xs btn-success" type="button" 
                     ng-click="makecalc()">
                     Calculate
</button>

//code

//angular controller

     $scope.repeticao={"wkst":1,"freq":{"id":0,"name":"Anualmente"},"byweekday":
   [],"bymonth":[]};

    function removeEmpty(obj) {
      Object.keys(obj).forEach(function(key) {
        if (obj[key] && typeof obj[key] === 'object') removeEmpty(obj[key])
        else if (obj[key] === null || obj[key] === undefined) delete obj[key]
      });
      return obj;
    };
    $scope.makecalc=function(){
          //debugger;
          var key, value, date;
          var values = angular.copy($scope.repeticao);
          values=removeEmpty(values);
          console.log(JSON.stringify(values)); 
    }

Your code only deletes a key when the value is null or undefined not an empty array. — rgthree
– rgthree, Commented Aug 6, 2017 at 20:23
Why don't you create a brand new object inside the removeEmpty() function and assign properties in for loop, then return it? — Radu Nemerenco
– Radu Nemerenco, Commented Aug 6, 2017 at 20:23
Hi, I also tried: if (values.byweekday.length=0) delete values.byweekday; but it doesn't work — Luiz Alves
– Luiz Alves, Commented Aug 6, 2017 at 20:30

rgthree · Accepted Answer · 2017-08-06 20:40:56Z

2

Your code only deletes a key when the value is null or undefined so, obviously, it won't delete an empty array, so you'll need to check for that as well. Since typeof is also "object" you'll need to check for a removable-item first. (Also, using == with null checks for both null and undefined, so we can simplify that as well):

function removeEmpty(obj) {
  Object.keys(obj).forEach(function(key) {
    if (obj[key] == null || (Array.isArray(obj[key]) && obj[key].length === 0)) {
      delete obj[key];
    } else if (typeof obj[key] === 'object') {
      removeEmpty(obj[key]);
    }
  });
  return obj;
};

edited Aug 6, 2017 at 20:40

answered Aug 6, 2017 at 20:25

rgthree

7,28319 silver badges21 bronze badges

Sign up to request clarification or add additional context in comments.

4 Comments

Luiz Alves Over a year ago

Hi, It doesn't work. The array is not been removed

rgthree Over a year ago

@LuizAlves You're right. It's the typeof check, since an array's typeof is "object" you'll need to check for an empty array first. I've updated the answer.

Luiz Alves Over a year ago

Now it´s working. But why the code: " if (values.byweekday.length=0) delete values.byweekday;" doesn´t works?

Luiz Alves Over a year ago

Than you, Mr rgthree

Collectives™ on Stack Overflow

Unable to delete empty object properties with javascript and angular

1 Answer 1

4 Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

4 Comments

Your Answer

Sign up or log in

Post as a guest

Related