Delete is not working for javascript object in NodeJs

It looks like the reason you can't delete some of those properties is that they have been defined as "non-configurable." However, your approach is sub-optimal because it necessarily mutates its argument. Never, ever, mutate an argument. Ever.

Rather than delete properties from event, you ought to construct a new object that contains only the properties you desire.

• you can safelist specific properties that you wish to transfer (and save)
• you can blocklist specific properties that you don't wish to save
• you can transfer only those properties that live directly on the object, rather than the prototype chain, using Object.getOwnPropertyNames

Libraries like lodash have sugar for doing this kind of thing:

// safelist (using lodash)var saveableEvent = _.pick(event, ['code', 'event', 'source', 'target', 'params', 'log', 'hits', 'type', 'state', 'testProperty', 'updatedDate', 'creationDate']);// or blocklist (using lodash)var saveableEvent = _.omit(event, ['_id', '__t', '__v']);// only copy object's own properties (without lodash)var saveableEvent = Object.getOwnPropertyNames(event).reduce(function(out, propName) {    return Object.assign(out, event[propName])}, {})// create editable copy of object, then remove undesired propsvar saveableEvent = event.toObject();delete saveableEvent._id;

Did you try lean() when you query?like find(query).lean()... check this http://blog.sandromartis.com/2016/05/08/mongoose-lean/This will allow you to do any operation to the object.

Other way could be extending the root object with removing unwanted properties from it. you can use https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Object/assign

example:

var obj = { a: 1 };var copy = Object.assign({}, obj);console.log(copy); // { a: 1 }delete copy._id;//or whatever you wantconsole.lg(copy);//check this doesnt have the _id;

ThanksHope this helps

I recently had a similar problem. I used loadash to cut off the values I didn't need from the array, but had to use .toObject() in the fetched object so I could use it as an argument. Something like:

let resultExample = _.omit(exampleObject.toObject(), ['x', 'y', 'z']);