Javascript delete object property not working

Question

I\'m running some project on MEAN.js and I\'ve got a following problem. I want to make some user\'s profile calculation and the save it to database. But there\'s a problem w

Answer 1

Just do:

user.password = undefined;

instead of:

delete user.password;

and the password property will not appear at the output.

Answer 2

Had a similar problem. This worked for me:

// create a new copy  
let newUser= ({...user}._doc); 

// delete the copy and use newUser that thereafter. 
delete newUser.password; 

Answer 3

there are certain rules for delete operator in javascript

1. if the property is an own non-configurable property in "strict mode" than it will return false.

for example

x = 42;         // creates the property x on the global object
var y = 43;     // creates the property y on the global object, and marks it as non-configurable

// x is a property of the global object and can be deleted
delete x;       // returns true

// y is not configurable, so it cannot be deleted                
delete y;       // returns false 

2. If the object inherits a property from a prototype, and doesn't have the property itself, the property can't be deleted by referencing the object. You can, however, delete it directly on the prototype.

for example

function Foo(){}
Foo.prototype.bar = 42;
var foo = new Foo();

// returns true, but with no effect, 
// since bar is an inherited property
delete foo.bar;           

// logs 42, property still inherited
console.log(foo.bar);

so, please cross check these point and for more information your can read this Link

Answer 4

Had a similar issue. The delete operator "was not working" when trying to delete a property from an object in a specific case. Fixed it using Lodash unset:

_.unset(user, "password");

https://lodash.com/docs/4.17.11#unset

Otherwise the delete operator does work. Just in case, delete operator docs here: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Operators/delete

Answer 5

The answer above from Majed A is the simplest solution that works for single objects properties, we can even make it for more easier by removing the ...user spreader. just delete the property from your object._doc sub-object. in your example it would have been:

user.save()
delete user._doc.password
res.status(201).json(user) // The password will not be shown in JSON but it has been saved.