How to delete key by function

Question

the object :

const item = {id:1}

the function:

 // get is function, it can be _id or something else
    const getId = (item) => item.id
    const doSomthing = (obj, getId ) =>{
        // here i wont to delete id from obj. 
    }

So, there is an option to delete id key?

delete getId(item)

Here is example of what i wont, so there is some way to do that?

`delete item.id`, maybe inside a function called `deleteId`? — Sergiu Paraschiv, Feb 28 '19 at 15:52
@daniel actually `getId` does return a Reference according to the spec, so it would theoretically be possible this way, if the semantics of `delete` where different. — Jonas Wilms, Feb 28 '19 at 16:01
I got error in typescript The operand of a delete operator must be a property reference, so i understand that is by val — yantrab, Feb 28 '19 at 16:04
@daniel https://stackoverflow.com/questions/13124417/real-world-examples-of-ecmascript-functions-returning-a-reference — Jonas Wilms, Feb 28 '19 at 16:05
"there is no provision for a user-defined function to return a reference." — Daniel A. White, Feb 28 '19 at 16:09
@yantrab what you want to achieve is impossible.Everything that is possible is listed in the dupe — Jonas Wilms, Feb 28 '19 at 16:18
@daniel sorry, my bad, I've missed that detail (the function call semantics do turn the reference into a value before returning that, and I skipped exactly that part) however what the OP is asking is not that far fetched as it seems, with some slight changes in the spec this is actually possible (but would still make little sense) — Jonas Wilms, Feb 28 '19 at 16:23

Joe Warner · Answer 1 · 2019-03-01T13:06:34.173

const item = {id:1, name: 'Joe', age: 23}
const item2 = {id:2}

const removeProp = (item, key) => {
  key instanceof Array ?
    key.forEach(k => delete item[k]) :
    delete item[key]

  return item;
}

const deleteIdES7 = ({ id, ...rest }) => rest;

const deleteId = (item) => removeProp(item, 'id')

console.log('id deleted', deleteId(item))
console.log('id deleted es7', deleteIdES7(item2))
console.log('strip the rest', removeProp(item, ['age', 'name']))

How to delete key by function

1 Answers1