Javascript, how to add an object to an array, if some properties of this object dont already exist in the array

Question

I have the following array (name is always random)

array =
[
{
active: true,
field1: "100",
field2: "",
field3: "1",
name: 0.0020123,
ventasAnuales: "ventasAnuales",
slActive: true
},
{
active: true,
field1: "100",
field2: "",
field3: "1",
name: 0.0020123,
ventasAnuales: "ventasAnuales",
slActive: true
},
{
active: true,
field1: "100",
field2: "",
field3: "1",
name: 0.0020123,
ventasAnuales: "ventasAnuales",
slActive: true
},
{
active: true,
field1: "100",
field2: "",
field3: "1",
name: 0.0020123,
empleados: "empleados",
slActive: true
}
]

Now I want to add extrao objects to the array, and I do it with a concat

array.concat(a).filter(i => i.active)

Problem is that there are certains conditions I should look for before doing the concat. Like for example

If an object with equal field1 and has the same last but one property ventasAnuales | empleados already exists in the array, but field3 is different. It should replace it

For example, given that I want to add the following object

{
active: true,
field1: "100",
field2: "",
field3: "2",
name: 0.0020423,
ventasAnuales: "ventasAnuales",
slActive: true
},

It would replace the first element of the array

If i add an object with the same field3 value, the same last but one property ventasAnuales | empleados and the field1 is different, it should be replaced by the new object.

For example, given that i want to add the following object.

{
    active: true,
    field1: "50",
    field2: "",
    field3: "1",
    name: 0.1020123,
    ventasAnuales: "ventasAnuales",
    slActive: true
    }

It should end up replacing the first element of the array.

How should i write my concat to make this work?

can you highlight, why you get the item at index zero?

Nina Scholz
– Nina Scholz

2021-02-19 08:26:41 +00:00
Commented Feb 19, 2021 at 8:26 — Nina Scholz
– Nina Scholz, Commented Feb 19, 2021 at 8:26

philipp · Accepted Answer · 2021-02-19 08:30:51Z

1

Just filter the array to find any items that should prevent from insertion. In case you do not find any, add the new item.

you can use [].filter() like so:

const items = […, …, …]
const containing = items.filter(item => item.active == true);
if (containing.length == 0) items.push( … )

but [].every() or [].some() may do as well.

Example with every()

if ( !items.every( i => !i.active )) 
  items.push({ active: false })

In case you need to replace an existing element you can use findIndex() like so:

const items = […, …, …];
const idx = items.findIndex(itm => itm.active);


// create a new item
if (idx < 0) {
  items.push(…)
}
else {
  // update
  items[idx] = …
}

edited Feb 19, 2021 at 8:30

answered Feb 19, 2021 at 8:25

philipp

16.6k15 gold badges66 silver badges121 bronze badges

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

Collectives™ on Stack Overflow

Javascript, how to add an object to an array, if some properties of this object dont already exist in the array

1 Answer 1

Comments

Your Answer

Hot Network Questions

Collectives™ on Stack Overflow

1 Answer 1

Comments

Your Answer

Sign up or log in

Post as a guest

Related