getting the index of given object inside of the array

Question

Why I can't get the index of given object inside of the array?

var Sentences = {

    1: {

        sentence: [

            {
                reference: "1",
            },

            {
                reference: "2",
            },

            {
                reference: "3",
            },

            {
                reference: "4",
            },

            {
                reference: "5",
            },
        ],
    },
}


const data = 
{
reference: "3",
}

const sentenceIndex = Sentences[1].sentence.indexOf(data);

console.log(sentenceIndex);

The desired result would be 2 apparently...

`data` is not the same object reference as the one in the array. — Heretic Monkey, Feb 08 '21 at 14:40
because `indexOf` uses `==` as comparison. And that will never be true for two different objects (ie not pointing to the same memory location) — derpirscher, Feb 08 '21 at 14:40

score 2 · Answer 1 · answered Feb 08 '21 at 14:39

Use the findIndex method and check the reference property.

var Sentences = {
  1: {
    sentence: [
      {reference: "1",},
      {reference: "2",},
      {reference: "3",},
      {reference: "4",},
      {reference: "5",},
    ],
  },
}


const data = {reference: "3"}

const sentenceIndex = Sentences[1].sentence.findIndex(({
  reference
}) => reference === data.reference);

console.log(sentenceIndex);

getting the index of given object inside of the array

1 Answers1