Encountering a problem with TypeScript dictionary

Question

Encountering a problem with TypeScript dictionary

I have created a TypeScript dictionary using the following code:

const skills = x
        .map(y => y.skills)
        .flat(1)
        .map(z => {
          return { [z.id]: { skill: z } };
        });

This is the resulting array from the code above:

{ 7ff2c668-0e86-418a-a962-4958262ee337: {skill: {…}} }
{ c6846331-2e11-45d6-ab8d-306c956332fc: {skill: {…}} }
{ 0fc0cb61-f44d-4fd0-afd1-18506380b55e: {skill: {…}} }
{ 36dc0b74-84ee-4be2-a91c-0a91b4576a21: {skill: {…}} }

The problem I am facing is that I cannot access the dictionary by key:

const id = '7ff2c668-0e86-418a-a962-4958262ee337';
const one = myArr.find(x => x === id); // returns undefined
const two = myArr[id]; // returns undefined

Does anyone have any suggestions on how to resolve this issue?

javascript arrays typescript object

Answer 1

Answer №1

To retrieve the key of each object within your array, you can utilize the Object.keys() method. In this scenario, the key for each object is its id. You can then use this key to check if it matches with a specific id (in this case, x).

Here's an example to illustrate:

const myArr = [
{"7ff2c668-0e86-418a-a962-4958262ee337": {skill: 1}},
{"c6846331-2e11-45d6-ab8d-306c956332fc": {skill: 2}},
{"0fc0cb61-f44d-4fd0-afd1-18506380b55e": {skill: 3}},
{"36dc0b74-84ee-4be2-a91c-0a91b4576a21": {skill: 4}}],
id = "36dc0b74-84ee-4be2-a91c-0a91b4576a21",
index = myArr.findIndex(x => Object.keys(x)[0] === id); // find the index of the object with the matching key

myArr[index] = {newKey: "newValue"}; // set a new value for the object found at the index
console.log(myArr);

Answer 2

To retrieve the key of each object within your array, you can utilize the Object.keys() method. In this scenario, the key for each object is its id. You can then use this key to check if it matches with a specific id (in this case, x).

Here's an example to illustrate:

const myArr = [
{"7ff2c668-0e86-418a-a962-4958262ee337": {skill: 1}},
{"c6846331-2e11-45d6-ab8d-306c956332fc": {skill: 2}},
{"0fc0cb61-f44d-4fd0-afd1-18506380b55e": {skill: 3}},
{"36dc0b74-84ee-4be2-a91c-0a91b4576a21": {skill: 4}}],
id = "36dc0b74-84ee-4be2-a91c-0a91b4576a21",
index = myArr.findIndex(x => Object.keys(x)[0] === id); // find the index of the object with the matching key

myArr[index] = {newKey: "newValue"}; // set a new value for the object found at the index
console.log(myArr);

Answer 3

Answer №2

Instead of creating an array of objects, I recommend creating a single object with your ids as keys.

For instance:

const skills = x
    .map(y => y.skills)
    .flat(1)
    .reduce((acc, z) => {
        acc[z.id] = z;
        return acc;
    }, {});

Your myArr will be structured like this:

{
    '7ff2c668-0e86-418a-a962-4958262ee337': {...}
    'c6846331-2e11-45d6-ab8d-306c956332fc': {...},
    '0fc0cb61-f44d-4fd0-afd1-18506380b55e': {...},
    '36dc0b74-84ee-4be2-a91c-0a91b4576a21': {...}
}

You can then access the objects as intended:

const skill = myArr['7ff2c668-0e86-418a-a962-4958262ee337'];

Answer 4

Instead of creating an array of objects, I recommend creating a single object with your ids as keys.

For instance:

const skills = x
    .map(y => y.skills)
    .flat(1)
    .reduce((acc, z) => {
        acc[z.id] = z;
        return acc;
    }, {});

Your myArr will be structured like this:

{
    '7ff2c668-0e86-418a-a962-4958262ee337': {...}
    'c6846331-2e11-45d6-ab8d-306c956332fc': {...},
    '0fc0cb61-f44d-4fd0-afd1-18506380b55e': {...},
    '36dc0b74-84ee-4be2-a91c-0a91b4576a21': {...}
}

You can then access the objects as intended:

const skill = myArr['7ff2c668-0e86-418a-a962-4958262ee337'];

Answer 5

Answer №3

Utilize the power of maps for better efficiency,

Map is a modern data structure introduced in ES6, allowing you to store key-value pairs similar to languages like Java and C#.

let map = new Map();
const skills = x
        .map(y => y.skills)
        .flat(1)
        .map(z => {
          map.set(z.Id,  { skill: z })
          return  map;
        });

//Access entries
map.get("7ff2c668-0e86-418a-a962-4958262ee337");     //40

//Check if entry exists
map.has("7ff2c668-0e86-418a-a962-4958262ee337");       //true

Answer 6

Utilize the power of maps for better efficiency,

Map is a modern data structure introduced in ES6, allowing you to store key-value pairs similar to languages like Java and C#.

let map = new Map();
const skills = x
        .map(y => y.skills)
        .flat(1)
        .map(z => {
          map.set(z.Id,  { skill: z })
          return  map;
        });

//Access entries
map.get("7ff2c668-0e86-418a-a962-4958262ee337");     //40

//Check if entry exists
map.has("7ff2c668-0e86-418a-a962-4958262ee337");       //true

Encountering a problem with TypeScript dictionary

Answer №1

Answer №2

Answer №3

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