Tips for finding the position of a specific object within an array of objects using JavaScript when it is an exact match

Question

Tips for finding the position of a specific object within an array of objects using JavaScript when it is an exact match

I am working with an array of objects and need to find the index of a specific object within the array when there is a match.

Here is an example of my current array:

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
 .....
];

Previously, I was using indexOf to achieve this, but now it is not returning the correct index, instead giving -1.

let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = x.indexOf(find); // should return 1.

The entire object needs to be matched in order to retrieve the correct index. Do you have any suggestions on how I can accomplish this? Should I consider using some()? Your guidance would be greatly appreciated.

Thank you

javascript arrays

Answer 1

Answer №1

Instead of using indexOf, you can opt for .find since two objects are never equal (as they point to different memory references), which seems to be the argument you are passing.

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}}
];

let found = x.find(function(item) {
  // The condition can be implemented here
  return item.info.id === 564;
});

console.log(found);

To retrieve the index, consider using .findIndex method instead.

let x = [
    {name: "emily", info: { id: 123, gender: "female", age: 25}},
    {name: "maggie", info: { id: 234, gender: "female", age: 22}},
    {name: "kristy", info: { id: 564, gender: "female", age: 26}}
];

let foundIndex = x.findIndex(function(item) {
  // The condition can be implemented here
  return item.info.id === 564;
});

console.log(foundIndex);

Answer 2

Instead of using indexOf, you can opt for .find since two objects are never equal (as they point to different memory references), which seems to be the argument you are passing.

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}}
];

let found = x.find(function(item) {
  // The condition can be implemented here
  return item.info.id === 564;
});

console.log(found);

To retrieve the index, consider using .findIndex method instead.

let x = [
    {name: "emily", info: { id: 123, gender: "female", age: 25}},
    {name: "maggie", info: { id: 234, gender: "female", age: 22}},
    {name: "kristy", info: { id: 564, gender: "female", age: 26}}
];

let foundIndex = x.findIndex(function(item) {
  // The condition can be implemented here
  return item.info.id === 564;
});

console.log(foundIndex);

Answer 3

Answer №2

To compare objects in JavaScript, traditional equality cannot be used. Instead, the ES6 findIndex method can be employed to compare each object's properties with desired values. An example is provided below:

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}}
];
let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = x.findIndex(element => element.info.id === find.info.id); // index === 1

In your specific scenario, the id value appears to be a suitable identifier for an object; additional equality checks can be added if more properties need to be compared, using the && operator (e.g., element.name === find.name).

Answer 4

To compare objects in JavaScript, traditional equality cannot be used. Instead, the ES6 findIndex method can be employed to compare each object's properties with desired values. An example is provided below:

let x = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}}
];
let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = x.findIndex(element => element.info.id === find.info.id); // index === 1

In your specific scenario, the id value appears to be a suitable identifier for an object; additional equality checks can be added if more properties need to be compared, using the && operator (e.g., element.name === find.name).

Answer 5

Answer №3

Living in the world of _.lodash makes this process seamless, as lodash excels at handling nested objects by going deep into them:

let data = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, age: 22, gender: "female"}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
];

let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = _.findIndex(data, (i) => _.isEqual(i, find))

console.log(index)  // 1

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

A more brute force method that is not efficient and fails if property order differs.

let data = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
];

var objectJSONs = data.map((i) => JSON.stringify(i))

let myJSON = JSON.stringify({name: "maggie", info: { id: 234, gender: "female", age: 22}});
let index = objectJSONs.indexOf(myJSON)

console.log(index) // 1

Answer 6

Living in the world of _.lodash makes this process seamless, as lodash excels at handling nested objects by going deep into them:

let data = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, age: 22, gender: "female"}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
];

let find = {name: "maggie", info: { id: 234, gender: "female", age: 22}};
let index = _.findIndex(data, (i) => _.isEqual(i, find))

console.log(index)  // 1

<script src="https://cdnjs.cloudflare.com/ajax/libs/lodash.js/4.17.10/lodash.min.js"></script>

A more brute force method that is not efficient and fails if property order differs.

let data = [
{name: "emily", info: { id: 123, gender: "female", age: 25}},
{name: "maggie", info: { id: 234, gender: "female", age: 22}},
{name: "kristy", info: { id: 564, gender: "female", age: 26}},
];

var objectJSONs = data.map((i) => JSON.stringify(i))

let myJSON = JSON.stringify({name: "maggie", info: { id: 234, gender: "female", age: 22}});
let index = objectJSONs.indexOf(myJSON)

console.log(index) // 1

Answer 7

Answer №4

To compare objects, you can utilize the underscore _.isEqual function and implement a looping mechanism such as some() to iterate through the array.

let foundIndex = -1;
let isFound = array.some((element, index) => {
                    if(_.isEqual(element, targetObject){
                        foundIndex = index;
                        return true;
                    }
                    return false;
                  }
 //console.log(foundIndex);

Answer 8

To compare objects, you can utilize the underscore _.isEqual function and implement a looping mechanism such as some() to iterate through the array.

let foundIndex = -1;
let isFound = array.some((element, index) => {
                    if(_.isEqual(element, targetObject){
                        foundIndex = index;
                        return true;
                    }
                    return false;
                  }
 //console.log(foundIndex);

Tips for finding the position of a specific object within an array of objects using JavaScript when it is an exact match

Answer №1

Answer №2

Answer №3

Answer №4

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