Searching array with multiple keys

Question

I can see this works fine for searching a simple array:

var arr1 = ['a','b','c','d','e'];
var index1 = arr1.indexOf('d');
console.log("index1:" + index1); // index1:3

When I try to do the same thing for a different kind of array, it doesn't find the "jane" value:

var arr2 = [{"id":0,"name":"petty"},{"id":1,"name":"jane"},{"id":2,"name":"with"}];
var index2 = arr2.indexOf('jane');
console.log("index2:" + index2); // index2:-1

Sorry - I realise I am probably missing something obvious. I have searched on SO / google for searching multi dimensional arrays, but I don't even know if the array in the 2nd example is a 2d / multi dimensional array, so I am probably not searching for the right thing.

Possible duplicate of [How to get index of object by its property in javascript](https://stackoverflow.com/questions/7176908/how-to-get-index-of-object-by-its-property-in-javascript) — Peter B, Aug 22 '17 at 10:58
`arr2` is not multi dimensional array but it is array of objects, notice the `{}`, it means object. — Hassan Imam, Aug 22 '17 at 10:59

score 1 · Accepted Answer · answered Aug 22 '17 at 10:58

1

You can use findIndex() method to find index of object with specific value.

var arr = [{"id":0,"name":"petty"},{"id":1,"name":"jane"},{"id":2,"name":"with"}];

var index = arr.findIndex(e => e.name == 'jane')
console.log("index: " + index);

answered Aug 22 '17 at 10:58

Nenad Vracar

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I'd like to note that `findIndex` was added only in ECMAScript 2015, and it is not compatible with some browsers (esp. Internet Explorer). See https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/Array/findIndex – Peter B Aug 22 '17 at 11:01

score 0 · Answer 2 · answered Aug 22 '17 at 10:59

First of all: it's not a multi-dimensional array. It's an array consisting of objects. It's one-dimensional. To find an object you need to iterate through an array and check the needed key, e.g.:

arr.findIndex(function(el) { return el.name === 'jane' })

score 0 · Answer 3 · answered Aug 22 '17 at 11:00

0

You could check all values of the objects and use Array#findIndex instead of Array#indexOf.

var arr2 = [{ id: 0, name: "petty" }, { id: 1, name: "jane" }, { id: 2, name: "with" }],
    index2 = arr2.findIndex(o => Object.values(o).some(v => v === 'jane'));

console.log(index2);

answered Aug 22 '17 at 11:00

Nina Scholz

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Nested iterators/generators seem pretty inefficient, as Nenad already posted. This will be better: `arr.findIndex(e => e.name == 'jane')` – Jonas Libbrecht Aug 22 '17 at 11:03
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@JonasLibbrecht, right, but only if you know the key in advance. – Nina Scholz Aug 22 '17 at 11:04
@ Nina Scholz, that's correct but then you are performing a needle in a haystack search and that's basically inefficient on it's own and should not be implemented like this. That issue would be better solved with binary trees or something else. – Jonas Libbrecht Aug 22 '17 at 11:07

score 0 · Answer 4 · answered Aug 22 '17 at 11:07

0

var arr = [{"id":0,"name":"petty"},{"id":1,"name":"jane"},{"id":2,"name":"with"}];
arr.findIndex((item)=>{return item.name=="petty"})
//output is 0

answered Aug 22 '17 at 11:07

Vinod kumar G

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Searching array with multiple keys

4 Answers4