How to find a value in an array of objects in JavaScript?

Question

I have an array of objects:

Object = {    1 : { name : bob , dinner : pizza },    2 : { name : john , dinner : sushi },    3 : { name : larry, dinner : hummus } } 

I want to be able to search the object/array for where the key is "dinner", and see if it matches "sushi".

I know jQuery has $.inArray, but it doesn't seem to work on arrays of objects. Or maybe I'm wrong. indexOf also seems to only work on one array level.

Is there no function or existing code for this?

Answer 1

If you have an array such as

var people = [   { "name": "bob", "dinner": "pizza" },   { "name": "john", "dinner": "sushi" },   { "name": "larry", "dinner": "hummus" } ]; 

You can use the filter method of an Array object:

people.filter(function (person) { return person.dinner == "sushi" });   // => [{ "name": "john", "dinner": "sushi" }] 

In newer JavaScript implementations you can use a function expression:

people.filter(p => p.dinner == "sushi")   // => [{ "name": "john", "dinner": "sushi" }] 

---

You can search for people who have "dinner": "sushi" using a map

people.map(function (person) {   if (person.dinner == "sushi") {     return person   } else {     return null   } }); // => [null, { "name": "john", "dinner": "sushi" }, null] 

or a reduce

people.reduce(function (sushiPeople, person) {   if (person.dinner == "sushi") {     return sushiPeople.concat(person);   } else {     return sushiPeople   } }, []); // => [{ "name": "john", "dinner": "sushi" }] 

I'm sure you are able to generalize this to arbitrary keys and values!

Answer 2

jQuery has a built-in method jQuery.grep that works similarly to the ES5 filter function from @adamse's Answer and should work fine on older browsers.

Using adamse's example:

var peoples = [   { "name": "bob", "dinner": "pizza" },   { "name": "john", "dinner": "sushi" },   { "name": "larry", "dinner": "hummus" } ]; 

you can do the following

jQuery.grep(peoples, function (person) { return person.dinner == "sushi" });   // => [{ "name": "john", "dinner": "sushi" }]