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

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!

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" }]