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!