How to efficiently search specific values in array using JavaScript

Question

Im wondering how to search big arrays using JavaScript.

Let's say we have an array consisting of elements that represent businesses. There are a couple thousand elements in the array, they are objects that sometimes also have arrays in them.

In each of those elements is a key eg called category that looks like this category: ["attr1", "attr2", "attr3"] . Now I only want to find elements of the array that have a category like this:

category: ["Restaurant"]

The problem is that other keys of the elements in the array sometimes also have a property where "Restaurant" is in the name followed by something else eg "RestaurantPrice" so

if(array[i].categories != null && 
array[i].categories.indexOf("Restaurant") != -1) {
    do something
}

Would not work properly because it would return all occurences of the word "Restaurant" or am I wrong?

If not how should I search for specific things in an array?

Answer 1

If categories is an array like ["foobar", "foo"]

categories.indexOf("foo") would return 1 , foobar would be ignored.

The other question was how to find elements efficient? .

It depends, if your set is static, you can prebuilt and cache some sort of index like:

var categoriesMap = {
  foobar: [1, 2, 4],
  foo: [1, 5, 7]
}

The array would represent the indexes of items, which includes the given categories.

Answer 2

如果您的键是唯一的，请尝试使用HashMaps。