Check if an array contains any element of another

Question

I have a target array ["apple","banana","orange"], and I want to check if other arrays contain any one of the target array elements.

For example:

["apple","grape"] //returns true;

["apple","banana","pineapple"] //returns true;

["grape", "pineapple"] //returns false;

How can I do it in JavaScript?

Answer 1

Adding to Array Prototype

Disclaimer: Many would strongly advise against this. The only time it'd really be a problem was if a library added a prototype function with the same name (that behaved differently) or something like that.

Code:

Array.prototype.containsAny = function(arr) {
    return this.some(
        (v) => (arr.indexOf(v) >= 0)
    )
}

Without using big arrow functions:

Array.prototype.containsAny = function(arr) {
    return this.some(function (v) {
        return arr.indexOf(v) >= 0
    })
}

Usage

var a = ["a","b"]

console.log(a.containsAny(["b","z"]))    // Outputs true

console.log(a.containsAny(["z"]))    // Outputs false

Answer 2

var target = ["apple","banana","orange"];
var checkArray = ["apple","banana","pineapple"];

var containsOneCommonItem = target.some(x => checkArray.some(y => y === x));`

["apple","grape"] //returns true;

["apple","banana","pineapple"] //returns true;

["grape", "pineapple"] //returns false;

Answer 3

vanilla js

/**
 * @description determine if an array contains one or more items from another array.
 * @param {array} haystack the array to search.
 * @param {array} arr the array providing items to check for in the haystack.
 * @return {boolean} true|false if haystack contains at least one item from arr.
 */
var findOne = function (haystack, arr) {
    return arr.some(function (v) {
        return haystack.indexOf(v) >= 0;
    });
};

Answer 4

Using filter/indexOf:

function containsAny(source,target)
{
    var result = source.filter(function(item){ return target.indexOf(item) > -1});   
    return (result.length > 0);  
}    


//results

var fruits = ["apple","banana","orange"];


console.log(containsAny(fruits,["apple","grape"]));

console.log(containsAny(fruits,["apple","banana","pineapple"]));

console.log(containsAny(fruits,["grape", "pineapple"]));

Answer 5

You can use a nested Array.prototype.some call. This has the benefit that it will bail at the first match instead of other solutions that will run through the full nested loop.

eg.

var arr = [1, 2, 3];
var match = [2, 4];

var hasMatch = arr.some(a => match.some(m => a === m));

Answer 6

Vanilla JS with partial matching & case insensitive

The problem with some previous approaches is that they require an exact match of every word. But, What if you want to provide results for partial matches?

function search(arrayToSearch, wordsToSearch) {
    arrayToSearch.filter(v => 
        wordsToSearch.every(w => 
            v.toLowerCase().split(" ").
                reduce((isIn, h) => isIn || String(h).indexOf(w) >= 0, false)
            )
        )
}
//Usage
var myArray = ["Attach tag", "Attaching tags", "Blah blah blah"];
var searchText = "Tag attach";
var searchArr = searchText.toLowerCase().split(" "); //["tag", "attach"]

var matches = search(myArray, searchArr);
//Will return
//["Attach tag", "Attaching tags"]

This is useful when you want to provide a search box where users type words and the results can have those words in any order, position and case.