Optimise logic to partially match 2 array items-CodePudding

I have two arrays and want to match them partially( i.e. some elements of the first array should be present in the second array but not all). I have a solution but I feel I could use a more efficient one. Here is the use case:

const array_1 = [ 7, 6 ];
const array_2 = [ 4, 6 ,7, 2, 9 ];

const isSomeItemMatched = array_1.some( item => array_2.includes(item) );
const isAllItemMatched = array_1.every( item => array_2.includes(item) );

const isPartiallyMatched = !isAllItemMatched && isSomeItemMatched;

Please let me know if there is an optimized way of doing it.

CodePudding user response：

Your solution is fine for small arrays. If they get larger, you'll benefit from turning one into a set:

const array_1 = [ 7, 6 ];
const array_2 = [ 4, 6 ,7, 2, 9 ];

function isPartialMatch(a, b) {
    const setA = new Set(a);
    return b.some(x => setA.has(x)) && b.some(x => !setA.has(x));
}

console.log(isPartialMatch(array_1, array_2));