haveSameContents javascript

haveSameContents.js

const haveSameContents = (a,b) => {
    for(const v of new Set([...a, ...b]))
        if (a.filter(e => e === v).length !== b.filter(e => e===v).length)
            return false;
        return true;
};

console.log(haveSameContents([1,2,4], [2,4,1]));

const isNumber = val => typeof val === 'number' && val === val;

console.log(isNumber(1));
console.log(isNumber('1'));
console.log(isNumber(NaN));