function filter(array, value, key) {
return array.filter(key
? a => a[key] === value
: a => Object.keys(a).some(k => a[k] === value)
);
}
var a = [{ name: 'xyz', grade: 'x' }, { name: 'yaya', grade: 'x' }, { name: 'x', frade: 'd' }, { name: 'a', grade: 'b' }];
console.log(filter(a, 'x'));
console.log(filter(a, 'x', 'name'));
const filteredList = stories.filter(story => story.title.toLocaleLowerCase().includes(searchTerm.toLocaleLowerCase()));