lodash检索对象的属性和对应的值

varusers= {
'barney':  { 'age': 36, 'active': true },
'fred':    { 'age': 40, 'active': false },
'pebbles': { 'age': 1,  'active': true }
};
_.findKey(users, function(o) { returno.age<40; });
// => 'barney' (iteration order is not guaranteed)// The `_.matches` iteratee shorthand._.findKey(users, { 'age': 1, 'active': true });
// => 'pebbles'// The `_.matchesProperty` iteratee shorthand._.findKey(users, ['active', false]);
// => 'fred'// The `_.property` iteratee shorthand._.findKey(users, 'active');
// => 'barney'