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findKey

_.findKey(predicate, object) # Ⓢ [Ⓣ][1] Ⓝ

This method is like _.find except that it returns the key of the first



element predicate returns truthy for instead of the element itself.

Since​

1.1.0

Arguments​

  1. predicate (Function): The function invoked per iteration.
  2. object (Object): The object to inspect.

Returns​

(*): Returns the key of the matched element,



else undefined.

Example​

var users = {
  'barney':  { 'age': 36, 'active': true },
  'fred':    { 'age': 40, 'active': false },
  'pebbles': { 'age': 1,  'active': true }
};

_.findKey(function(o) { return o.age < 40; }, users);
// => 'barney' (iteration order is not guaranteed)

// The `_.matches` iteratee shorthand.
_.findKey({ 'age': 1, 'active': true }, users);
// => 'pebbles'

// The `_.matchesProperty` iteratee shorthand.
_.findKey(['active', false], users);
// => 'fred'

// The `_.property` iteratee shorthand.
_.findKey('active', users);
// => 'barney'