contains()

The contains method determines whether the collection contains a given item:

const collection = collect({
  name: 'Mohamed Salah',
  number: 11,
});

collection.contains('name');
// true

collection.contains('age');
// false

collection.contains('Mohamed Salah');
// true

You may also work with arrays

const collection = collect([1, 2, 3]);

collection.contains(3);
// true

You may also pass a key / value pair to the contains method, which will determine if the given pair exists in the collection:

const collection = collect({
  name: 'Mohamed Salah',
  number: 11,
});

collection.contains('name', 'Steve Jobs');
// false

Finally, you may also pass a callback to the contains method to perform your own truth test:

const collection = collect([1, 2, 3, 4, 5]);

collection.contains((value, key) => value > 5);

// false

View source on GitHub