Lodash _.flatMapDeep() Method

Lodash _.flatMapDeep() method creates a flattened array of values by running each element in the given collection through the iteratee function and recursively flattens the mapped results. It is similar to the _.flatMap() method.

Syntax:

_.flatMapDeep(collection, iteratee);

Parameters:

• collection: It is the collection to iterate over.
• iteratee: It is the function that is invoked per iteration.

Return Value:

This method returns the new flattened array.

Example 1: In this example, we are using the _.flatMapDeep() method for duplicating the elements of a given array.

Output:

[
 'aaa', 'aaa', 'bbb', 'bbb',
 'ccc', 'ccc', 'ddd', 'ddd',
 'eee', 'eee'
]

Example 2: In this example, we are using the _.flatMapDeep() method for naking apatter of a given array.

Output:

[
 1, '1>', 2, '2>',
 3, '3>', 4, '4>',
 5, '5>', 6, '6>',
 7, '7>'
]
[
 '<a', 'a', '<b',
 'b', '<c', 'c',
 '<d', 'd', '<e',
 'e'
]