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Lodash _.flatten


The lodash _.flatten method is a utility function that takes an array and flattens it into a single-dimensional array. It does this by recursively iterating through the array and concatenating any sub-arrays it encounters.

The method has a single parameter, which is the array to be flattened. It returns a new array containing all the elements of the original array, but with any sub-arrays flattened. The original array is not modified.

The _.flatten method can be used with arrays of any depth, meaning that it can flatten arrays that contain both nested arrays and objects. It also supports the option to flatten only the first level of nested arrays, by passing a depth argument.

Here is an example of how to use the _.flatten method:

const nestedArray = [1, [2, [3, [4]], 5]];

const flattenedArray = _.flatten(nestedArray);

// Output: [1, 2, 3, 4, 5]

In this example, the nestedArray contains both sub-arrays and sub-objects. The _.flatten method is used to create a flattened array flattenedArray that contains all the elements of the original array, but with any sub-arrays flattened.

Overall, the _.flatten method is a useful utility function for working with nested arrays and objects, allowing developers to easily flatten complex data structures into a more simple and manageable format.