Underscore.js is a lightweight JavaScript library and not a complete framework that was written by Jeremy Ashkenas that provides utility functions for a variety of use cases in our day-to-day common programming tasks.
Underscore.js Collection functions are used on arrays, objects, and array-like objects such as arguments, NodeList, and similar other types of elements.
Function | Description |
|---|---|
| _.each() | It returns the each element of the given list. |
| _.map() | It produces a new array of values by mapping each value in list through transformation function. |
| _.reduce() | It creates a single result from a given list of values. |
| _.reduceRight() | It performs operations on each element from the right. |
| _.find() | It looks at each element and returns the first occurrence of the element that satisfy the condition. |
| _.filter() | It checks which elements in the passed array satisfy the condition. |
| _.where() | It finds all the elements that matches the searching condition. |
| _.findWhere() | It is used to have a list of all the elements that matches the given property. |
| _.reject() | It gives the answer which does not match with the given condition. |
| _.every() | It is used to test all the elements of the list can pass the given test. |
| _.some() | It finds whether any value in the given list matches the given condition or not. |
| _.contains() | It checks whether a particular item is given in the list of not. |
| _.invokes() | It is used to perform certain actions on the elements of an array. |
| _.pluck() | It is used when we need to extract a list of a given property. |
| _.max() | It finds the minimum element from the list passed. |
| _.min() | It finds the minimum element from the list passed. |
| _.sortBy() | It sorts all the elements of the list in ascending order according to the function given to it as a parameter. |
| _.groupBy() | It makes a collection of the elements in the array passed. |
| _.indexBy() | It returns a key for each element in the list and then returns an object with an index of each item. |
| _.countBy() | It sorts a list into groups and returns a count for the number of objects in each group. |
| _.shuffle() | It is used to arrange a list of arrays in a random manner. |
| _.toArray() | It creates a real array from the list of items that iterated over the elements. |
| _.size() | It is used to find the size of an array. |
| _.partition() | It is used to get an array as input and returns two arrays. |