Functional Programming Development Tutorials, Guides & Insights

In this example, after arr is set to null, the object { a: 1 } is no longer reachable and will be collected by the garbage collector.

Different JavaScript engines may use various strategies to optimize garbage collection:

Underscore.js is a lightweight utility library similar to Lodash, providing useful functions for working with arrays, objects, and other data types.

<table>
  <tr>
    <th>Function</th>
    <th>Description</th>
    <th>Example</th>
  </tr>
  <tr>
    <td><code>_.each(list, iteratee)
    Iterates over a list, invoking the iteratee for each element.
    _.each([1, 2, 3], alert)
  
  
    _.map(list, iteratee)
    Creates a new array by applying the iteratee to each element in the list.
    _.map([1, 2, 3], num => num * 3) => [3, 6, 9]
  
  
    _.reduce(list, iteratee, memo)
    Reduces a list to a single value by iterating and combining elements.
    _.reduce([1, 2, 3], (sum, num) => sum + num, 0) => 6
  
  
    _.filter(list, predicate)
    Returns an array of elements that pass a truth test.
    _.filter([1, 2, 3, 4], num => num % 2 == 0) => [2, 4]
  
  
    _.findWhere(list, properties)
    Returns the first element that matches the specified properties.
    _.findWhere([{a: 1}, {a: 2}], {a: 2}) => {a: 2}