Underscore.js Functions Complete Reference Last Updated : 23 Jul, 2025 Comments Improve Suggest changes Like Article Like Report 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 provides a number of functions that can be applied to the elements. These include the ability to bind a function to an object, wrap a function inside another function, memorize a given function by caching the result computed by the function, apply partially a function by filling in any number of its arguments, without changing its dynamic value and many other wonderful functionalities. The complete reference for underscore functions is provided below: Function Description _.bind()It is used to bind a function to an object. _.bindAll()It is used to bind the number of methods on the object. _.partial()It applies a function by filling in any number of its arguments, without changing its dynamic value. _.memoize()It is used to memorize a given function by caching the result computed by the function. _.delay()It executes the mentioned function in its argument after waiting for the specified milliseconds. _.defer()It is used to invoke/call a function until the current call stack is cleared. _.throttle()It creates a throttled function that can only call the func parameter once per every wait milliseconds. _.debounce()It is used to create a debounced function. _.once()It is used in conditions where we want a particular function to be executed only a single time. _.after()It creates a wrapper of function which doesn't do anything in the start but from the stated count it starts calling the function. _.before()It is used to call a particular function a particular number of times. _.wrap()It is used to wrap a function inside other function. _.negate()It finds a new negated version of the stated predicate function. _.compose()It returns the composition of the list of functions. _.restArguments()It can receive all the arguments from and beyond the stated startIndex that is collected into a single array. Create Quiz Comment K kartik Follow 0 Improve K kartik Follow 0 Improve Article Tags : JavaScript Web Technologies JavaScript - Underscore.js Explore JavaScript BasicsIntroduction to JavaScript4 min readVariables and Datatypes in JavaScript6 min readJavaScript Operators5 min readControl Statements in JavaScript4 min readArray & StringJavaScript Arrays7 min readJavaScript Array Methods7 min readJavaScript Strings5 min readJavaScript String Methods9 min readFunction & ObjectFunctions in JavaScript5 min readJavaScript Function Expression3 min readFunction Overloading in JavaScript4 min readObjects in JavaScript4 min readJavaScript Object Constructors4 min readOOPObject Oriented Programming in JavaScript3 min readClasses and Objects in JavaScript4 min readWhat Are Access Modifiers In JavaScript ?5 min readJavaScript Constructor Method7 min readAsynchronous JavaScriptAsynchronous JavaScript2 min readJavaScript Callbacks4 min readJavaScript Promise4 min readEvent Loop in JavaScript4 min readAsync and Await in JavaScript2 min readException HandlingJavascript Error and Exceptional Handling6 min readJavaScript Errors Throw and Try to Catch2 min readHow to create custom errors in JavaScript ?2 min readJavaScript TypeError - Invalid Array.prototype.sort argument1 min readDOMHTML DOM (Document Object Model)8 min readHow to select DOM Elements in JavaScript ?3 min readJavaScript Custom Events4 min readJavaScript addEventListener() with Examples9 min readAdvanced TopicsClosure in JavaScript4 min readJavaScript Hoisting6 min readScope of Variables in JavaScript3 min readJavaScript Higher Order Functions7 min readDebugging in JavaScript4 min read Like