How to Truncate an Array in JavaScript? Last Updated : 15 Apr, 2025 Comments Improve Suggest changes Like Article Like Report Here are the different methods to truncate an array in JavaScript1. Using length PropertyIn Array.length property, you can alter the length of the array. It helps you to decide the length up to which you want the array elements to appear in the output. JavaScript const n = [1, 2, 3, 4, 5, 6]; n.length = 3; console.log(n); Output[ 1, 2, 3 ] In this exampleThe array num is initialized with [1, 2, 3, 4, 5, 6].The length property of num is set to 3.This truncates the array to its first three elements: [1, 2, 3].Elements from index 3 onward are removed.2. Using splice() MethodThe splice() method removes items from an array, and returns the removed items. JavaScript const n = [1, 2, 3, 4, 5, 6]; n.splice(4); console.log(n); Output[ 1, 2, 3, 4 ] In this exampleThe array num is initialized with [1, 2, 3, 4, 5, 6].num.splice(4) removes all elements starting from index 4.The elements [5, 6] are removed.The resulting array is [1, 2, 3, 4].3. Using slice() MethodArr.slice() method returns a new array containing a portion of the array on which it is implemented. The original remains unchanged. JavaScript let a = ["Geeks", "Geek", "GFG", "gfg","G"]; a = a.slice(0, 2); console.log(a); Output[ 'Geeks', 'Geek' ] In this exampleThe array is initialized with ["Geeks", "Geek", "GFG", "gfg", "G"].a.slice(0, 2) creates a new array containing elements from index 0 to 1 (excluding index 2), resulting in ["Geeks", "Geek"].4. Using Lodash _.truncate() MethodThe _.truncate() method of String in lodash is used to truncate the stated string if it is longer than the specified string length. JavaScript // Requiring lodash library const _ = require('lodash'); let res = _.truncate( 'GFG is a computer science portal.'); console.log(res); OutputGeeksforGeeks is a computer...In this exampleThe lodash library is required using const _ = require('lodash');._.truncate() is used to shorten the string 'GeeksforGeeks is a computer science portal.' to a default length (typically 30 characters), adding '...' at the end, resulting in 'GeeksforGeeks is a com...'.5. Using Array.prototype.pop() in a loopTo truncate an array using `Array.prototype.pop()` in a loop, iterate backward over the array and use `pop()` to remove elements until the desired length is reached. JavaScript const a = [1, 2, 3, 4, 5]; const len = 3; for (let i = 0; i < a.length - len; i++) { a.pop(); } console.log(a); Output[ 1, 2, 3, 4 ] In this exampleThe array a is initialized as [1, 2, 3, 4, 5] and len is set to 3.The for loop removes the last two elements of a (by calling .pop() twice), resulting in the array [1, 2, 3].6. Using filter() MethodThe filter() method creates a new array with all elements that pass the test implemented by the provided function. By using the index as a condition, you can effectively truncate the array. JavaScript const a = [1, 2, 3, 4, 5, 6]; const trun = a.filter((elem, ind) => ind < 3); console.log(trun); Output[ 1, 2, 3 ] In this exampleThe filter() method is used on the array to create a new array with elements whose index is less than 3.The resulting array trun contains the first three elements: [1, 2, 3].7. Using Proxy Objects to Control Array LengthA Proxy object allows you to define custom behavior for fundamental operations on an object, including arrays. JavaScript const a = [1, 2, 3, 4, 5, 6]; const b = { set: function (tar, prop, val) { if (prop === 'length') { val = Math.max(0, val); tar.length = val; return true; } tar[prop] = value; return true; } }; const proxy = new Proxy(a, b); proxy.length = 3; console.log(proxy); Output[ 1, 2, 3 ] In this exampleconst proxy = new Proxy(arr, handler); creates a Proxy object, wrapping the arr array.The handler(b) object defines a set trap, which intercepts changes to properties of the array.By setting proxy.length = 3;, the array is truncated to its first 3 elements. Comment More infoAdvertise with us Next Article How to Truncate an Array in JavaScript? 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