How To Add An Item Before A Specified Index In A List In R

ExploreEXPLORE THE CATALOGSupercharge your career with 700+ hands-on coursesView All CoursesPythonJavaJavaScriptCReactDockerVue JSRWeb DevDevOpsAWSC#LEARNING TOOLSExplore the industry's most complete learning platformCoursesLevel up your skillsSkill PathsAchieve learning goalsProjectsBuild real-world applicationsMock InterviewsNewAI-Powered interviewsPersonalized PathsGet the right resources for your goalsLEARN TO CODECheck out our beginner friendly courses.PricingFor BusinessResourcesNewsletterCurated insights on AI, Cloud & System DesignBlogFor developers, By developersFree CheatsheetsDownload handy guides for tech topicsAnswersTrusted answers to developer questionsGamesSharpen your skills with daily challengesSearchCoursesLog InJoin for freeHow to add an item before a specified index in a list in R

Overview

A list in R is simply a collection of ordered and changeable data. A list contains different data types such as strings or numbers. The elements contained in a given list are referred to as the item of the list.

Creating a list

We use the list() function to create a list in R. This function takes the list of items you want on the list as parameters.

Example

# creating a string and numerical listsmylist1 <- list("cherry", 'banana', 'orange') mylist2 <- list(1, 2, 3, 4, 5)# to print the listsmylist1mylist2Run

Code Explanation

We create two list variables mylist1 and mylist2 that have strings and numbers respectively.

Adding an item to the right of a specified index of a list

Remember that in R, the first index of any given character is 1. For example, the “H” in “Hello” has the index value 1, the second character “e” has index value 2, and so on.

Now, to add an item to the list in R, we use the append() function. To add an item to the right of a specified index in a code, we add after = index number inside the append function.

Syntax

append(list, item, after = index number)Syntax for the append() function

Example

# creating a string and numerical listsmylist <- list("cherry", 'banana', 'apple')# implementing the append() functionappend(mylist, "orange", after = 2)Run

Explanation

In the code above we create a list mylist, and add the item "orange" to the list right after the second item, “banana”.

Relevant Answers

Explore Courses

Free Resources

License: Creative Commons-Attribution-ShareAlike 4.0 (CC-BY-SA 4.0)

Tag » Add Element List R