Add or Append Element to List in R (2024)

Table of Contents

Quick Examples of Adding Elements to List R Base append() Syntax Append Element to List Insert Item to List at a certain Place Append Several Items to the List Append the List with Another List Using c() to Append List Frequently Asked Questions of Append Element to List in R Conclusion Related Articles References FAQs References

To add or append an element to the list in R use the append() function. This function takes 3 parameters input list, the string or list you wanted to append, and position.

The list.append() function from the rlist package can also append one list with another in R. In this article, I will explain how to append/add an element to a list by using the R base append() function and list.append() function from the list package with multiple examples.

Related: You can also add an element to the list using a loop in r.

Quick Examples of Adding Elements to List

Following are quick examples of adding or appending elements to the list in R.

# Quick examples of appending element to list# Example 1: Using R base append()li = list('java','python')li2 <- append(li,'r')print(li2)# Example 2: Add element to list at specified positionli = list('java','python')li2 <- append(li,'r',after=1)print(li2)# Example 3: Using list.append()library('rlist')li2 <- list.append(li,'r')print(li2)# Example 4: Named Listlibrary('rlist')li = list(id=11,name='python')li2 <- list.append(li,pages=34)print(li2)# Example 5: Append list with another listli = list('java','python')li2 = list('r','php')li3 <- append(li,li2)print(li3)

R Base append() Syntax

Following is the syntax of the R base append() function

# Syntax of append()append(x, values, after = length(x))

Parameters

x: The list that will receive the new elements.
values: Items to add, which can be a string, a list, or a vector.
after: The index at which to insert the new elements. This is optional; if not specified, the elements will be added at the end of the list.

Append Element to List

You can use the append() function to add an item to a list. If you do not specify the position(in which we want to specify the position of an element), the new item is added to the end of the list by default. The following example adds an element r to the list.

# Add element to listli = list('java','python')print(li)li2 <- append(li,'r')print(li2)

Yields below output. Note that we have added the item r to the list.

Insert Item to List at a certain Place

You can use the after parameter to determine where to insert an item in a list. In the example below, an item is added after the first position.

# Add element to list at specified positionli = list('java','python')li2 <- append(li,'r',after=1)print(li2)

Yields below output.

Append Several Items to the List

Package rlist provides a list.append() Function to insert several items into the list at once. To use this function first, you need toinstall R packageby usinginstall.packages("rlist")and load it using thelibrary("rlist").

# Add multiple elements to listlibrary('rlist')li2 <- list.append(li,'r','50')print(li2)

Yields below output.

# Output[[1]][1] "java"[[2]][1] "python"[[3]][1] "r"[[4]][1] "50"

Using this function we can also append elements to the named list.

# Named Listlibrary('rlist')li = list(id=11,name='python')li2 <- list.append(li,pages=34)print(li2)

Append the List with Another List

To append one list with another list pass both lists to the append() function, this adds a second list at the end of the first list and produces a combined list.

# Append list with another listli = list('java','python')li2 = list('r','php')li3 <- append(li,li2)print(li3)# Output:# [[1]]# [1] "java"# [[2]]# [1] "python"# [[3]]# [1] "r"# [[4]]# [1] "php"

Using c() to Append List

If you are unaware that c() is a combined function used to merge the list, vector, etc. The following example uses c() to append two lists.

# using c()li3 = c(li,li2)print(li3)

Yields the same as the above output.

Frequently Asked Questions of Append Element to List in R

How do I append an element to a list in R?

You can use the c() function to concatenate or append elements to a list. For example, append_list <- c(my_list1, new_element)

How can I append multiple elements at once?

rlist package provides a list.append() function to append multiple elements to the list in R. For example, library('rlist')
my_list <- list.append(my_list1,'new_element1','new_element2')

How do you insert an element at a specific position in the list?

Using the R base append() function with the after parameter to insert an element at a specific position. For example, my_list <- append(my_list1, new_element, after = 2)

How can I append another list to an existing list?

To append a list to an existing list you can use the R base function. It appends the new list at the end of the existing list. For example, my_list <- append(my_list1, my_list2)

Conclusion

In this article, you have learned how to add or append an element to the list by using R base append(), the list.append() from the rlist package. You can view the full example from this article at Github R Programming Examples Project.

You can view the full example from this article in the R Programming Examples Project on GitHub.

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References

https://www.rdocumentation.org/packages/base/versions/3.6.2/topics/append

FAQs

Add or Append Element to List in R? ›

To add or append an element to the list in R use the append() function. This function takes 3 parameters input list, the string or list you wanted to append, and position. The list. append() function from the rlist package can also append one list with another in R.

Keep Reading ›

How do you append an element to a list in R? ›

Here are five different methods to add elements to an existing list:

Using the $ operator. You can use the $ operator to add new elements to a list or modify existing ones. ...
Using the c() function. ...
Using the append() function. ...
Using the `rlist` library. ...
Adding Multiple Elements.

Sep 14, 2023

Read On ›

What is the difference between add and append in list? ›

List<T> in C# only has the void Add(T item) method to add a single item to the list by modifying the instance. IEnumerable<T> Append(this IEnumerable<T> source, T element) on the other hand is an extension method defined on the IEnumerable<T> interface (which is implemented by all lists).

Read On ›

How do you add elements to a list in R loop? ›

You can use a for loop to add elements to a list in R, first create an empty list using the list() function. Then, use the for loop to add a specified range of numbers to the empty list. During each iteration of the loop, an element will be added to the empty list until the loop ends.

How do you add to a list using append? ›

So, . append() adds a list inside of a list. Lists are objects, and when you use . append() to add another list into a list, the new items will be added as a single object (item).

Explore More ›

How to append to c() in R? ›

A: To append an item to a list using the c() function, you can combine the list with the new item. For example, my_list <- c(my_list, new_item) adds new_item to the end of my_list .

Learn More ›

How do you combine elements of a list in R? ›

Combine list elements into a single data structure

list_c() combines elements into a vector by concatenating them together with vctrs::vec_c() .
list_rbind() combines elements into a data frame by row-binding them together with vctrs::vec_rbind() .

More items...

How do you append elements of a list to another list? ›

In general, appending a list to another list means that you have a list item as one of your elements of your list. For example: a = [1,2] a. append([3,4]) print(a) # [1,2,[3,4]] In your example, a is appended to itself, so now a is an element within itself.

Tell Me More ›

What happens if you append a list to a list? ›

NOTE: A list is an object. If you append another list onto a list, the parameter list will be a single object at the end of the list.

Tell Me More ›

Does append mean add? ›

To append means to add on, usually to the end of something. You might want to append a clause onto a contract if you feel something has been left unsaid in it.

Discover More ›

How do you add elements to a list in a loop? ›

How To Add Values Into An Empty List From A For Loop?

Using Append() Method.
Using List Comprehension.
Using extend() Method.
Using the + Operator.

Feb 15, 2024

Learn More ›

How to fill a list in R? ›

To create a simple R list, you can use the list() function using the elements to be added to your list. In this code example, a list of four values has been created. As you can see, these values don't have an identical data type and can still be grouped within a list. You can also create a list of named items in R.

How do you add elements from a list to a string? ›

To convert a list to a string, use Python List Comprehension and the join() function. The list comprehension will traverse the elements one by one, and the join() method will concatenate the list's elements into a new string and return it as output.

How to append elements to a list in R? ›

What does append to a list mean? ›

In Python, the append() function is a built-in function used to add an item to the end of a list. The append() method is a member of the list object, and it is used to modify the contents of an existing list by adding a new element to the end of the list. The append function returns nothing.

Read The Full Story ›

What is the difference between append and extend list? ›

Append function in Python adds a single element to the end of the list, whereas the extend function adds multiple elements (from an iterable) to the list. Append takes a single element as an argument, while extend takes an iterable as an argument.

Tell Me More ›

How do I concatenate items in a list in R? ›

To join or concatenate two different lists in R, we use the c() function. The c() function combines the elements of a list by considering the lists as its parameter values.

Learn More Now ›

How do you append an element to an array? ›

How to append an element in an array in JavaScript?

Using JavaScript push() Method.
Using JavaScript unshift() Method.
Using JavaScript splice() Method.
Using JavaScript concat() Method.
Javascript spread operator.
Using Lodash _.concat() function.
Using the array length property.
Using Array.map() Method.

Aug 13, 2024

How do you append data in Rstudio? ›

To append (add) rows from one or more dataframes to another, use the bind_rows() function from dplyr . This function is especially useful in combining survey responses from different individuals. bind_rows() will match columns by name, so the dataframes can have different numbers and names of columns and rows.

Learn More ›

How do you paste elements of a list together in R? ›

How to use the paste() function in R? A simple paste() will take multiple elements as inputs and concatenate those inputs into a single string. The elements will be separated by a space as the default option. But you can also change the separator value using the 'sep' parameter.