To append two lists into a single list or combine multiple lists in R, you can use either the combine function c() or append() function. In this article, I will explain examples of using these two methods to combine multiple lists in R.
Let’s create the two lists to use, I will define them as list1 and list2.
# Create two lists
list1 = list('sai','ram','deepika','sahithi')
list2 = list('kumar','scott','Don','Lin')
1. R Combine Two Lists using c()
By using combine function c() you can append two lists into a single list in R. This function takes two lists as an argument and returns the combined list. The following example combines the elements from list1 and list2 objects into a single list list3.
Here c() is a combined function from the base package that can be used to combine lists, vectors, and other objects. These base functions are default available with the R installation and automatically loaded to the program.
# Using c()
list3 <- c(list1,list2)
print(list3)
Yields below output.
2. Combine Two Lists using append()
Alternatively, you can also use append() to get two lists into a single list in R. This function also takes two lists as an argument and returns the combined list.
# Using append()
list3 <- append(list1,list2)
print(list3)
Yields the same output as above.
3. Using rlist Package
Package rlist provides a list.append() function to add multiple lists to the list. In order to use this function first, you need to install R package by using install.packages("rlist") and load it using the library("rlist").
# Using list.append()
library('rlist')
list3 <- list.append(list1,list2)
print(list3)
Yields the same output as above.
4. Combine Multiple Lists using append()
Finally by using list.append() let’s combine multiple lists into a single list in R. The below examples combine elements from list1, list2 and anotherList into a single list list3.
# combine multiple lists
library('rlist')
anotherList <- list('A','B')
list3 <- list.append(list1,list2,anotherList)
print(list3)
5. Complete Example
Following is a complete example of appending two lists.
# Create two lists
list1 = list('sai','ram','deepika','sahithi')
list2 = list('kumar','scott','Don','Lin')
# Using c()
list3 <- c(list1,list2)
print(list3)
# Using append()
list3 <- append(list1,list2)
print(list3)
# Using list.append()
library('rlist')
list3 <- list.append(list1,list2)
print(list3)
6. Conclusion
In this article, you have learned how to append two lists into a single list using the R c() combine function and append() function from R base package. And also leveraged using the append() function from rlist package.