How to add Key Value Pair to List in R ? (original) (raw)

Last Updated : 23 Jul, 2025

A key-value pair can be explained as a set of two linked data items where a key uniquely identifies a value or a set of values in the data. Since a list can hold multiple data-types data, we can have a key-value pair stored in the list

Method 1:

We can assign variables to each key and value. Store each key-value pair after building the list using square brackets.

R `

rm(list = ls())

create key value variables

key1 <- "Age" value1 <- 21

key2 <- "Name" value2 <- "Pulkit"

create the list

mylist <- list()

Build up key value pairs

mylist[[ key1 ]] <- value1 mylist[[ key2 ]] <- value2

Access value using the key

print(mylist$Age) print(mylist$Name)

Output:

21 Pulkit

Method 2:

Another way of doing this without using any additional variables is to specify the key and the value in the list() function while creating the list.

Example

R `

rm(list = ls())

Creating the list

mylist<-list("Name"="Pulkit","Age"=21, "Gender"="Male")

Access value using the key

print(mylist$Age) print(mylist$Gender)

Output:

21 Male

Method 3: Using setNames()

Another approach we can take to add a key-value pair in the list is to setNames() function and inside it, we use as.list(). Basically what we will have here is a syntax like given below, which will create a list and assign all the keys with their respective values.

Syntax:

variable<-setNames(as.list(values), keys)

Example:

R `

rm(list = ls())

initialize keys and respected values

students <- c("Pulkit", "Ritika", "Parth", "Vishesh", "Dharvik", "krishav", "Reshav")

marks <- c(75, 92, 97, 80, 85, 87, 52)

make the list

results <- setNames(as.list(marks), students)

Access value using the key

print(results$Pulkit)

Output: