CODEWITHSUNDEEP
r
Apostolos
Apostolos

Reputation: 598

Refer to list element name via a variable

I would like to ask if there is a way to refer to a list element name via a variable:

Labels <- vector(mode = "list") # Make a list called "Labels"
Labels[[1]] <- c(1,3,5,7) # Assign value to the first list element
names(Labels)[1] <- "Name" # Assign the name "Name" to the first list element
print(Labels)
print(Labels$Name)
# [1] 1 3 5 7

# Now I have the name of the first list element "Name"
# in the variable "ElementName"
ElementName <- "Name"

# How R will understand in the next line
# that I refer to the value "Name" of the variable "ElementName"
# in order to get 
# [1] 1 3 5 7

print(Labels$ElementName)

Upvotes: 3

Views: 2365

Answers (1)

akrun
akrun

Reputation: 886998

We can use [[ to extract the list elements.

Labels[[ElementName]]
#[1] 1 3 5 7

If we are using the name of the list element, we use quotes

Labels[['Name']]
#[1] 1 3 5 7

For more info, check ?"[[" or ?Extract

Upvotes: 4

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