How to get the Index of Specified Element in a List in R - Step by Step Examples

How to get the Index of Specified Element in a List in R ?

To find the index of a specified element in a list in R, you can use the which function.

In this example,

We create a vector named my_list with some elements.
We use the which function to find the index of a specific element. The function returns the positions of elements that are TRUE for the given condition.
The which function returns the index of the first occurrence of the element in the list, or an integer(0) if the element is not found.
Finally, we print the index to standard output.

my_list <- c(10, 20, 30, 40, 50)
index <- which(my_list == 40)
cat('Index of element is:', index)

Index of element is: 4

In this example,

We create a vector named my_list with some string elements.
We use the which function to find the index of a specific string. The function returns the positions of elements that are TRUE for the given condition.
The which function returns the index of the first occurrence of the string in the list, or an integer(0) if the string is not found.
Finally, we print the index to standard output.

my_list <- c('apple', 'banana', 'cherry', 'date', 'elderberry')
index <- which(my_list == 'cherry')
cat('Index of element is:', index)

Index of element is: 3

In this tutorial, we learned How to get the Index of Specified Element in a List in R language with well detailed examples.