Apply a Function over a List of elements in R Programming lapply() Function (original) (raw)

Last Updated : 15 Jul, 2025

lapply() function in R Programming Language is used to apply a function over a list of elements.

lapply() function is used with a list and performs the following operations:

lapply(List, length): Returns the length of objects present in the list, List.
lapply(List, sum): Returns the sum of elements held by objects in the list, List.
lapply(List, mean): Returns the mean of elements held by objects in the list, List.
lapply(List, cumsum): Returns the cumulative sum of elements held by objects present inside the list, List.

Syntax: lapply(list, func)

Parameters:

• list: list of elements

R - Apply a Function over a List of elements

Example 1: Basic example of lapply() Function in R programming

R `

R program to illustrate

lapply() function

Creating a matrix

A = matrix(1:9, 3, 3)

Creating another matrix

B = matrix(10:18, 3, 3)

Creating a list

myList = list(A, B)

applying lapply()

determinant = lapply(myList, det) print(determinant)

`

Output:

[[1]] [1] 0

[[2]] [1] 5.329071e-15

Example 2: Apply a Function over a List of elements in R

R `

R program to illustrate

lapply() function

Creating a matrix

A = matrix(1:9, 3, 3)

Creating another matrix

B = matrix(10:18, 3, 3)

Creating a list

myList = list(A, B)

applying lapply()

sum = lapply(myList, sum) print(sum)

`

Output:

 [, 1] [, 2] [, 3]

[1, ] 1 4 7 [2, ] 2 5 8 [3, ] 3 6 9 [1] 28 80 162 [1] 6 120 504