R functions allow to manipulate arrays, lists, data frames and slices of data from matrices in a repetitive way, without using loops

This statement highlights the functional programming capabilities of R, which allows for efficient data manipulation. R provides various functions that enable you to perform operations on data structures like arrays, lists, data frames, and matrices without the need for explicit loops. Some common functions that exemplify this concept include:

1. lapply(): Applies a function to each element of a list and returns a list.
2. sapply(): Similar to lapply(), but it simplifies the output to a vector or matrix if possible.
3. apply(): Applies a function to the rows or columns of a matrix or data frame.
4. tapply(): Applies a function over subsets of a vector and is useful for grouped calculations.
5. mapply(): A multivariate version of sapply() that allows for multiple arguments.

These functions help in enhancing code efficiency and readability while reducing the need for traditional loops, making R a powerful language for data analysis and manipulation.