vapply
vapply is a function in the R programming language, part of the `utils` package, designed to apply a function over a list or vector and return a list of the same length. It is a more constrained and often safer alternative to the generic `lapply` function. The primary distinguishing feature of `vapply` is its requirement to specify the expected output type and dimensions for each element of the returned list. This explicit specification helps catch errors early by ensuring that the function applied to each element produces a result consistent with the declared format.
The syntax for `vapply` is `vapply(X, FUN, FUN.VALUE, ..., USE.NAMES = TRUE)`. `X` is the input list or
By enforcing the `FUN.VALUE`, `vapply` can prevent unexpected behavior that might arise from `lapply` when the