all: Are All Values True?
In robertzk/monadicbase: The R Base Package

Description Usage Arguments Details Value S4 methods Note References See Also Examples

Given a set of logical vectors, are all of the values true?

1	all(..., na.rm = FALSE)

`...`	zero or more logical vectors. Other objects of zero length are ignored, and the rest are coerced to logical ignoring any class.
`na.rm`	logical. If true `NA` values are removed before the result is computed.

This is a generic function: methods can be defined for it directly or via the Summary group generic. For this to work properly, the arguments ... should be unnamed, and dispatch is on the first argument.

Coercion of types other than integer (raw, double, complex, character, list) gives a warning as this is often unintentional.

This is a primitive function.

The value is a logical vector of length one.

Let x denote the concatenation of all the logical vectors in ... (after coercion), after removing NAs if requested by na.rm = TRUE.

The value returned is TRUE if all of the values in x are TRUE (including if there are no values), and FALSE if at least one of the values in x is FALSE. Otherwise the value is NA (which can only occur if na.rm = FALSE and ... contains no FALSE values and at least one NA value).

This is part of the S4 Summary group generic. Methods for it must use the signature x, ..., na.rm.

That all(logical(0)) is true is a useful convention: it ensures that

1	all(all(x), all(y)) == all(x, y)

even if x has length zero.

Becker, R. A., Chambers, J. M. and Wilks, A. R. (1988) The New S Language. Wadsworth & Brooks/Cole.

any, the ‘complement’ of all, and stopifnot(*) which is an all(*) ‘insurance’.

range(x <- sort(round(stats::rnorm(10) - 1.2, 1)))
if(all(x < 0)) cat("all x values are negative\n")

all(logical(0))  # true, as all zero of the elements are true.