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When I use lapply and print to the console it prints unwanted [[i]]NULL though I want the intended message to print to the console. I've tried suppressWarnings and suppressMessages but these do not remove the unwanted offender. I searched lapply and don't see an argument to silence it. This is more aesthetic as it doesn't interfere with the function. I'm not opposed to allternative printing to the console so long as the user can turn it off if they wish.

Here's an example function, the output and what I'd like to get:

Sample function:

FUN <- function(x) {
    FUN2 <- function(z) message(z)
    lapply(1:3, function(i) FUN2(paste(x, i)))
}

FUN("hello")

Output:

hello 1
hello 2
hello 3
[[1]]
NULL

[[2]]
NULL

[[3]]
NULL

Desired Output:

hello 1
hello 2
hello 3
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1 Answer

Use invisible, eg:

invisible(FUN("hello"))
hello 1
hello 2
hello 3

You can wrap it around the lapply call in the function too to make it tidier.


与恶龙缠斗过久,自身亦成为恶龙;凝视深渊过久,深渊将回以凝视…
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