R: Check if an argument is a single missing value

checkScalarNA {checkmate} | R Documentation

## Check if an argument is a single missing value

### Description

Check if an argument is a single missing value

### Usage

    checkScalarNA(x, null.ok = FALSE)

    check_scalar_na(x, null.ok = FALSE)

    assertScalarNA(x, null.ok = FALSE, .var.name = vname(x), add = NULL)

    assert_scalar_na(x, null.ok = FALSE, .var.name = vname(x), add = NULL)

    testScalarNA(x, null.ok = FALSE)

    test_scalar_na(x, null.ok = FALSE)

    expect_scalar_na(x, null.ok = FALSE, info = NULL, label = vname(x))

### Arguments

`x` | [any] Object to check.
`null.ok` | [`logical(1)`] If set to `TRUE`, `x` may also be `NULL`. In this case only a type check of `x` is performed, all additional checks are disabled.
`.var.name` | [`character(1)`] Name of the checked object to print in assertions. Defaults to the heuristic implemented in `vname`.
`add` | [`AssertCollection`] Collection to store assertion messages. See `AssertCollection`.
`info` | [character(1)] Extra information to be included in the message for the testthat reporter. See `expect_that`.
`label` | [`character(1)`] Name of the checked object to print in messages. Defaults to the heuristic implemented in `vname`.

### Value

Depending on the function prefix: If the check is successful, the functions `assertScalarNA`/`assert_scalar_na` return `x` invisibly, whereas `checkScalarNA`/`check_scalar_na` and `testScalarNA`/`test_scalar_na` return `TRUE`. If the check is not successful, `assertScalarNA`/`assert_scalar_na` throws an error message, `testScalarNA`/`test_scalar_na` returns `FALSE`, and `checkScalarNA` returns a string with the error message. The function `expect_scalar_na` always returns an `expectation`.

### See Also

Other scalars: `checkCount`, `checkFlag`, `checkInt`, `checkNumber`, `checkScalar`, `checkString`

### Examples

    testScalarNA(1)
    testScalarNA(NA_real_)
    testScalarNA(rep(NA, 2))

[Package checkmate version 1.8.2 Index]