R: Check the class membership of an argument

checkClass {checkmate} | R Documentation

## Check the class membership of an argument

### Description

Check the class membership of an argument

### Usage

    checkClass(x, classes, ordered = FALSE, null.ok = FALSE)

    check_class(x, classes, ordered = FALSE, null.ok = FALSE)

    assertClass(
      x,
      classes,
      ordered = FALSE,
      null.ok = FALSE,
      .var.name = vname(x),
      add = NULL
    )

    assert_class(
      x,
      classes,
      ordered = FALSE,
      null.ok = FALSE,
      .var.name = vname(x),
      add = NULL
    )

    testClass(x, classes, ordered = FALSE, null.ok = FALSE)

    test_class(x, classes, ordered = FALSE, null.ok = FALSE)

    expect_class(
      x,
      classes,
      ordered = FALSE,
      null.ok = FALSE,
      info = NULL,
      label = vname(x)
    )

### Arguments

`x` | [any] Object to check.
`classes` | [`character`] Class names to check for inheritance with `inherits`. `x` must inherit from all specified classes.
`ordered` | [`logical(1)`] Expect `x` to be specialized in provided order. Default is `FALSE`.
`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 `assertClass`/`assert_class` return `x` invisibly, whereas `checkClass`/`check_class` and `testClass`/`test_class` return `TRUE`. If the check is not successful, `assertClass`/`assert_class` throws an error message, `testClass`/`test_class` returns `FALSE`, and `checkClass` returns a string with the error message. The function `expect_class` always returns an `expectation`.

### See Also

Other attributes: `checkMultiClass()`, `checkNamed()`, `checkNames()`

Other classes: `checkMultiClass()`, `checkR6()`

### Examples

    # Create an object with classes "foo" and "bar"
    x = 1
    class(x) = c("foo", "bar")

    # is x of class "foo"?
    testClass(x, "foo")

    # is x of class "foo" and "bar"?
    testClass(x, c("foo", "bar"))

    # is x of class "foo" or "bar"?
    ## Not run:
    assert(
      checkClass(x, "foo"),
      checkClass(x, "bar")
    )

    ## End(Not run)
    # is x most specialized as "bar"?
    testClass(x, "bar", ordered = TRUE)

[Package checkmate version 2.0.0 Index]