| isS4 {base} | R Documentation |
Tests whether the object was created from a formally defined class.
isS4(object) asS4(object, value = TRUE)
object |
Any R object. |
value |
A single logical value; not NA. |
Note that isS4 does not rely on the methods
package, so in particular it can be used to detect the need to
require() that package. (But asS4 does depend on
methods.)
You should not set the flag directly unless you really know why. In
the future, S4 methods may be restricted to S4 objects for primitive
functions; then asS4 would allow method dispatch of S4 methods
for S3 classes.
For all other purposes, an object will satisfy isS4(x) if and
only if it should.
isS4 always returns TRUE or FALSE according to
whether the internal flag marking an S4 object has been turned on for
this object.
asS4 will turn this flag on or off. But see the details.
isS4(pi) # FALSE
isS4(getClass("MethodDefinition")) # TRUE