Preferred method of checking object's class in R

Question

What is the preferred method of checking an object's class in R? (1) ``` is.data.frame(df) ``` (2) ``` class(df) == 'data.frame' ``` (3) ``` 'data.frame' %in% class(df) ```

Accepted Answer

I would say

```
inherits(df,"data.frame")
```

or

```
is(df,"data.frame")
```

among other things, #2 in your list can fail because (as you suggest in #3) `class(df)` can have length > 1. (`is.data.frame` is nice, but not all classes have `is.` methods: see `methods("is")`)

Preferred method of checking object's class in R

Solution

Problem