R: Get Class Definition

getClass {methods} | R Documentation

## Get Class Definition

### Description

Get the definition of a class.

### Usage

    getClass(Class, .Force = FALSE)
    getClassDef(Class, where=-1)

### Arguments

`Class` | the character-string name of the class.
`.Force` | if `TRUE`, return `NULL` if the class is undefined; otherwise, an undefined class results in an error.
`where` |

{ where to search for the definition; by default, anywhere on the current search list.}

### Details

A call to `getClass` returns the complete definition of the class supplied as a string, including all slots, etc. in classes that this class extends. A call to `getClassDef` returns the definition of the class from that database, unadorned. It's usually `getClass` you want.

The statement that `getClass` fails if the class is undefined is not quite true at the moment. A few special vector types and informally defined classes are allowed, and `getClass` returns `NULL` for these. But don't count on it; eventually these holes in the class system should be plugged.

In any case, if you really want to know whether a class is formally defined, call `isClass`.

### Value

The object defining the class. This is an object of class `"classRepEnvironment"`. However, do not deal with the contents of the object directly unless you are very sure you know what you're doing. Even then, it is nearly always better practice to use functions such as `setClass` and `setIs`. Messing up a class object will cause great confusion.

### Author(s)

John Chambers

### References

The web page http://www.omegahat.org/RSMethods/index.html is the primary documentation.

The functions in this package emulate the facility for classes and methods described in Programming with Data, (John M. Chambers, Springer, 1998). See this book for further details and examples.

### See Also

Classes, `setClass`, `isClass`.

### Examples

    getClass("numeric") ## a built in class

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