R: The Number of Levels of a Factor

nlevels {base} | R Documentation

## The Number of Levels of a Factor

### Description

Return the number of levels which its argument has.

### Usage

    nlevels(x)

### Arguments

`x` | an object, usually a factor.

### Details

This is usually applied to a factor, but other objects can have levels.

The actual factor levels (if they exist) can be obtained with the `levels` function.

### Value

The length of `levels(x)`, which is zero if `x` has no levels.

### See Also

`levels`, `factor`.

### Examples

    nlevels(gl(3, 7)) # = 3

[Package base version 3.1.2 Index]