Get the Number of Levels of a Factor in R Programming – nlevels() Function

nlevels() function in R Language is used to get the number of levels of a factor.

Syntax: nlevels(x)

Parameters:
x: Factor Object

Example 1:

# R program to get the number
# of levels of a factor

# Creating a factor
x <- gl(3, 2)
x

# Calling nlevels() function
# to get the number of levels
nlevels(x)

Output:

[1] 1 1 2 2 3 3
Levels: 1 2 3
[1] 3

Example 2:

# R program to get the number
# of levels of a factor

# Creating a factor
gender <- factor(c("female", "male", "male", "female"));
gender

# Calling nlevels() function
# to get the number of levels
nlevels(gender)

Output:

[1] female male   male   female
Levels: female male
[1] 2