2.3.1 Summary - JulTob/R GitHub Wiki

This will give you a quick overview of the contents of a variable:

summary(my_var)

Example

# Build factor_survey_vector with clean levels
survey_vector <- c("M", "F", "F", "M", "M")
factor_survey_vector <- factor(survey_vector)
levels(factor_survey_vector) <- c("Female", "Male")
factor_survey_vector

# Generate summary for survey_vector
summary(survey_vector)

# Generate summary for factor_survey_vector
summary(factor_survey_vector)

[1] Male   Female Female Male   Male  
Levels: Female Male
# Generate summary for survey_vector
summary(survey_vector)
   Length     Class      Mode 
        5 character character 
# Generate summary for factor_survey_vector
summary(factor_survey_vector)
Female   Male 
     2      3 

Have a look at the output. The fact that you identified "Male" and "Female" as factor levels in factor_survey_vector enables R to show the number of elements for each category.