How to plot a graph for the output of table() in R for Categorical variables against their occurring frequencies?

Question

library(gapminder)
a <- table(gapminder$continent)
a
#  Africa Americas     Asia   Europe  Oceania 
#     624      300      396      360       24

How do I plot a histogram in R for the below table where categorical should be in the X-axis and frequencies should be on the y-axis?

Answer 1

There is a plot method for a table so you can simply do the following:

library(gapminder)
a <- table(gapminder$continent)
plot(a)

Or you could plot it as a barplot:

barplot(a)

Answer 2

Wrap a in as.data.frame and then plot.

library(ggplot2)
library(gapminder)
a <- as.data.frame(table(gapminder$continent))
ggplot(a, aes(Var1, Freq)) + geom_col()