Check Least Number of Arguments a Function Expects in R

To find the least number of arguments a function expects while using in R can be done with the help of the syntax: length(formals(“function_name”)). For example, to find the number of arguments expected by mutate function of dplyr package can be calculated by using the command length(formals(mutate)) but we need to make sure that the package is loaded.

Examples

 Live Demo

library(ggplot2)
length(formals(ggplot))

Output

[1] 4
length(formals(boxplot))
[1] 2
length(formals(qnorm))
[1] 5
length(formals(rnorm))
[1] 3
length(formals(rpois))
[1] 2
length(formals(runif))
[1] 3
length(formals(punif))
[1] 5
length(formals(plot))
[1] 3
length(formals(pbinom))
[1] 5
length(formals(qbinom))
[1] 5
length(formals(hist))
[1] 2
length(formals(data))
[1] 7
length(formals(matrix))
[1] 5
length(formals(list))
[1] 0
length(formals(data.frame))
[1] 6
length(formals(paste))
[1] 4
length(formals(gsub))
[1] 7
length(formals(factor))
[1] 6
length(formals(cut))
[1] 2
length(formals(t.test))
[1] 2
length(formals(lm))
[1] 14
length(formals(glm))
[1] 18
length(formals(prop.test))
[1] 6
length(formals(pairwise.t.test))
[1] 7
length(formals(aov))
[1] 6
length(formals(dunif))
[1] 4
length(formals(dpois))
[1] 3
length(formals(dnorm))
[1] 4
length(formals(cbind))
[1] 2
length(formals(rbind))
[1] 2
length(formals(cor))
[1] 4
length(formals(cor.test))
[1] 2
length(formals(mean))
[1] 2
length(formals(sum))
[1] 0
length(formals(median))
[1] 3
length(formals(quantile))
[1] 2
length(formals(rank))
[1] 3
length(formals(var))
[1] 4
length(formals(sd))
[1] 2
length(formals(round))
[1] 0