如何使用get()调用R中function中的变量？

Question

I am trying to use get() in a function. Sometimes it works and sometimes it doesn't. The data is:

ID<-c("001","002","003","004","005","006","007","008","009","010","NA","012","013")
Name<-c("Damon Bell","Royce Sellers",NA,"Cali Wall","Alan Marshall","Amari Santos","Evelyn Frye","Kierra Osborne","Mohammed Jenkins","Kara Beltran","Davon Harmon","Kaitlin Hammond","Jovany Newman")
Sex<-c("Male","Male","Male",NA,"Male","Male",NA,"Female","Male","Female","Male","Female","Male")
Age<-c(33,27,29,26,27,35,29,32,NA,25,34,29,26)
data<-data.frame(ID,Name,Sex,Age)

It works in some codes like this:

FctPieChart <- function(data,Var){
  
  dVar <- data %>%
    filter(!is.na(get(Var))) %>%
    group_by(get(Var)) %>% #changes the name of the column to "`get(Var)`"
    summarise(Count = n()) %>%
    mutate(Total = sum(Count), Percentage = round((Count/Total),3))
}  
FctPieChart(data,"Sex")

And it doesn't work in some other codes like this:

FctPieChart <- function(data,var){
  x <- data %>% 
    select(get(var))
  x
  
}  
FctPieChart(data,"Sex")

It says:

<error/simpleError>
object 'Sex' not found

Does anyone know why?

Thank you very much in advance!

Best regards,

Stephanie

Answer 1

With dplyr::select() you don't need to use get() . Instead just use select(var)

> FctPieChart <- function(data,var){
   x <- data %>% 
     select(var)
   x
 }  
> FctPieChart(data,"Sex")
      Sex
1    Male
2    Male
3    Male
4    <NA>
5    Male
6    Male
7    <NA>
8  Female
9    Male
10 Female
11   Male
12 Female
13   Male