用来测试参数是否作为R函数中的输入存在的`hasArg`和` exists `有什么不同

my_function <- function(x) {
  if (hasArg(x)) {
    print("Parameter x exists.")
  } else {
    print("Parameter x does not exist.")
  }
}

my_function(x = 10)  # Output: "Parameter x exists."
my_function(y = 20)  # Output: "Parameter x does not exist."

x <- 10

if (exists("x")) {
  print("Object x exists.")
} else {
  print("Object x does not exist.")
}

if (exists("y")) {
  print("Object y exists.")
} else {
  print("Object y does not exist.")
}