您可以在 browser()中使用参数 expr :

fun <- function(x, y, n) {
  result <- 0
  for (i in 1:n) {
    browser(expr = {i == 5})
    result <- result + i * ( x + y)
  }
  return(result)
}

如果表达式的计算结果为 TRUE ，则它将仅打开调用 browser()的环境.

It will then only open the environment where browser() was called from if the expression evaluates to TRUE.

如果要使用 debug():

debug(fun, condition = i == 5)

然后调用该函数:

fun <- function(x, y, n) {
  result <- 0
  for (i in 1:n) {
    result <- result + i * ( x + y)
  }
  return(result)
}

fun(x, y, n)