在ifelse中使用Reduce/do.call

x <- 1:10
y <- ifelse(x > 5, "大于5", "小于等于5")
print(y)

x <- c(1, 2, 3, 4)
y <- Reduce("+", x)
print(y)

x <- c(1, 2, 3, 4)
y <- do.call("sum", list(x))
print(y)

x <- 1:10
y <- ifelse(x > 5, "大于5", ifelse(x > 3, "大于3小于等于5", "小于等于3"))
print(y)

x <- 1:10
conditions <- c(x > 5, x > 3, x > 1)
results <- c("大于5", "大于3小于等于5", "大于1小于等于3", "小于等于1")
y <- Reduce(function(x, condition, result) {
  ifelse(condition, result, x)
}, init=results[1], x=x, condition=conditions, result=results[-1])
print(y)