2.7 列表

x <- list(a = 1, b = 2, c = list(d = c(1, 2, 3), e = "hello"))
print(x)

## $a
## [1] 1
## 
## $b
## [1] 2
## 
## $c
## $c$d
## [1] 1 2 3
## 
## $c$e
## [1] "hello"

base::print.simple.list(x)

##      _    
## a    1    
## b    2    
## c.d1 1    
## c.d2 2    
## c.d3 3    
## c.e  hello