Lists

AList <- list(1:5,
              letters[1:6],
              c(TRUE,FALSE,FALSE,TRUE))
AList
[[1]]
[1] 1 2 3 4 5

[[2]]
[1] "a" "b" "c" "d" "e" "f"

[[3]]
[1]  TRUE FALSE FALSE  TRUE
AList[1:2]
[[1]]
[1] 1 2 3 4 5

[[2]]
[1] "a" "b" "c" "d" "e" "f"
AList[1]
[[1]]
[1] 1 2 3 4 5
AList[[2]]
[1] "a" "b" "c" "d" "e" "f"
AList[[1:2]]
[1] 2
AList[[1:3]]
Error in AList[[1:3]]:
recursive indexing failed at level 2
Traceback:
length(AList)
[1] 3
FDR <- list(c("John","Delano"),
            c("Roosevelt"))
names(FDR) <- c("first.name","last.name")
FDR
$first.name
[1] "John"   "Delano"

$last.name
[1] "Roosevelt"
FDR <- list(first.name=c("John","Delano"),
            last.name=c("Roosevelt"))
FDR
$first.name
[1] "John"   "Delano"

$last.name
[1] "Roosevelt"
FDR$last.name
[1] "Roosevelt"
FDR[["last.name"]]
[1] "Roosevelt"
UK <- list(
    country.name = c("England","Northern Ireland","Scotland",
                                                  "Wales"),
    population   = c(54786300,1851600,5373000,3099100),
    area.sq.km   = c(130279,13562,77933,20735),
    GVA.cap      = c(26159,18584,23685,18002))
UK
$country.name
[1] "England"          "Northern Ireland" "Scotland"         "Wales"           

$population
[1] 54786300  1851600  5373000  3099100

$area.sq.km
[1] 130279  13562  77933  20735

$GVA.cap
[1] 26159 18584 23685 18002
data.frame(UK)
      country.name population area.sq.km GVA.cap
1          England   54786300     130279   26159
2 Northern Ireland    1851600      13562   18584
3         Scotland    5373000      77933   23685
4            Wales    3099100      20735   18002