16 setembro, 2021
Selo DC
Revisando
Realidade
Código e inspeção
# Criamos tres objetos tipo 'character'
x <- c("a", "b", "d")
y <- c("a", "abc", "e")
z <- c("f", "abc", "b")
# Inspecionando os objetos
.Internal(inspect(x))
## @0x0000000006f84908 16 STRSXP g0c3 [REF(1)] (len=3, tl=0)
## @0x0000000006589e38 09 CHARSXP g0c1 [MARK,REF(10),gp=0x61] [ASCII] [cached] "a"
## @0x0000000006c3d580 09 CHARSXP g0c1 [MARK,REF(14),gp=0x60] [ASCII] [cached] "b"
## @0x0000000006a5ec00 09 CHARSXP g0c1 [MARK,REF(5),gp=0x61] [ASCII] [cached] "d"
.Internal(inspect(y))
## @0x0000000006f84868 16 STRSXP g0c3 [REF(1)] (len=3, tl=0)
## @0x0000000006589e38 09 CHARSXP g0c1 [MARK,REF(10),gp=0x61] [ASCII] [cached] "a"
## @0x0000000006984360 09 CHARSXP g0c1 [REF(7),gp=0x60] [ASCII] [cached] "abc"
## @0x0000000000393188 09 CHARSXP g0c1 [MARK,REF(5),gp=0x61] [ASCII] [cached] "e"
.Internal(inspect(z))
## @0x0000000006f847c8 16 STRSXP g0c3 [REF(1)] (len=3, tl=0)
## @0x000000000641d518 09 CHARSXP g0c1 [MARK,REF(6),gp=0x61] [ASCII] [cached] "f"
## @0x0000000006984360 09 CHARSXP g0c1 [REF(7),gp=0x60] [ASCII] [cached] "abc"
## @0x0000000006c3d580 09 CHARSXP g0c1 [MARK,REF(14),gp=0x60] [ASCII] [cached] "b"
Código e inspeção
# Se alterar apenas a 'string', ocorre apenas a mudanca do # apontamento com modificacao local x[2] <- "f" .Internal(inspect(x)) ## @0x0000000006f84908 16 STRSXP g0c3 [REF(1)] (len=3, tl=0) ## @0x0000000006589e38 09 CHARSXP g0c1 [MARK,REF(10),gp=0x61] [ASCII] [cached] "a" ## @0x000000000641d518 09 CHARSXP g0c1 [MARK,REF(9),gp=0x61] [ASCII] [cached] "f" ## @0x0000000006a5ec00 09 CHARSXP g0c1 [MARK,REF(5),gp=0x61] [ASCII] [cached] "d" # Alterando os elementos, bem como sua dimensao, ocorrera a copia # do objeto STRSXP, porem os elementos continuam apontando para as suas # respectivas 'strings' globais x[4] <- "f" .Internal(inspect(x)) ##@0x0000000006988190 16 STRSXP g0c3 [REF(1)] (len=4, tl=0) ## @0x0000000006589e38 09 CHARSXP g0c1 [MARK,REF(11),gp=0x61] [ASCII] [cached] "a" ## @0x000000000641d518 09 CHARSXP g0c1 [MARK,REF(13),gp=0x61] [ASCII] [cached] "f" ## @0x0000000006a5ec00 09 CHARSXP g0c1 [MARK,REF(6),gp=0x61] [ASCII] [cached] "d" ## @0x000000000641d518 09 CHARSXP g0c1 [MARK,REF(13),gp=0x61] [ASCII] [cached] "f"
Bons estudos!
