sprintf似乎忽略了一些特殊字符

Question

这是一个错误吗？

> nchar(sprintf("%-20s", "Sao Paulo"))
[1] 20
> nchar(sprintf("%-20s", "São Paulo"))
[1] 19

---

> sessionInfo()
R version 3.2.4 (2016-03-10)
Platform: x86_64-apple-darwin13.4.0 (64-bit)
Running under: OS X 10.11.4 (El Capitan)

locale:
[1] en_GB.UTF-8/en_GB.UTF-8/en_GB.UTF-8/C/en_GB.UTF-8/en_GB.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

loaded via a namespace (and not attached):
[1] tools_3.2.4    fortunes_1.5-2

Answer 1

如果您阅读 sprintf 的帮助页面，它会谈到编码很重要这一事实。\n如果您查看 nchar 的帮助页面，您还会了解到有不同的类型。

\n\n

结果，我看到以下内容（在 Linux，R 3.3.0 beta 上）：

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> nchars <- function(x) vapply(c("bytes","chars","width"),\n                               function(typ) nchar(x, type=typ), 1)\n> sp <- "S\xc3\xa3o Paulo"\n> Encoding(sp)\n[1] "UTF-8"\n> nchars(sp)\nbytes chars width \n   10     9     9 \n> nchars(sprintf("%-20s", sp))\nbytes chars width \n   20    19    19 \n> \n

\n\n

所以我声称根本没有错误。\n我所说的并不比@TheRimalaya多，但我得出了不同的结论

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