小编Wol*_*olf的帖子

注意：此问题/答案是从Julia Slack频道复制的。

如果我有一个任意的Julia Array，该如何添加另一个维度。

julia> a = [1, 2, 3, 4]
4-element Array{Int64,1}:
 1
 2
 3
 4

所需的输出将是例如：

julia> a[some_magic, :]
1×4 Array{Int64,2}:
 1  2  3  4

要么：

julia> a[:, some_magic]
4×1 Array{Int64,2}:
 1
 2
 3
 4

注意：这个问题是由这个话语线索引起的。

考虑以下示例字符串：

str = "This is some text that initially consists of normal ASCII characters—but oh wait, the em-dash is only part of the extended ASCII character set!"

尝试使用其长度遍历此字符串：

for i in 1:length(str)
  println(i, str[i])
end

失败StringIndexError，返回循环中途返回以下消息：

ERROR: StringIndexError("This is some text that initially consists of normal ASCII characters—but oh wait, the em-dash is only part of the extended ASCII character set!", 70)
Stacktrace:
 [1] string_index_err(::String, ::Int64) at ./strings/string.jl:12
 [2] getindex_continued(::String, ::Int64, ::UInt32) at ./strings/string.jl:217 …