String
Heredocs 字符串多行书写
IO.puts "start"
IO.write """
my
string
"""
IO.puts "end"
- 单引号包裹起来的叫 字符列表或者说字符集合
- 双引号包裹起来的叫字符串
Binaries
表示语法：
<< term,... >>
#示例：
iex> b = << 1, 2, 3 >>
#<<1, 2, 3>>
iex> byte_size b
#3
iex> bit_size b
#24
双引号的String即为Binary — UTF-8的连续字节序列
示例：
#返回指定位置的字符串
at(str, offset)
iex> String.at("∂og", 0) #"∂"
iex> String.at("∂og", -1) #"g"
#将字符串首字母大写
iex> String.capitalize "école" #"École"
iex> String.capitalize "ÎÎÎÎÎ" #"Îîîîî"
#将字符串打散成字符数组（元素还是字符串）
codepoints(str)
iex> String.codepoints("José's ∂øg")
#["J", "o", "s", "é", "'", "s", " ", "∂", "ø", "g"]
#转为小写
downcase(str)
iex> String.downcase "ØRSteD"
#"ørsted"
#返回n份儿复制的字符串
duplicate(str, n)
iex> String.duplicate "Ho! ", 3
#"Ho! Ho! Ho! "
#判断字符串是否是特地的字符结尾
ends_with?(str, suffix | [ suffixes ])
iex> String.ends_with? "string", ["elix", "stri", "ring"]
#true
#返回第一字母
first(str)
iex> String.first "∂og"
"∂"
#返回最后一个字母
iex> String.last "∂og"
#"g"
#返回字母序列
graphemes(str)
iex> String.codepoints "noe\u0308l" ["n", "o", "e", " ̈", "l"]
iex> String.graphemes "noe\u0308l" ["n", "o", "ë", "l"]
#计算两个字符串的相似度
jaro_distance
iex> String.jaro_distance("jonathan", "jonathon")
#0.9166666666666666
iex> String.jaro_distance("josé", "john")
#0.6666666666666666
#计算字符串长度
iex> String.length "∂x/∂y"
#5
#计算一个字符串到另一个字符串的演变过程
myers_difference
iex> String.myers_difference("banana", "panama")
#[del: "b", ins: "p", eq: "ana", del: "n", ins: "m", eq: "a"]
#返回字符串的首部和余下部分
next_codepoint
iex> String.next_codepoint("people")
#{"p", "eople"}
#判断是否为单字符的字符串
valid?(str)
iex> String.valid? "∂"
#true
iex> String.valid? "∂og"
#false
