string模块¶

chars/2

结构:
chars(Character, Number) -> String
chars(Character, Number, Tail) -> String
类型:
Character = char()
Number = integer() >= 0
Tail = String = string()

实例:

erl> string:chars($-,5).
"-----"

chr/2

结构:

chr(String, Character) -> Index

类型:

String = string()
Character = char()
Index = integer() >= 0

说明:

Return the index of first/last occurrence of Character in String.
0 returned if the character does not occur.

strip/1/2/3

结构:

strip/1 === strip(String, both).
strip/2 === strip(String, Direction, " ").


strip(String, Direction, Character) -> Stripped
类型:
String = Stripped = string()
Direction = left | right | both
Character = char()

说明:

根据需要去除字串前(后)的Character

实例:

> string:strip("...Hello.....", both, $.).
"Hello"
> string:strip("   Hello    ", both).
"Hello"
> string:strip("   Hello    ").
"Hello"

str/2

结构:

str(String, SubString) -> Index
类型:
String = SubString = string()
Index = integer() >= 0

说明:

返回每一次出现的SubString在String中开始的位置.
如String不存在SubString则返回0

实例:

> string:str(" Hello Hello World World ", "Hello World").
8

tokens/2

结构:

tokens(String, SeparatorList) -> Tokens
类型
String = SeparatorList = string()
Tokens = [Token :: nonempty_string()]

说明:

Return a list of tokens in ``String`` , separated by the characters in `SeparatorList`

实例:

% 按空格or字符x分割
> lists:tokens("abc defxxghix jkl", "x ").
["abc", "def", "ghi", "jkl"]

to_integer/1

用法:

to_integer(String) -> {Int, Rest} | {error, Reason}

类型:
String = string()
Int = integer()
Rest = string()
Reason = no_integer | not_a_list

说明:

String以数字开头,
Int: 返回最前面的数字
Rest: 数字后面剩余的string

实例:

> {I1,Is} = string:to_integer("33+22"),
> {I2,[]} = string:to_integer(Is),
> I1-I2.
 11
> string:to_integer("0.5").
 {0,".5"}
> string:to_integer("x=2").
 {error,no_integer}