CharSequence

所有已知子接口:

Name

所有已知实现类:

CharBuffer, DateIntervalFormat.FormattedDateInterval, FormattedNumber, RelativeDateTimeFormatter.FormattedRelativeDateTime, RichText, String, StringBuffer, StringBuilder
```
public interface CharSequence
```
A CharSequence is a readable sequence of char values. This interface provides uniform, read-only access to many different kinds of char sequences. A char value represents a character in the Basic Multilingual Plane (BMP) or a surrogate. Refer to Unicode Character Representation for details.
This interface does not refine the general contracts of the equals and hashCode methods. The result of comparing two objects that implement CharSequence is therefore, in general, undefined. Each object may be implemented by a different class, and there is no guarantee that each class will be capable of testing its instances for equality with those of the other. It is therefore inappropriate to use arbitrary CharSequence instances as elements in a set or as keys in a map.

从以下版本开始:

1.4

方法概要

所有方法实例方法抽象方法默认方法
限定符和类型	方法	说明
`char`	`charAt(int index)`	Returns the `char` value at the specified index.
`default IntStream`	`chars()`	Returns a stream of `int` zero-extending the `char` values from this sequence.
`default IntStream`	`codePoints()`	Returns a stream of code point values from this sequence.
`int`	`length()`	Returns the length of this character sequence.
`CharSequence`	`subSequence(int start, int end)`	Returns a `CharSequence` that is a subsequence of this sequence.
`String`	`toString()`	Returns a string containing the characters in this sequence in the same order as this sequence.

- 方法详细资料
  - length
```
int length()
```
    Returns the length of this character sequence. The length is the number of 16-bit chars in the sequence.
    
    返回:
    
    the number of chars in this sequence
  - charAt
```
char charAt(int index)
```
    Returns the char value at the specified index. An index ranges from zero to length() - 1. The first char value of the sequence is at index zero, the next at index one, and so on, as for array indexing.
    If the char value specified by the index is a surrogate, the surrogate value is returned.
    
    参数:
    
    index - the index of the char value to be returned
    
    返回:
    
    the specified char value
    
    抛出:
    
    IndexOutOfBoundsException - if the index argument is negative or not less than length()
  - subSequence
```
CharSequence subSequence(int start,
                         int end)
```
    Returns a CharSequence that is a subsequence of this sequence. The subsequence starts with the char value at the specified index and ends with the char value at index end - 1. The length (in chars) of the returned sequence is end - start, so if start == end then an empty sequence is returned.
    
    参数:
    
    start - the start index, inclusive
    
    end - the end index, exclusive
    
    返回:
    
    the specified subsequence
    
    抛出:
    
    IndexOutOfBoundsException - if start or end are negative, if end is greater than length(), or if start is greater than end
  - toString
```
String toString()
```
    Returns a string containing the characters in this sequence in the same order as this sequence. The length of the string will be the length of this sequence.
    
    覆盖:
    
    toString 在类中 Object
    
    返回:
    
    a string consisting of exactly this sequence of characters
  - chars
```
default IntStream chars()
```
    Returns a stream of int zero-extending the char values from this sequence. Any char which maps to a surrogate code point is passed through uninterpreted.
    If the sequence is mutated while the stream is being read, the result is undefined.
    
    返回:
    
    an IntStream of char values from this sequence
    
    从以下版本开始:
    
    1.8
  - codePoints
```
default IntStream codePoints()
```
    Returns a stream of code point values from this sequence. Any surrogate pairs encountered in the sequence are combined as if by Character#toCodePoint and the result is passed to the stream. Any other code units, including ordinary BMP characters, unpaired surrogates, and undefined code units, are zero-extended to int values which are then passed to the stream.
    If the sequence is mutated while the stream is being read, the result is undefined.
    
    返回:
    
    an IntStream of Unicode code points from this sequence
    
    从以下版本开始:
    
    1.8

接口 CharSequence

方法概要

方法详细资料

length

charAt

subSequence

toString

chars

codePoints