java.lang

Interface CharSequence

All Known Implementing Classes:

String, StringBuffer

public interface CharSequence

A CharSequence is a readable sequence of characters. This interface provides uniform, read-only access to many different kinds of character sequences.

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.

Since:

1.4

Version:

1.7 05/03/12

Author:

Mike McCloskey

Method Summary

Methods

Modifier and Type	Method and Description
char	charAt(int index) Returns the character at the specified index.
int	length() Returns the length of this character sequence.
CharSequence	subSequence(int start, int end) Returns a new character sequence 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.

Method Detail

length

int length()

Returns the length of this character sequence. The length is the number of 16-bit Unicode characters in the sequence.

Returns:

the number of characters in this sequence

charAt

char charAt(int index)

Returns the character at the specified index. An index ranges from zero to length() - 1. The first character of the sequence is at index zero, the next at index one, and so on, as for array indexing.

Parameters:

index - the index of the character to be returned

Returns:

the specified character

Throws:

IndexOutOfBoundsException - if the index argument is negative or not less than length()

subSequence

CharSequence subSequence(int start,
                       int end)

Returns a new character sequence that is a subsequence of this sequence. The subsequence starts with the character at the specified index and ends with the character at index end - 1. The length of the returned sequence is end - start, so if start == end then an empty sequence is returned.

Parameters:

start - the start index, inclusive

end - the end index, exclusive

Returns:

the specified subsequence

Throws:

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.

Overrides:

toString in class Object

Returns:

a string consisting of exactly this sequence of characters