java.lang
Interface CharSequence
java.lang.Object
|
+--java.lang.CharSequence
public interface CharSequence
General functions on a sequence of chars. This interface is implemented
by
String
,
StringBuffer
and
CharBuffer
to give a uniform way to get chars at a certain
index, the number of characters in the sequence and a subrange of the
chars. Indexes start at 0 and the last index is
length()-1
.
Even when classes implement this interface they are not always
exchangeble because they might implement their compare, equals or hash
function differently. This means that in general one should not use a
CharSequence
as keys in collections since two sequences
with the same chars at the same indexes with the same length might not
have the same hash code, be equal or be comparable since the are
represented by different classes.
Since:Author:- Mark Wielaard (mark@klomp.org)
charAt
public char charAt(int i)
Returns the character at the given index.
Parameters:
Returns:
- the character at that location
Throws:
length
public int length()
Returns the length of the sequence. This is the number of 16-bit
characters in the sequence, which may differ from the length of the
underlying encoding.
Returns:
subSequence
public CharSequence subSequence(int begin, int end)
Returns a new CharSequence of the indicated range.
Parameters:
Returns:
Throws:
toString
public String toString()
Returns the complete CharSequence
as a String
.
Classes that implement this interface should return a String
which contains only the characters in the sequence in the correct order.
Returns:
- the character sequence as a String
String
,StringBuffer
andCharBuffer
to give a uniform way to get chars at a certain index, the number of characters in the sequence and a subrange of the chars. Indexes start at 0 and the last index islength()-1
.Even when classes implement this interface they are not always exchangeble because they might implement their compare, equals or hash function differently. This means that in general one should not use a
CharSequence
as keys in collections since two sequences with the same chars at the same indexes with the same length might not have the same hash code, be equal or be comparable since the are represented by different classes.