Common Java classes -StringBuffer categories:

. 1  StringBuffer class:
 2  string object may be modified to create StringBuffer class, String object can not be modified to create
 3 constructor: StringBuffer () = StringBuffer new new StringBuffer ();
 . 4 StringBuffer (); // default initial hold 16 characters 
. 5 StringBuffer ( int size);
 . 6  the StringBuffer (String S);
 . 7  
. 8 stringbuffer.length (); method to get the length of the sequence of characters stored in the entity -> initial default is 0
 . 9 stringbuffer.capacity (); a method of acquiring an actual current entity capacity -> initial default 16
 10  
. 11  the StringBuffer common methods:
 12  calls .append () method can
 13 is the StringBuffer the append (String S); //Added to the back of the string s StringBuffer StringBuffer object and return the object reference 
14 StringBuffer the append ( int n-); // converted to type int word string is then added StringBuffer object 
15 StringBuffer the append (Object Object ); // a string object StringBuffer object is added to the object 
16 StringBuffer the append ( Long . 17  StringBuffer the append (n-Boolean);
 18 is StringBuffer the append ( a float n-);
 . 19 StringBuffer the append ( Double n-);
 20 is StringBuffer the append ( char C);
 21 is  public  char the charAt ( int index);// single character index parameter to obtain specified position 
22 is  public  void setCharAt ( int index, char CH); // string is replaced with the string at index CH 
23 is the StringBuffer INSERT ( int index, String STR); // The string str inserted position index 
24  public the StringBuffer Reverse (); // string flipping 
25 the StringBuffer delete ( int Start, int End); // remove from start-> end-1 of this section of the string 
26 is the StringBuffer Replace ( int Start, int End, String str); //The replacement string string str [start, end-1] of this interval