Answers for "string buffer and string builder"

stringbuffer vs stringbuilder java

The StringBuffer and StringBuilder class both produces mutable string objects.
 The main difference between them is that StringBuffer is thread safe;
 StringBuilder is not thread safe.

string buffer and string builder

The StringBuffer and StringBuilder 
class both produces mutable string objects.
 The main difference between 
 them is that StringBuffer is thread safe;
 StringBuilder is not thread safe.

string builder vs string buffer

String vs StringBuilder vs StringBuffer:
String: Immutable version char sequences
StringBuilder: mutable version char sequences,
not synchronized
StringBuffer: mutable version char sequences,
synchronized , thread-safe, slow
String str = new String("a")
StringBuilder s2 = new StringBuilder("B") // MUTABLE
StringBuffer s2 = new StringBuffer("c") // Synchronized