String Buffer class

Key Points :-

• used to created mutable (modifiable) string.
• Mutable :- Which can be changed.
• is thread-safe i.e. multiple threads cannot access it simultaneously.

Methods :-

• public synchronized StringBuffer append(String s)
• public synchronized StringBuffer insert(int offset, String s)
• public synchronized StringBuffer replace(int startIndex, int endIndex, String str)
• public synchronized StringBuffer delete(int startIndex, int endIndex)
• public synchronized StringBuffer reverse()
• public int capacity()
• public void ensureCapacity(int minimumCapacity)
• public char charAt(int index)
• public int length()
• public String substring(int beginIndex)
• public String substring(int beginIndex, int endIndex)

Example Showing diffrence between String and String Buffer implementation :-

class Test {
 public static void main(String args[])
 {
  String str = "study";
  str.concat("tonight");
  System.out.println(str);      // Output: study

  StringBuffer strB = new StringBuffer("study");
  strB.append("tonight");
  System.out.println(strB);    // Output: studytonight
 }
}