SE450: A Builder in the Java APIs [2015/09/15]

SE450: Taxonomy: A Builder in the Java APIs [59/63]

java.lang.StringBuilder is a builder for java.lang.String.

   +---------------------+ <<creates>>  +---------------+
   | StringBuilder        |- - - - - - ->| <<immutable>> |
   +---------------------+              |     String    |
   | append(String):void |              +---------------+
   | toString():String   |
   +---------------------+

Here is an example, showing the usage:

file:Main.java [source] [doc-public] [doc-private]

package basics.stringbuffer;
public class Main {
  private Main() {}
  static public void main (String[] args) {
    //stdlib.Trace.graphvizShowSteps (true); stdlib.Trace.run ();
    StringBuilder b = new StringBuilder();
    b.append("I am ");
    b.append("a dog");
    String s = b.toString();
    System.out.println(s);
    b.append("matic jerk");
    System.out.println(s);
  }
}