OnJava8-Examples/references/ImmutableStrings.java

// references/ImmutableStrings.java
// (c)2016 MindView LLC: see Copyright.txt
// We make no guarantees that this code is fit for any purpose.
// Visit http://mindviewinc.com/Books/OnJava/ for more book information.
// Demonstrating StringBuilder

public class ImmutableStrings {
  public static void main(String[] args) {
    String foo = "foo";
    String s = "abc" + foo + "def"
      + Integer.toString(47);
    System.out.println(s);
    // The "equivalent" using StringBuilder:
    StringBuilder sb =
      new StringBuilder("abc"); // Creates String
    sb.append(foo);
    sb.append("def"); // Creates String
    sb.append(Integer.toString(47));
    System.out.println(sb);
  }
}
/* Output:
abcfoodef47
abcfoodef47
*/