immutablestrings.java

来自「think in java TIJ-3rd-edition-code.zip」· Java 代码 · 共 19 行

//: appendixa:ImmutableStrings.java
// Demonstrating StringBuffer.
// {NoAutomaticTesting}

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 StringBuffer:
    StringBuffer sb = 
      new StringBuffer("abc"); // Creates String!
    sb.append(foo);
    sb.append("def"); // Creates String!
    sb.append(Integer.toString(47));
    System.out.println(sb);
  }
} ///:~