String 对比 StringBuilder

Microsoft Windows XP [版本 5.1.2600](C) 版权所有 1985-2001 Microsoft Corp.C:\Documents and Settings\zhengwei>cdC:\Documents and Settings\zhengweiC:\Documents and Settings\zhengwei>cd "C:\Documents and Settings\zhengwei\桌面C:\Documents and Settings\zhengwei\桌面>javac T.javaC:\Documents and Settings\zhengwei\桌面>java T0123456789C:\Documents and Settings\zhengwei\桌面>javap -c TCompiled from "T.java"public class T extends java.lang.Object{public T();  Code:   0:   aload_0   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V   4:   returnpublic static void main(java.lang.String[]);  Code:   0:   ldc     #2; //String   2:   astore_1   3:   iconst_0   4:   istore_2   5:   iload_2   6:   bipush  10   8:   if_icmpge       41   11:  new     #3; //class java/lang/StringBuilder   14:  dup   15:  invokespecial   #4; //Method java/lang/StringBuilder."<init>":()V   18:  aload_1   19:  invokevirtual   #5; //Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;   22:  ldc     #2; //String   24:  invokevirtual   #5; //Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;   27:  iload_2   28:  invokevirtual   #6; //Method java/lang/StringBuilder.append:(I)Ljava/lang/StringBuilder;   31:  invokevirtual   #7; //Method java/lang/StringBuilder.toString:()Ljava/lang/String;   34:  astore_1   35:  iinc    2, 1   38:  goto    5   41:  getstatic       #8; //Field java/lang/System.out:Ljava/io/PrintStream;   44:  aload_1   45:  invokevirtual   #9; //Method java/io/PrintStream.println:(Ljava/lang/String;)V   48:  return}C:\Documents and Settings\zhengwei\桌面>javac T2.javaC:\Documents and Settings\zhengwei\桌面>javap -c T2Compiled from "T2.java"public class T2 extends java.lang.Object{public T2();  Code:   0:   aload_0   1:   invokespecial   #1; //Method java/lang/Object."<init>":()V   4:   returnpublic static void main(java.lang.String[]);  Code:   0:   new     #2; //class java/lang/StringBuilder   3:   dup   4:   invokespecial   #3; //Method java/lang/StringBuilder."<init>":()V   7:   astore_1   8:   iconst_0   9:   istore_2   10:  iload_2   11:  bipush  10   13:  if_icmpge       46   16:  aload_1   17:  new     #2; //class java/lang/StringBuilder   20:  dup   21:  invokespecial   #3; //Method java/lang/StringBuilder."<init>":()V   24:  ldc     #4; //String   26:  invokevirtual   #5; //Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;   29:  iload_2   30:  invokevirtual   #6; //Method java/lang/StringBuilder.append:(I)Ljava/lang/StringBuilder;   33:  invokevirtual   #7; //Method java/lang/StringBuilder.toString:()Ljava/lang/String;   36:  invokevirtual   #5; //Method java/lang/StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;   39:  pop   40:  iinc    2, 1   43:  goto    10   46:  getstatic       #8; //Field java/lang/System.out:Ljava/io/PrintStream;   49:  aload_1   50:  invokevirtual   #7; //Method java/lang/StringBuilder.toString:()Ljava/lang/String;   53:  invokevirtual   #9; //Method java/io/PrintStream.println:(Ljava/lang/String;)V   56:  return}C:\Documents and Settings\zhengwei\桌面>