String 對比 StringBuilder

Microsoft Windows XP [版本 5.1.2600]
(C) 版權所有 1985-2001 Microsoft Corp.

C:\Documents and Settings\zhengwei>cd
C:\Documents and Settings\zhengwei

C:\Documents and Settings\zhengwei>cd "C:\Documents and Settings\zhengwei\桌面

C:\Documents and Settings\zhengwei\桌面>javac T.java

C:\Documents and Settings\zhengwei\桌面>java T
0123456789

C:\Documents and Settings\zhengwei\桌面>javap -c T
Compiled 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:   return

public 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/lan
g/StringBuilder;
   31:  invokevirtual   #7; //Method java/lang/StringBuilder.toString:()Ljava/la
ng/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/Str
ing;)V
   48:  return

}


C:\Documents and Settings\zhengwei\桌面>javac T2.java

C:\Documents and Settings\zhengwei\桌面>javap -c T2
Compiled 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:   return

public 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/lan
g/StringBuilder;
   33:  invokevirtual   #7; //Method java/lang/StringBuilder.toString:()Ljava/la
ng/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/la
ng/String;
   53:  invokevirtual   #9; //Method java/io/PrintStream.println:(Ljava/lang/Str
ing;)V
   56:  return

}


C:\Documents and Settings\zhengwei\桌面>