//程序 public static void main(String [] args) { int x=2; int b=(x++)*3; System.out.println(b); } //字节码 public static main([Ljava/lang/String;)V L0 LINENUMBER 7 L0 ICONST_2 ISTORE 1 L1 LINENUMBER 8 L1 ILOAD 1 IINC 1 1 ICONST_3 IMUL ISTORE 2 L2 LINENUMBER 9 L2 GETSTATIC java/lang/System.out : Ljava/io/PrintStream; ILOAD 2 INVOKEVIRTUAL java/io/PrintStream.println (I)V L3 LINENUMBER 10 L3 RETURN L4 LOCALVARIABLE args [Ljava/lang/String; L0 L4 0 LOCALVARIABLE x I L1 L4 1 LOCALVARIABLE b I L2 L4 2 MAXSTACK = 2 MAXLOCALS = 3 直接上程序和上字节码