Testing.java source file: public class Testing { static public void main(String args[]) { int c; for (c=0; c<10; c++) { System.out.println(c); } } } Testing.class disassembled with javap -c Testing: Compiled from "Testing.java" public class Testing extends java.lang.Object{ public Testing(); Code: 0: aload_0 1: invokespecial #1; //Method java/lang/Object."":()V 4: return public static void main(java.lang.String[]); Code: 0: iconst_0 1: istore_1 2: iload_1 3: bipush 10 5: if_icmpge 21 8: getstatic #2; //Field java/lang/System.out:Ljava/io/PrintStream; 11: iload_1 12: invokevirtual #3; //Method java/io/PrintStream.println:(I)V 15: iinc 1, 1 18: goto 2 21: return } Output of naken_java compiled in DEBUG mode: MagicNumber: 0xcafebabe MinorVersion: 0 MajorVersion: 50 (6.0) ConstantCount: 28 1) MethodRef: class_index=5 name_and_type_index=15 2) FieldRef: class_index=16 name_and_type_index=17 3) MethodRef: class_index=18 name_and_type_index=19 4) Class: name_index=20 5) Class: name_index=21 6) UTF8: 7) UTF8: ()V 8) UTF8: Code 9) UTF8: LineNumberTable 10) UTF8: main 11) UTF8: ([Ljava/lang/String;)V 12) UTF8: StackMapTable 13) UTF8: SourceFile 14) UTF8: Testing.java 15) NameAndType: name_index=6 descriptor_index=7 16) Class: name_index=22 17) NameAndType: name_index=23 descriptor_index=24 18) Class: name_index=25 19) NameAndType: name_index=26 descriptor_index=27 20) UTF8: Testing 21) UTF8: java/lang/Object 22) UTF8: java/lang/System 23) UTF8: out 24) UTF8: Ljava/io/PrintStream; 25) UTF8: java/io/PrintStream 26) UTF8: println 27) UTF8: (I)V 28) MethodRef: class_index=5 name_and_type_index=15 AccessFlags: 33 public super ThisClass: 4 SuperClass: 5 InterfaceCount: 0 FieldCount: 0 MethodCount: 2 ----- 0 ----- access_flags: 1 public name_index: 6 descriptor_index: 7 attribute_count: 1 ----- 0 ----- name_index: 8 length: 29 info: { 00 01 00 01 00 00 00 05 2a b7 00 01 b1 00 00 00 01 00 09 00 00 00 06 00 01 00 00 09 00 } ----- 1 ----- access_flags: 9 public static name_index: 10 descriptor_index: 11 attribute_count: 1 ----- 0 ----- name_index: 8 length: 71 info: { 00 02 00 02 00 00 00 16 03 3c 1b 10 0a a2 00 10 b2 00 02 1b b6 00 03 84 01 01 a7 ff f0 b1 00 00 00 02 00 09 00 00 00 12 00 04 00 00 00 08 00 08 00 0a 00 0f 00 08 00 15 00 0c 00 0c 00 00 00 07 00 02 fc 00 02 01 12 } Attributes: 1 ----- 0 ----- name_index: 13 length: 2 info: { 00 0e } pc=8 max_stack=2 max_locals=2 code_len=22 pc=0 opcode=3 (0x03) ---- Stack Dump (size=1) ----- 0 Integer pc=1 opcode=60 (0x3c) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 0 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 0 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 0 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 0 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 1 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 1 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 1 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 1 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 2 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 2 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 2 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 2 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 3 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 3 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 3 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 3 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 4 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 4 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 4 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 4 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 5 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 5 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 5 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 5 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 6 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 6 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 6 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 6 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 7 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 7 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 7 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 7 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 8 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 8 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 8 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 8 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 9 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 9 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=8 opcode=178 (0xb2) ---- Stack Dump (size=1) ----- 2 Ref pc=11 opcode=27 (0x1b) ---- Stack Dump (size=2) ----- 2 Ref 9 Integer pc=12 opcode=182 (0xb6) Call to class: java/io/PrintStream Call to method: println Call to signature: (I)V 9 ---- Stack Dump (size=0) ----- pc=15 opcode=132 (0x84) ---- Stack Dump (size=0) ----- pc=18 opcode=167 (0xa7) ---- Stack Dump (size=0) ----- pc=2 opcode=27 (0x1b) ---- Stack Dump (size=1) ----- 10 Integer pc=3 opcode=16 (0x10) ---- Stack Dump (size=2) ----- 10 Integer 10 Integer pc=5 opcode=162 (0xa2) ---- Stack Dump (size=0) ----- pc=21 opcode=177 (0xb1)