The forefather of Java. You can call C++ routines from Java via native method
calls. I learned C++ before Java. Much of my trouble at the beginning came from
presuming they worked the same way just because they look similar.
Differences between C++ and
Java
Learning Java is much like learning a foreign language. The sooner you start learning to think in the language,
rather than think in your native language (C++) and translating, the better
command of the language you develop. This is even truer of Java than most other computer languages because Java
is so strongly idiomatic. There are canned ways of doing almost everything. You build very little from scratch
from the primitive elements.
Java superficially looks a lot like C++, but nearly all my trouble learning
Java came from presuming it should work the same as C++ or
should have buried somewhere some feature I used in C++. It
works quite differently inside and has a completely different design philosophy. The rule of thumb is,
don’t presume Java works the same as C++ just because the syntax looks
the same. Java is a bit like an angler fish that dangles a C++ syntax lure to
seduce C++ programmers into trying Java (for their own good, of course), but it
works at a higher level of abstraction.
The major differences between C++ and Java are:
- An array of objects in C++ is a typically a set of structs packed one
right after the other in RAM (Random Access Memory). In Java, it is an array of pointers (aka references).
The pointers each point to an Object floating independently out there on the heap
somewhere.
- In Java, the sizes of int, long etc. are rigidly
defined in terms of bits. In C++ they are platform-dependent.
- In Java, the JVM (Java Virtual Machine) behaves at if it were big endian, even if internally it is actually little-endian. In
C++, the endianness is platform dependent.
- In Java, the choice of stack of heap allocation is handled automatically by the compiler (Sun’s javac
is not very bright always using the heap for objects, and the stack for local primitives and references) and
garbage collection of unreferenced objects is automatic. In C++, you have
manual control over where objects are created. The lifetime of objects created on the stack is automatically
controlled, deallocation and destructor automatically called when the method exits; this is known as
deterministic destruction. Whereas you have to manually control the lifetime of dynamic objects allocated with
new by invoking the destructor.
- In Java you don’t know for sure that all finalizers will be run; in C++ you do, because you invoke the destructors manually. You could write manually invoked
destructors in Java, but they would still not immediately recover the
RAM.
- In Java, references are constrained to point only to the beginnings of objects. You cannot do any form of
arithmetic on them. All you can do is compare them for equality. In C++, you
can do arithmetic on pointers and make pointers point anywhere in the address space. In Java, there is only one
way to address an object, via a reference which always points to the start of the object (or more precisely to
the start of the roughly 16 bytes of housekeeping fields preceding an object). In C++ there are many ways to address an object, including directly, via pointer arithmetic
into the middle of the object, via pointer, via address. In Java there is one addressing operator .. In C++, you use . & * ->
[].
- In Java, you cannot overload operators. In C++, you can.
- In Java, by default methods are virtual (overrideable). In C++, by
default, methods are non-virtual.
- Java object code (class files containing JVM byte codes) will run unmodified on any platform that supports
the JVM. C++ object code must be first linked to produce an executable
containing platform-specific machine instructions. It will run only on one platform.
- Java checks all subscripts that they are in bounds and all casts for validity. C++ does not.
- Java requires a JVM to execute. C++ programs are usually
freestanding.
- Java does not use a preprocessor. C makes extensive use of a macro preprocessor. C++ tends to use inline functions with less use of the macro preprocessor.
- Java does not allow multiple inheritance, though a class may implement several interfaces. C++ supports multiple inheritance.
- Java generics are a purely compile time type checking mechanism with type erasure at run time. C++ generics are templates, more like macro expansions of the code for each type.
- Java has built-in threads and synchronization. C++ relies on
platform-specific user-written thread libraries.
- Java has a vast standard library set, including AWT (Advanced Windowing Toolkit) and Swing. C++ has a
relatively modest standard set of methods, and relies on platform-specific GUI (Graphic User Interface) libraries.
- Java does not let you embed assembler or platform-dependent code. C++
lets you embed machine code assembler and have full access to the native platform API (Application Programming Interface).
- In Java, only one type of data can be stored in any variable. In C++, you
can have unions where alternate types of data are stored in the same slot in a struct.
- In Java, all classes derive from Object. In C++, classes have no common base.
- In Java, all method and field definitions must be inside some class. In C++, you can also define functions and variables independently of classes (and in fact,
you don’t need to define any classes at all to write a C++
program).
- Java is defined by Sun. C++ is defined by an ISO (International Standards Organisation) standard.
- Java has the final keyword and C++ has
const. C++ gives you finer control, but that
control can be overridden with a cast.
- Using JNI, Java can call C++/C
methods and vice versa.
- In C++, your main method’s first
argument is the name of the program that invoked it. In Java that is missing, largely because Java programs can
be invoked in so many way there is usually no executable name that directly invoked it.
- In C++ the main method is responsible for
telling the OS (Operating System) about the error code as its return value. In Java, the main is
void. Any method may call System. exit( retCode ).
- That just scratches the surface.
Microsoft C++ Keywords
| Microsoft C++ Keywords |
|---|
| __abstract |
__int |
__try_cast |
delete |
goto |
property |
true |
| __alignof |
__int6 |
__unaligned |
deprecated |
if |
protected |
try |
| __asm |
__int64 |
__unhook |
dllexport |
in |
public |
typedef |
| __assume |
__int8 |
__uuidof |
dllimport |
initonly |
ref |
typeid |
| __based |
__interface |
__value |
do |
inline |
register |
typename |
| __box |
__leave |
__virtual_inheritance |
double |
int |
reinterpret_cast |
union |
| __cdecl |
__m64 |
__w64 |
dynamic_cast |
interface |
return |
unsigned |
| __declspec |
__m8 |
__wchar_t |
each |
interior_ptr |
safecast |
using |
| __delegate |
__m8d |
abstract |
else |
literal |
sealed |
uuid |
| __event |
__m8i |
array |
enum |
long |
selectany |
value |
| __except |
__multiple_inheritance |
bool |
event |
mutable |
short |
virtual |
| __fastcall |
__nogc |
break |
explicit |
naked |
signed |
void |
| __finally |
__noop |
case |
extern |
namespace |
sizeof |
volatile |
| __finally |
__pin |
catch |
false |
new |
static |
wchar_t |
| __forceinline |
__property |
char |
finally |
noinline |
static_cast |
while |
| __gc |
__raise |
class |
float |
noreturn |
struct |
|
| __hook |
__sealed |
const |
for |
nothrow |
switch |
|
| __identifier |
__single_inheritance |
const_cast |
friend |
novtable |
template |
|
| __if_exists |
__stdcall |
continue |
friend_as |
nullptr |
this |
|
| __if_not_exists |
__super |
default |
gcnew |
operator |
thread |
|
| __inline |
__try |
delegate |
generic |
private |
throw |
|
Microsoft C++ sizeof
The sizes of various data types is platform dependent in C++, however here is
what they mean when developing for Microsoft Windows Vista C++.
| sizeof various data types is Microsoft C++ for Windows
Vista |
|---|
| C++ Type |
Closest
Java Type |
Bytes |
Bits |
Notes |
|---|
| Boolean |
Boolean |
1 |
8 |
1-byte Boolean, defined as unsigned char. |
| BOOLEAN |
Boolean |
1 |
8 |
1-byte Boolean |
| byte |
byte |
1 |
8 |
unsigned |
| BYTE |
byte |
1 |
8 |
unsigned |
| char |
byte |
1 |
8 |
8-bit signed chars. |
| unsigned char |
byte |
1 |
8 |
8-bit unsigned chars. |
| TCHAR |
char |
2 |
16 |
Unicode 16-bit chars. On older systems compiles to 8-bit. |
| wchar_t |
char |
2 |
16 |
Unicode 16-bit unsigned chars |
| WCHAR |
char |
2 |
16 |
Unicode 16-bit unsigned chars |
| short |
short |
2 |
16 |
signed |
| USHORT |
char |
2 |
16 |
unsigned |
| int |
int |
4 |
32 |
signed |
| size_t |
int |
4 |
32 |
unsigned |
| BOOL |
Boolean |
4 |
32 |
4-byte Boolean |
| long |
int |
4 |
32 |
signed |
| DWORD |
int |
4 |
32 |
unsigned |
| void* |
Object |
4 |
32 |
Pointer/Reference |
| float |
float |
4 |
32 |
IEEE (Institute of Electrical & Electronics Engineers) float |
| long long |
long |
8 |
64 |
signed |
| double |
double |
8 |
64 |
IEEE double |
See also the table of JNI types. I discovered the information
for the above table by running the following C++ program. You can modify it to
prepare a list of types and sizes for your C/ C++ projects.
C/C++
Header Libraries
To use a C/C++ method you need include its
prototype in a header file. Here are some of the most common header files and what the roughly contain:
| Common C/C++ header
files |
|---|
| Header |
Contents |
|---|
| afx.h |
includes Windows API and common C headers too. |
| afxcmn.h |
MFC (Microsoft Foundation Classes) support for Windows Common Controls |
| afxdtctl.h |
MFC support for Internet Explorer 4 Common Controls |
| afxext.h |
MFC extensions |
| afxwin.h |
MFC core and standard components |
| assert.h |
assert |
| conio.h |
getch, putch |
| ctype.h |
isUpper, isLower, toUpper |
| direct.h |
chdir, mkdir |
| dos.h |
DOS (Disk Operating System) API |
| fcntl.h |
open flags: O_RDONLY, _O_CREAT, _O_EXCL |
| io.h |
_chsize, _chmod, _lseek |
| jni.h |
Java JNI (Java Native Interface) library |
| mmsystem.h |
playsound |
| process.h |
exec, spawn |
| resource.h |
generated to include resources |
| share.h |
sharing flags: _SH_DENYRW, _SH_DENYWR, _SH_DENYRD, _SH_DENYNO, _SH_SECURE |
| stdafx.h |
standard precompiled header |
| stdio.h |
fclose, fgetc, printf, remove, rename, setvbuf |
| stdlib.h |
exit, putenv, splitpath |
| string.h |
strcpy, strcat, strcmp, strupr |
| sys\stat.h |
read/write permissions: _S_IREAD, _S_IWRITE |
| tchar.h |
16-bit chars, TCHAR |
| winbase.h |
time structures: _FILETIME, _SYSTEMTIME |
| windows.h |
Windows API |
Compiling
MS Visual C++ Express 2010 aka Visual is free, but you might ask you to
register, and you must use the IE (Internet Explorer) browser to do it. They ask you a ton of questions. The free version cannot
generate 64-bit code, though I have heard you can kludge it by downloading the MS SDK (Software Development Kit) and running it from
the command line. Visual Studio Pro (the cheapest version that can still generate 64-bit) will set you back
. I found the iso-image version (which includes various other
languages) oddly installed more quickly overall since it does not need to download code during the install. It has a bug. You must
arrange to put Program Files (x86)\Microsoft Visual Studio
10.0\Common7\ide\mspdb100.dll on the path. You can run X:\Program Files (x86)\Microsoft
Visual Studio 10.0\VC\bin\vcvars32.bat to patch the environment to fix the problem. It inserts all manner
of set parameters and adds many directories to your path. The normal Windows Update process updates Visual Studio
10.0.
You most commonly want to configure your project as a console application without precompiled headers.
When you use the GUI, the most interesting options are in right click properties for both the project and source files.
You will normally want to
right click Project Properties ⇒
General ⇒ Use of MFC ⇒ Use MFC in a Static Library
You will normally want to
right click Project Properties ⇒
C++ ⇒ Precompiled Headers ⇒ Not using precompiled headers.
Sometimes it is easier to edit the *.vcxproj files with a text editor. It can be so hard to find the dialog
in the GUI to control a field.
Right click Project Properties ⇒ C++
⇒ General and set it to
F:\Program Files (x86)\Microsoft Visual Studio 10.0\VC\include;C:\Program Files (x86)\Microsoft SDK s\Windows\v7.0A\Include;E:\Program Files (x86)\Java\jdk1.7.0_02\include;E:\Program Files (x86)\Java\jdk1.7.0_02\include\win32
to ensure JNI works.
The
command line equivalents to your GUI options should look something like this for debug:
| Microsoft C++ Express cl.exe Command Line Options |
|---|
| Debug |
Release |
Notes |
|---|
| /Od |
/O2 |
debug or optimise for speed |
|
/Oi |
intrinsic functions |
|
/GL |
link time optimisation |
| /D "WIN32" |
/D "WIN32" |
32-bit windows app |
| /D "_DEBUG" |
/D "NDEBUG" |
debugging on not |
| /D "_CONSOLE" |
/D "_CONSOLE" |
command line, console app |
| /D "_UNICODE" |
/D "_UNICODE" |
no multibyte sequences |
| /D "UNICODE" |
/D "UNICODE" |
no multibyte sequence |
| /EHsc |
/EHsc |
Enable C++ exceptions |
| /RTC1 |
|
run time checks |
| /MTd |
/MT |
multi-thread library |
|
/Gy |
function level linking |
| /Fo"Debug\\" |
/Fo"Release\\" |
where to put the object modules |
| /Fd"Debug\vc90.pdb" |
/Fd"Release\vc90.pdb" |
Program database |
| /W3 |
/W3 |
warning level |
| /Y- |
/Y- |
inhibit precompiled headers |
| /nologo |
/nologo |
no startup banner |
| /c |
/c |
compile without linking |
| /Zi |
|
Debug format |
| /TP |
/TP |
compile as C++ |
| /errorReport:prompt |
/errorReport:prompt |
prompt immediately |
| Microsoft Link link.exe Command Line Options |
|---|
| Debug |
Release |
Notes |
|---|
| /OUT:"E:\com\mindprod\splice\Debug\splice.exe" |
/OUT:"E:\com\mindprod\splice\Release\splice.exe" |
where exe file is generated |
| /INCREMENTAL:NO |
/INCREMENTAL:NO |
no incremental linking |
| /NOLOGO |
/NOLOGO |
no startup banner |
| /MANIFEST:NO |
/MANIFEST:NO |
no manifest |
| /DEBUG |
|
debug or release |
| /PDB:"E:\com\mindprod\splice\Debug\splice.pdb" |
|
Program database |
| /SUBSYSTEM:CONSOLE |
/SUBSYSTEM:CONSOLE |
command line console app |
|
/OPT:REF |
optimise by removing unreferenced code |
|
/OPT:ICF |
optimise by removing redundant ICFs |
|
/LTCG |
link time code generation |
| /DYNAMICBASE |
/DYNAMICBASE |
randomised image base |
| /NXCOMPAT |
/NXCOMPAT |
DEP compatible |
| /MACHINE:X86 |
/MACHINE:X86 |
Windows hardware |
| /ERRORREPORT:PROMPT |
/ERRORREPORT:PROMPT |
display errors immediately |
| kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib
oleaut32.lib uuid.lib odbc32.lib odbccp32.lib |
kernel32.lib user32.lib gdi32.lib winspool.lib comdlg32.lib advapi32.lib shell32.lib ole32.lib
oleaut32.lib uuid.lib odbc32.lib odbccp32.lib |
libraries |
/FD means incremental rebuild. It is not a real command line option. You can safely
delete compiler intermediate files: *aps *.ilk *.ipch *.ncb *.pbd *.pch. You must keep the
*.sln *.suo *.vcproj *.user.
For command line use, you also need SET environment variables to help the compiler find the include libraries
and the linker find the object libraries.
Redistributables
Microsoft Visual C++ needs a run time library called a redistributable package installed on the client machine.
Alternatively you can create standalone exe files.
Costs
- Microsoft Visual Studio Architect 2008
- Microsoft Visual Studio Enterprise 2008
- Microsoft Visual Studio Professional 2008
- Microsoft Visual Studio Standard 2008
- Microsoft Visual Studio
C++ Express 2010 free if you tell them information about yourself. Make
sure you use the /MT option to statically link, otherwise your clients will need to install the C++ runtime library.
Books
 |
recommend book⇒C++ For Java Programmers |
| by: | Mark Allen Weiss |
978-0-201-61246-2 | paperback |
|---|
| publisher: | Addison Wesley |
|---|
| published: | 1999-04-02 |
|---|
| This is the same title as Timothy A. Budd’s book. Note the direction. Most books presume you know C++ and need to learn Java. This one presumes you know Java and need to learn or brush up on C++ for doing JNI or related work. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒C++ For Java Programmers |
| by: | Timothy A. Budd |
978-0-13-919424-5 | hardcover |
|---|
| publisher: | Prentice Hall |
|---|
| published: | 2003-11-07 |
|---|
| This is the same title as Mark Allen Weiss’s book. Note the direction. ost books presume you know C++ and need to learn Java. This one presumes you know Java and need to learn or brush up on C++ for doing JNI or related work. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒Beginning Visual C++ 6 |
| by: | Ivor Horton |
978-1-86100-088-0 | paperback |
|---|
| publisher: | Wrox Press |
|---|
| published: | 1998-08 |
|---|
| A gentle, easy-paced introduction to C++. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒Accelerated C++: Practical Programming by Example |
| by: | Andrew R. Koenig, Barbara E. Moo |
978-0-201-70353-5 | paperback |
|---|
| | (born: 1952 age: 59) |
| publisher: | Addison-Wesley |
|---|
| published: | 2000-08-24 |
|---|
| Recommended for people who know Java and want to learn C++. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒The Design and Evolution of C++ |
| by: | Bjarne Stroustrup |
978-0-201-54330-8 | paperback |
|---|
| | (born: 1950-12-30 age: 61) |
| publisher: | Addison-Wesley |
|---|
| published: | 1994-04-08 |
|---|
| This is a fascinating book about the birth of a new computer language C++. He talks about the politics, the compromises, and the factors that made him design C++ the way it is. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒The C++ Programming Language (3rd Edition) |
| by: | Bjarne Stroustrup |
978-0-201-88954-3 | paperback |
|---|
| | (born: 1950-12-30 age: 61) |
978-0-201-70073-2 | hardcover |
|---|
| publisher: | Addison-Wesley |
|---|
| published: | 1997-06-30 |
|---|
| A reference manual for C++, rather formal. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒The Annotated C++ Reference Manual |
| by: | Margaret A. Ellis, Bjarne Stroustrup |
978-0-201-51459-9 | paperback |
|---|
| publisher: | Addison-Wesley |
|---|
| published: | 1990-01-11 |
|---|
| A book for language lawyers on the fine points of C++. It is not suitable for initially learning the language. It is really more aimed at compiler writers. It covers C++ implementation techniques including vtbls. |
|
| Greyed out stores probably do not have the item in stock |
 |
recommend book⇒Java Programming: Making the Move from C++ |
| by: | Joe Wigglesworth and Paula Lumby |
978-1-85032-922-0 | paperback |
|---|
| publisher: | International Thomson Computer Press |
|---|
| published: | 1998-07-21 |
|---|
| Does not discuss anything past Java 1.1. |
|
| Greyed out stores probably do not have the item in stock |
punctuation 0-9 A B C D E F G H I J K L M N O P Q R S T U V W X Y Z (all)
©1996-2012 2008-09-17 Roedy Green, Canadian Mind Products
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