D Documentation
in
[ Log in ]
[ Home ][ Up ]
  1. Introduction
    1. A simple tutorial
    2. Switching to D
      1. From C/C++
      2. From Java
      3. From Pascal/Delphi
      4. From PHP :)
    3. An advanced tutorial
  2. Language Reference
    1. General syntax
    2. Statements
    3. Types
    4. Error Handling
    5. Memory Management
  3. Std. runtime library (Phobos)
    1. std.base64
    2. std.boxer
    3. std.compiler
    4. std.conv
    5. std.ctype
    6. std.date
    7. std.file
    8. std.format
    9. std.gc
    10. std.intrinsic
    11. std.math
    12. std.md5
    13. std.mmfile
    14. std.outbuffer
    15. std.path
    16. std.process
    17. std.random
    18. std.recls
    19. std.regexp
    20. std.socket
    21. std.socketstream
    22. std.stdint
    23. std.stdio
    24. std.stream
    25. std.string
    26. std.system
    27. std.thread
    28. std.uri
    29. std.utf
    30. std.zip
    31. std.zlib
  4. Tango
    1. Introduction
    2. Tutorials
    3. API Reference
  5. Libraries and Tools
    1. mango
    2. Build
  6. Related Links
  7. About this documentation
    1. The docwiki software
    2. TTT
    3. Docwiki reference
    4. Style guide
    5. FAQ
    6. To do
From Java
Switching from Java to D is not a big step. There are a few differences because D is compiled for native code. As both languages are somehow influenced by or inherited from C or C++ syntax, there won't be a big problem :-)

Let me show you some D code that works and is very similar to java code:

// a class called Foo
class Foo
{
  // a variable
  int myInteger;

  // this is the constructor!!
  this()
  {                  
    myInteger = 1;
  }

  // a function :-)
  int bar()
  {               
    for (ubyte i=0; i<2; i++) {
      myInteger *= 2;
    }
    return myInteger;
  }

} // end of class Foo

void main()
{
  // creates a new class of Foo
  Foo myFoo   = new Foo();   

  // calls the function bar in foo three times.
  writefln("%d",myFoo.bar()); 
  writefln("%d",myFoo.bar());
  writefln("%d",myFoo.bar());
}

Output:
4
16
64

Difference: In D, we don't have to use a class name that is same name as the file and we import std.stdio to write to the display:

// Import standard-in-out
import std.stdio;

// Main function
int main(char[][] args)
{
  char[] world() {
    return "world!";
  }
  writefln("Hello "~world());

  // We have to return with a int to exit the program (0 means "no error").
  return 0;
}

Difference: The main function must return an int to the system.

Difference: In D "+" and "~" are not the same! The first one (plus) is only for numbers (int b=5+3, int a=2+b) and the concatenation ("~") is only for arrays (which strings are):

char[] str   = "Paradise";
char[] text  = "Welcome to "~str~".";


See also:
Language Reference, An advanced tutorial: File read and write, Java to D
PHP docwiki written by Markus Dangl. Best viewed with Mozilla Firefox.
This is the inofficial wiki for documenting the D programming language.
- Profiler -
Time for site generation: 0.0788 s