Software for Translators Barcelona, January 2002

Content  Programming and Languages  Origins  4 Languages  The Programming Cylcle  Edit  Compile  Execute  Exercises: Java Programming  Language Elements

Programming and Languages

The ancient days (1950)

Punched Paper A C B D EF „Registers“ ld A, 1 1 A ld B, 2 2 B add A,B 3 A

The old days (1970)

Computer Memory A C B D EF „Registers“ Program Counter B ld A, 1 01 PC 1 A ld B, 202 PC 2 B add A,B 03 PC 3 A

Basic (1980)

10set a = 1; 20set b = 2; 30set a = a + b; 40print a; => 3 A C B D EF 2 B3 A

Basic (1980)  print 1+2; => 3 A C B D EF 2 B3 A

Programming Languages Historic  PL/1  Cobol  Fortran  Basic Object Oriented  Smalltalk  C  C++  Java  Python Exotic  Prolog  Lisp Scripting  Shell  Perl  TCL Database  SQL  dBase

4 Languages  Basic  Visual Basic  Java  HTML

Basic Example 10 rem Just print Hello World. 20 print ´Hello World´ => Hello World

Visual Basic Example '############################################### '# # # # '# # This program places a text into a # # '# # a text box for viewing. # # '# # # # '############################################### Dim i As Integer Private Sub Command1_Click() On Error Resume Next CommonDialog1.ShowOpen i = FreeFile Open CommonDialog1.filename For Input As #i Text1.Text = Input(LOF(i), i) Close #i End Sub

Java Example // This example is from Java in a Nutshell. // Copyright (c) 1997 by David Flanagan public class Hello { public static void main(String[] args) { System.out.println("Hello World!"); } => Hello World

HTML Example Hello World! Text Editor: HTML Internet Explorer

The Programming Cycle

EditExecute Compile javac HelloWorld.java java HelloWorld

Edit

Compile javac HelloWorld.java

Execute java HelloWorld

Language Elements

 Comments  // Comment  /* Comment */  % Comment  Keywords:  FOR  NEXT  WHILE  DO  I F  Strings:  “Hello World”  ´Hello World´  ‘Hello World’  Identifiers:  ClassName  x, y, z  Parenthesis:  (foo bar)  [foo bar]  {foo bar}

Comments // This example is from Java in a Nutshell. // Copyright (c) 1997 by David Flanagan public class Hello { public static void main(String[] args) { System.out.println("Hello World!"); }

Keywords // This example is from Java in a Nutshell. // Copyright (c) 1997 by David Flanagan public class Hello { public static void main(String[] args) { System.out.println("Hello World!"); }

Strings // This example is from Java in a Nutshell. // Copyright (c) 1997 by David Flanagan public class Hello { public static void main(String[] args) { System.out.println("Hello World!"); }

Identifiers // This example is from Java in a Nutshell. // Copyright (c) 1997 by David Flanagan public class Hello { public static void main(String[] args) { System.out.println("Hello World!"); }