programming-for-dummies

Teaching Languages 57
near future. If you study Logo just to explore new ways of thinking, you
won’t be disappointed.
Book I
Chapter 3
Logo relies primarily on an interpreter instead of a compiler because an
interpreter can give you instant feedback for each command you type into
the computer.
The philosophy of Pascal
Unlike BASIC or Logo, which was designed to make programming interactive
and fun, Pascal was designed to force programmers to design and organize a
program using structured programming techniques (see Book I, Chapter 2).
Types of
Programming
Languages
Early versions of BASIC made it easy to write spaghetti programs because a
BASIC program consisted essentially of one glob of commands lumped
together inside a single file. The larger your BASIC program got, the more
confusing it became to read and understand.
Pascal tackled this problem by encouraging programmers to divide a large
program into smaller subprograms. Each subprogram would solve a single
problem and act like a Lego building block. Slap enough subprograms
together and you could create a much larger and more complicated program.
Although Pascal was initially designed to teach good programming habits,
Pascal eventually became popular for writing many commercial programs.
Early versions of the Macintosh operating system were even written in
Pascal. Computer scientists eventually added so many features to Pascal
that Pascal’s power could nearly rival that of the C language.
For a brief period of time during the 1980s, Pascal was arguably more popular
than BASIC. One of the most popular Pascal compilers of all time was Borland
Software’s Turbo Pascal, which later morphed into the event-driven, objectoriented
programming language that’s now known as Delphi (www.turbo
explorer.com).
Pascal’s greatest strength was that it was almost as easy to understand as
BASIC and almost as fast, efficient, and powerful as C. Reading a Pascal program
was much easier than reading a similar C program, as the following
programs demonstrate.
Program Hello_World;
Begin
Writeln (‘Hello World!’);
End.