Programming Fundamentals: Program Structure

Virtually all structured programs share a similar overall pattern:
  • Statements to establish the start of the program
  • Variable declaration
  • Program statements (blocks of code)
The following is a simple example of a program written in several different programming languages. We call this the “Hello World” example since all the program does is print “Hello World” on the computer screen.
LanguageExample program
“C”
#include <stdio.h>
void main() {
    printf("Hello World");
}
C++
#include <iostream>
int main() {
    cout << "Hello World";
    return 0;
}
Pascal
program helloworld (output);
begin
    writeln('Hello World');
end.
Oracle PL/SQL
CREATE OR REPLACE PROCEDURE helloworld AS
BEGIN
    DBMS_OUTPUT.PUT_LINE('Hello World');
END;
Java
class helloworld {
    public static void main (String args []) {
       System.out.println ("Hello World");
    }
}
Perl
#!/usr/local/bin/perl -w print "Hello World";
Basic
print "Hello World"
Note that the Perl and Basic languages are technically not compiled languages. These language statements are “interpreted” as the program is running.