Editing Computer program (section)

==Example computer program==

The [["Hello, World!" program]] is used to illustrate a language's basic [[Syntax (programming languages)|syntax]]. The syntax of the language [[Dartmouth BASIC|BASIC]] (1964) was intentionally limited to make the language easy to learn.<ref name="cpl_3rd-ch2-30_quote1">{{cite book
  | last = Wilson
  | first = Leslie B.
  | title = Comparative Programming Languages, Third Edition
  | publisher = Addison-Wesley
  | year = 2001
  | page = 30
  | isbn = 0-201-71012-9
  | quote = Their intention was to produce a language that was very simple for students to learn[.]
}}</ref> For example, [[Variable (computer science)|variables]] are not [[Declaration (computer programming)|declared]] before being used.<ref name="cpl_3rd-ch2-31">{{cite book
  | last = Wilson
  | first = Leslie B.
  | title = Comparative Programming Languages, Third Edition
  | publisher = Addison-Wesley
  | year = 2001
  | page = 31
  | isbn = 0-201-71012-9
}}</ref> Also, variables are automatically initialized to zero.<ref name="cpl_3rd-ch2-31"/> Here is an example computer program, in Basic, to [[average]] a list of numbers:<ref name="cpl_3rd-ch2-30">{{cite book
  | last = Wilson
  | first = Leslie B.
  | title = Comparative Programming Languages, Third Edition
  | publisher = Addison-Wesley
  | year = 2001
  | page = 30
  | isbn = 0-201-71012-9
}}</ref>
<syntaxhighlight lang="basic">
10 INPUT "How many numbers to average?", A
20 FOR I = 1 TO A
30 INPUT "Enter number:", B
40 LET C = C + B
50 NEXT I
60 LET D = C/A
70 PRINT "The average is", D
80 END
</syntaxhighlight>

Once the mechanics of basic computer programming are learned, more sophisticated and powerful languages are available to build large computer systems.<ref name="cpl_3rd-ch2-30_quote2">{{cite book
  | last = Wilson
  | first = Leslie B.
  | title = Comparative Programming Languages, Third Edition
  | publisher = Addison-Wesley
  | year = 2001
  | page = 30
  | isbn = 0-201-71012-9
  | quote = The idea was that students could be merely casual users or go on from Basic to more sophisticated and powerful languages[.]
}}</ref>