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@INDEX "ARB:Misc/Index.Text/Main"
@HELP "ARB:Misc/Help/Main"
@NODE "Main" "ARexx For Beginners - Article 4 - Numbers & Strings"

@{B}@{U}@{JCENTER}AREXX FOR BEGINNERS

ARTICLE 4 - NUMBERS AND STRINGS

BY FRANK BUNTON@{UB}@{UU}

@{" COPYRIGHT © FRANK P. BUNTON 1995-1998 " LINK "ARB:Misc/Read_Me_First!!/Copyright"}

@{" Numbers " LINK "Numbers"}
@{" Strings " LINK "Strings"}


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@NODE "Numbers" "ARexx For Beginners - Article 4 - Numbers"

@{B}@{U}@{JCENTER}NUMBERS@{UB}@{UU}
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Every one knows what numbers are so why talk about them?

Mainly to differentiate them from strings! But also to talk a little
about different ways that numbers can be displayed and about the
different number systems that are available.

We will learn quite a bit about numbers and how to manipulate them
as we go along. At this point, however, I will just make these
points.

There are at least three different number systems used in the computing
world. These are:-

- Decimal System
- Binary System
- Hexadecimal System

There is @{B}absolutely no need,@{UB} at this stage, for the beginner to know
anything about Binary and Hexadecimal. (I will assume that you know
about decimal numbers?!!?!?) However, if you want to know more at
this stage, just click on @{"Number Systems" LINK "ARB:Misc/Glossary/Number_Systems"} read about them. Or leave
it until a later time.

ARexx will sometimes display the results of an evaluation as an @{"INTEGER" LINK "ARB:Misc/Glossary/Integer_Numbers"}
number, or in @{"SCIENTIFIC or ENGINEERING Notations" LINK "ARB:Misc/Glossary/Number_Notations"}.

Just double click on one of the highlighted areas above to read more
about these types of numbers.

Although beginners would not normally have to worry about these at
all, you should know that, if an evaluation results in a number larger
than 999999999 or less than 0.0000000001 then the result will be
displayed in scientific or engineering notation. For example:-

  The number 1234567890 would be displayed as 1.23456789E+9

However, I doubt if the average ARexx program would ever use numbers
outside this range!


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@NODE "Strings" "ARexx For Beginners - Article 4 - Strings"

@{B}@{U}@{JCENTER}STRINGS@{UB}@{UU}
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A @{"STRING" LINK "ARB:Misc/Glossary/Strings"} is a single unit of data that contains one or more characters
and that has been enclosed in string @{"delimiters" LINK "ARB:Misc/Glossary/Strings"15}.

Strings are heavily used and referred to in ARexx so just double
click on the above highlighted area to read more about them.

We will learn, as we go along, a lot about how to manipulate strings
and how to get the user to enter them from the keyboard so that we
can store them as data.


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