music

# operators

## summary

This section looks at operators.

## free computer programming text book project

If you like the idea of this project,

### stub section

This subchapter is a stub section. It will be filled in with instructional material later. For now it serves the purpose of a place holder for the order of instruction.

Professors are invited to give feedback on both the proposed contents and the propsed order of this text book. Send commentary to Milo, PO Box 1361, Tustin, California, 92781, USA.

# operators

This section looks at operators.

Operators (such as the plus sign for addition) are a convenience for the programmer. Everything an operator does could be done with key words or functions (depending ont eh design choices made by the creator of a programming language).

Some languages have a very rich set of operators and there are some languages that have no operators at all.

The choice of operators provided by a language greatly influences how a programmer thinks and programs in that particular language.

## JOVIAL

The following material is from the unclassified Computer Programming Manual for the JOVIAL (J73) Language, RADC-TR-81-143, Final Technical Report of June 1981.

1.1.4 Operators

The operations provided by JOVIAL reflect the applications of the
language; they determine what the language can and cannot do.
Thus JOVIAL is strong in numerical calculation and control logic,
but has minimal operations for text processing.

JOVIAL does not have any operations for input-output or file
maintenance because it is assumed that a JOVIAL program runs in a
relatively specialized environment that provides subroutines for
those operations.

Some of the operations of JOVIAL are represented by operators,
others by built-in functions.

Chapter 1 Introduction, page 7

The JOVIAL operators are summarized in the following table:

Type          Operators       Operation

Arithmetic    +   -           prefix signs
**              exponentiate
*   /   MOD     multiply, divide, and modulus
+   -           infix add and subtract

Relational    <   >   =       less than, greater than, equal
<=  >=  <>      less than or equal,
greater or equal, not equal

Logical       NOT             (prefix) "not"
AND   OR        "and", "or"
XOR   EQV       "exclusive or", "equivalent"

An arithmetic operator takes integer, float, or fixed values as
its operands and produces an integer, gloat, fixed value as its
result.  Type classes cannot be mixed.  For example, a fixed
value cannot be added to a float value unless one is explicitly
converted to the type of the other.

A relational operator compares any two values of the same type
and produces a Boolean value as its result.  A logical operator
takes bit-string values and also produces a Boolean result.  (A
Boolean value is a one-bit bit-string, representing "true" or
"false", depending on whether it is one or zero.)

The JOVIAL operators are described in detail in Chapter 11,
where, for example, you will find the rules for operations on
fixed values and for the comparison of such objects as
character-strings and pointers.

Chapter 1 Introduction, page 8

# free music player coding example

Coding example: I am making heavily documented and explained open source code for a method to play music for free — almost any song, no subscription fees, no download costs, no advertisements, all completely legal. This is done by building a front-end to YouTube (which checks the copyright permissions for you).

View music player in action: www.musicinpublic.com/.

Create your own copy from the original source code/ (presented for learning programming).

## view text bookHTML file

Because I no longer have the computer and software to make PDFs, the book is available as an HTML file, which you can convert into a PDF.

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## free computer programming text book project

Building a free downloadable text book on computer programming for university, college, community college, and high school classes in computer programming.

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PO Box 1361
Tustin, California 92781

Supporting the entire project:

If you have a business or organization that can support the entire cost of this project, please contact Pr Ntr Kmt (my church)

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