Floppyshop 2/Floppyshop - 2.zip/Floppyshop - 2.iso/diskmags/3565-4.665/dmg-4180/a/a13.doc

Text File | 1987-04-21 | 5KB | 195 lines

          UNDERSTANDING STOS
     Copied from the STOS Magazine
  Thanks to Dion Guy who retains the
      Copyright to this Article

Here is the  final  part  of  our  A-Z
variable guide (see issues 1+2).We also
have a bit more on using  variables  in
your  programs.

SGN(num var)
  SGN  is used to find the  SIGN  of a
number.The result will equal -1 if the
number is negative,0 if the  number is
zero and 1 if the number is positive.Eg
 {A=10:print SGN (A)} will display 1 as
a result.

SORTdimensioned var or num var(startpos)
  SORT can sort through your array  and
put  the contents into  ascending order
for   you.   It  does  this  relatively
fast.For example if you  have  an array
of 10  numbers,say NUM,that you  wanted
to sort into ascending order you  would
just use-sort NUM(0). The number in the
brackets  indicates  the  place  in the
array to start sorting from(usually 0).
Type in this program to see sort in use.

10 dim NUM (10)
20 for A=1 to 10
30 B=rnd(100)
40 NUM(A)=B
50 next A
60 sort NUM(0)
70 for A=1 to 10
80 print NUM (A)
90 next A
100 end

  This  program  will  pick ten  random
numbers from between 1 and 100 and
store them in the NUM array. We then use
the sort command to sort  these  random
numbers into ascending order. Lastly we
print  the numbers so you can see  sort
has done its job.SORT is mainly used in
conjunction with MATCH which allows you
to find the closest match to a
specified variable within an array.
See MATCH for further details.

SPACE$(number of spaces)
  This  is a reserved  variable  which
allows you to add spaces to a string
 or display spaces on screen. Eg :
10 print "Hello";SPACE$(5);"there"
or
10 A$="Hello"
20 A$=A$+space$(5):A$=A$+"there"
30 print A$

STR$ (num var)
  STR$  converts a number to  a string.
This  is useful for using  the `centre`
command as centre does not allow you to
display number variables etc. Eg:
10 A=4
20 home:centre " STOS  Magazine  issue"
 +str$(A)+" is  here !"
or another use:
10 A=68000
20 print A
30 A$= str$(A):print A$
 The opposite,VAL,allows you to convert
a string to a number. See VAL.

STRING$ (var,length)
 STRING$ can be used to create a string,
length    characters    long,containing
nothing  but the first character of the
specified     string.      Eg:    print
STRING$("HAT",10) -will display 10 H's.

SWAP (var/num var,var/num var)
  This simply SWAPs the  information of
two  variables(of the same type)around.
Eg :
10 A=10:B=20
20 swap A,B
30 print A,B

TIME$
  TIME$  is a string that  STOS updates
every 50th of a second,and contains how
long ,in hours,minutes and seconds that
STOS  has been running.  The  format of
this variable is"hours:minutes:seconds"
and  can be set with a command such as:
TIME$="01:20:30".  This  would  set the
clock  to  1  hour,20  minutes  and  30
seconds.

TIMER
  TIMER  is another variable  that STOS
updates  every  50th  of  a  second,and
represents   how  long  STOS  has  been
running.  The  format is different from
TIME$ though as this contains the
actual 50th's of a second STOS has been
running.  Eg - if STOS has been running
for 2 minutes,  TIMER would contain the
number 6000. You can alter TIMER in the
same  way  as you can alter  any  other
number  variable.  Eg  - TIMER=0.  This
reserved  variable can be used  to time
program execution times,program loops
or can be used as an in game/program
timer.

TRUE
  TRUE  is basically a  number variable
that always contains the number -1. The
TRUE   command  can  be  used  to  make
decisions as to whether things are true
or false. Eg :
10  A=10:if A>0=TRUE then print "{A} is
higher than zero"
See FALSE

UPPER$
  UPPER$ is used to display a string in
upper case letters,even if the string
is in lower case letters.  Eg  -  print
UPPER$("lower") -will display `LOWER `.
Another example:
10 A$="Hello"
20 A$=upper$(a$)
30 print A$
See LOWER$

VAL(var)
 VAL is used to convert a string into a
number variable. Eg :
10 A$="10"
20 A=VAL(A$)
30 print A
See STR$

XGRAPHIC(num var)
  This  command  is very  useful  as it
converts  a X text coordinate into a  X
graphic   coordinate.    Eg   -   print
XGRAPHIC(2)  {from  the  standard  STOS
editor  window} - will return  16. This
command   {and  YGRAPHIC}   takes  into
account if you are in a window.
See YGRAPHIC

XMOUSE
  XMOUSE  is a reserved  variable which
holds  the  X  position  of  the  mouse
cursor. Eg - {print XMOUSE}.See YMOUSE

XTEXT(num var)
  XTEXT is the opposite of  XGRAPHIC in
that it converts Xgraphic coordinations
into  X  text coordinates.  Eg  - print
XTEXT(16){from the standard STOS editor
window}  - will return 2.  This command
{and  YTEXT} takes into account if  you
are in a window. See YTEXT

YGRAPHIC(num var)
   The   Y  coordinate   equivalent  of
XGRAPHIC. See XGRAPHIC.

YMOUSE
 The Y coordinate equivalent of XMOUSE.
See XMOUSE

YTEXT(num var)
  The Y coordinate equivalent of XTEXT.
See XTEXT.