=====Data without DATA=====

//By JGH, May-2006.//\\  It is common for programs to put commonly used data in **DATA** statements which are then read into a set a variables at startup. A classic example is the names of months:\\ 
<code bb4w>
        DIM mon$(12)
        RESTORE
        FOR mon%=1 TO 12:READ mon$(mon%):NEXT mon%
        DATA Jan,Feb,Mar,Apr,May,Jun,Jul,Aug,Sep,Oct,Nov,Dec
</code>
This has a few immediate disadvantages:\\ 

  * The data is held in memory //twice//, in the program itself, and in **mon$()**
  * The **DATA** pointer is modified, unless **LOCAL**ised
\\  You can avoid the **DATA** pointer being modified by doing the following:\\ \\ 
<code bb4w>
        DIM mon$(12)
        mon$() = "","Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"
</code>
but the data is still held in memory twice.\\ \\  An alternative for small bits of fixed data like this is to hold them in a string:\\ 
<code bb4w>
        DEF FNmon(mon%)=MID$("JanFebMarAprMayJunJulAugSepOctNovDec",mon%*3-2,3)
</code>
This has several advantages:\\ 

  * The data string only occurs in the memory once
  * The **DATA** pointer is not affected
\\  This can even be done for data that at first sight doesn't look like fixed data:\\ 
<code bb4w>
        DEF FNmonth(mon%) \
        \ =MID$("JanuaryFebruaryMarchAprilMayJuneJulyAugustSeptemberOctoberNovemberDecember", \
        \ VALMID$("010816212629333743525967",mon%*2-1,2), \
        \ VALMID$("785534469788",mon%,1))
</code>
The first **VALMID$** string is a series of initial start positions of the month name strings for each month. The second **VALMID$** string is the length of each month name.\\ \\  Note: the example functions only give valid results for valid month numbers.