Entry

BBCBASIC: Windows: Array: Function: How to pass an array to a function?

Feb 2nd, 2006 17:29
Knud van Eeden,

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--- Knud van Eeden --- 02 February 2021 - 11:54 pm -------------------
BBCBASIC: Windows: Array: Function: How to pass an array to a function?
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There are at least 2 methods possible.
 1. -Using string concatenation and the EVAL function
 2. -Using the native BBCBASIC for Windows array passing method
===
Conclusion:
 The string concatenation method is more general than the other method,
 but is certainly much slower, because the string has to be 
concatenated
 and the EVAL function has to be called to evaluate the array value out
 of the string.
===
Method: Using string concatenation and EVAL
Example shows passing a 1 dimensional array:
 1. -Create the following program
--- cut here: begin --------------------------------------------------
 minI% = 1
 maxI% = 5
 I% = 0
 :
 DIM xR( maxI% )
 :
 FOR I% = minI% TO maxI%
   READ xR( I% )
 NEXT I%
 :
 PRINT "maximum = "; FNArrayGetMaximumR( minI%, maxI%, "xR(", ")" )
 :
 END
 :
 :
 :
 REM library: determine the maximum
 DEF FNArrayGetMaximumR( minI%, maxI%, arrayBegin$, arrayEnd$ )
 LOCAL maxR
 LOCAL xR
 maxR = EVAL( arrayBegin$ + STR$( minI% ) + arrayEnd$ ) : REM set 
maximum at first equal to first element
 :
 FOR I% = minI% TO maxI%
   xR = EVAL( arrayBegin$ + STR$( I% ) + arrayEnd$ )
   IF xR > maxR THEN maxR = xR
 NEXT I%
 = maxR
 :
 DATA 43
 DATA 2
 DATA 789
 DATA 9999
 DATA 6
 :
--- cut here: end ----------------------------------------------------
 2. -If you run this program it will show
      maximum = 9999
===
Example shows passing a 2 dimensional array
 1. -Create the following program
--- cut here: begin --------------------------------------------------
 minI% = 1
 maxI% = 5
 I% = 0
 :
 DIM xR( maxI%, 2 )
 :
 FOR I% = minI% TO maxI%
   READ xR( I%, 1 )
   READ xR( I%, 2 )
 NEXT I%
 :
 PRINT "maximum = "; FNArrayGetMaximumR( minI%, maxI%, "xR(", ", 1 )" )
 :
 END
 :
 :
 :
 REM library: determine the maximum
 DEF FNArrayGetMaximumR( minI%, maxI%, arrayBegin$, arrayEnd$ )
 LOCAL maxR
 LOCAL xR
 maxR = EVAL( arrayBegin$ + STR$( minI% ) + arrayEnd$ ) : REM set 
maximum at first equal to first element
 :
 FOR I% = minI% TO maxI%
   xR = EVAL( arrayBegin$ + STR$( I% ) + arrayEnd$ )
   IF xR > maxR THEN maxR = xR
 NEXT I%
 = maxR
 :
 DATA 43, 43
 DATA 2, 2
 DATA 789, 789
 DATA 9999, 9999
 DATA 6, 6
--- cut here: end ----------------------------------------------------
 2. -If you run this program it will show
      maximum = 9999
===
Example shows passing a 3 dimensional array
 1. -Create the following program
--- cut here: begin --------------------------------------------------
 minI% = 1
 maxI% = 5
 I% = 0
 :
 DIM xR( maxI%, 2, 3 )
 :
 FOR I% = minI% TO maxI%
   READ xR( I%, 1, 1 )
   READ xR( I%, 1, 1 )
 NEXT I%
 :
 PRINT "maximum = "; FNArrayGetMaximumR( minI%, maxI%, "xR(", ", 1, 
1 )" )
 :
 END
 :
 :
 :
 REM library: determine the maximum
 DEF FNArrayGetMaximumR( minI%, maxI%, arrayBegin$, arrayEnd$ )
 LOCAL maxR
 LOCAL xR
 maxR = EVAL( arrayBegin$ + STR$( minI% ) + arrayEnd$ ) : REM set 
maximum at first equal to first element
 :
 FOR I% = minI% TO maxI%
   xR = EVAL( arrayBegin$ + STR$( I% ) + arrayEnd$ )
   IF xR > maxR THEN maxR = xR
 NEXT I%
 = maxR
 :
 DATA 43, 43, 43
 DATA 2, 2, 2
 DATA 789, 789, 789
 DATA 9999, 9999, 9999
 DATA 6, 6, 6
--- cut here: end ----------------------------------------------------
 2. -If you run this program it will show
      maximum = 9999
===
Method: Passing the array using the more specific BBCBASIC for Windows 
method
        (see BBCBASIC for Windows help: search for 'passing')
Example shows passing a 1 dimensional array:
 1. -Create the following program
--- cut here: begin --------------------------------------------------
 minI% = 1
 maxI% = 5
 I% = 0
 :
 DIM xR( maxI% )
 :
 FOR I% = minI% TO maxI%
   READ xR( I% )
 NEXT I%
 :
 PRINT "maximum = "; FNArrayGetMaximumR( xR() )
 :
 END
 :
 :
 :
 REM library: determine the maximum
 DEF FNArrayGetMaximumR( A() )
 LOCAL maxR
 LOCAL xR
 LOCAL minI%
 LOCAL maxI%
 minI% = 1
 maxI% = DIM( A(), 1 )
 :
 maxR = A( minI% ) : REM set maximum at first equal to first element
 :
 FOR I% = minI% TO maxI%
   xR = A( I% )
   IF xR > maxR THEN maxR = xR
 NEXT I%
 = maxR
 :
 DATA 43
 DATA 2
 DATA 789
 DATA 9999
 DATA 6
 :
--- cut here: end ----------------------------------------------------
 2. -If you run this program it will show
      maximum = 9999
===
Example shows passing a 2 dimensional array:
 1. -Create the following program
--- cut here: begin --------------------------------------------------
 minI% = 1
 maxI% = 5
 I% = 0
 :
 DIM xR( maxI%, 1 )
 :
 FOR I% = minI% TO maxI%
   READ xR( I%, 1 ), xR( I%, 1 )
 NEXT I%
 :
 PRINT "maximum = "; FNArrayGetMaximumR( xR(), 1 )
 :
 END
 :
 :
 :
 REM library: determine the maximum
 DEF FNArrayGetMaximumR( A(), columnI% )
 LOCAL maxR
 LOCAL xR
 LOCAL minI%
 LOCAL maxI%
 minI% = 1
 maxI% = DIM( A(), 1 )
 :
 maxR = A( minI%, columnI% ) : REM set maximum at first equal to first 
element
 :
 FOR I% = minI% TO maxI%
   xR = A( I%, columnI% )
   IF xR > maxR THEN maxR = xR
 NEXT I%
 = maxR
 :
 DATA 43, 43
 DATA 2, 2
 DATA 789, 789
 DATA 9999, 9999
 DATA 6, 6
 :
--- cut here: end ----------------------------------------------------
 2. -If you run this program it will show
      maximum = 9999
===
Example shows passing a 3 dimensional array:
 1. -Create the following program
--- cut here: begin --------------------------------------------------
 minI% = 1
 maxI% = 5
 I% = 0
 :
 DIM xR( maxI%, 1, 1 )
 :
 FOR I% = minI% TO maxI%
   READ xR( I%, 1, 1 ), xR( I%, 1, 1 ), xR( I%, 1, 1 )
 NEXT I%
 :
 PRINT "maximum = "; FNArrayGetMaximumR( xR(), 1, 1 )
 :
 END
 :
 :
 :
 REM library: determine the maximum
 DEF FNArrayGetMaximumR( A(), columnI%, depthI% )
 LOCAL maxR
 LOCAL xR
 LOCAL minI%
 LOCAL maxI%
 minI% = 1
 maxI% = DIM( A(), 1 )
 :
 maxR = A( minI%, columnI%, depthI% ) : REM set maximum at first equal 
to first element
 :
 FOR I% = minI% TO maxI%
   xR = A( I%, columnI%, depthI% )
   IF xR > maxR THEN maxR = xR
 NEXT I%
 = maxR
 :
 DATA 43, 43, 43
 DATA 2, 2, 2
 DATA 789, 789, 789
 DATA 9999, 9999, 9999
 DATA 6, 6, 6
 :
--- cut here: end ----------------------------------------------------
 2. -If you run this program it will show
      maximum = 9999
---
---
Internet: see also:
---
BBCBASIC: Windows: Array: Minimum: How to determine the minimum value 
of an array?
http://www.faqts.com/knowledge_base/view.phtml/aid/39451/fid/768
---
BBCBASIC: Windows: Array: Maximum: How to determine the maximum value 
of an array?
http://www.faqts.com/knowledge_base/view.phtml/aid/39447/fid/768
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