MOD: Difference between revisions

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(Created page with "The MOD operator gives the remainder after division of one number by another (sometimes called modulus). {{PageSyntax}} : {{Parameter|remainder}} = {{Parameter|numerator}} MOD {{Parameter|divisor}} {{Parameters}} * Returns the integer division remainder as a whole INTEGER, LONG or _INTEGER64 value. * {{Parameter|numerator}} is the INTEGER value to divide. * {{Parameter|divisor}} is the INTEGER value to divide by. {{PageDescription}} * F...")
 
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{{Parameters}}
{{PageParameters}}
* Returns the integer division remainder as a whole [[INTEGER]], [[LONG]] or [[_INTEGER64]] value.
* Returns the integer division remainder as a whole [[INTEGER]], [[LONG]] or [[_INTEGER64]] value.
* {{Parameter|numerator}} is the [[INTEGER]] value to divide.  
* {{Parameter|numerator}} is the [[INTEGER]] value to divide.
* {{Parameter|divisor}} is the [[INTEGER]] value to divide by.
* {{Parameter|divisor}} is the [[INTEGER]] value to divide by.


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{{PageDescription}}
{{PageDescription}}
* Floating decimal point ''numerator'' and ''divisor'' values are [[CINT]] rounded (e.g. {{InlineCode}}19 MOD 6.7{{InlineCodeEnd}} returns 5 just like {{InlineCode}}19 MOD 7{{InlineCodeEnd}} would).
* Floating decimal point ''numerator'' and ''divisor'' values are [[CINT]] rounded (e.g. {{InlineCode}}19 MOD 6.7{{InlineCodeEnd}} returns 5 just like {{InlineCode}}19 MOD 7{{InlineCodeEnd}} would).
* MOD returns 0 if a number is evenly divisible by integer division ( [[\]] ) or the number divided is 0.
* MOD returns 0 if a number is evenly divisible by integer division ( [[\]] ) or the number divided is 0.
* '''{{Parameter|divisor}} (second value) must not be between 0 and .5'''. This will create a [[ERROR Codes|"Division by zero" error]] due to [[CINT]] rounding the value to 0.
* '''{{Parameter|divisor}} (second value) must not be between 0 and .5'''. This will create a [[ERROR Codes|"Division by zero" error]] due to [[CINT]] rounding the value to 0.
* The result has the same sign as the numerator (e.g. {{InlineCode}}-1 MOD 7{{InlineCodeEnd}} returns -1, not 6).
* The result has the same sign as the numerator (e.g. {{InlineCode}}-1 MOD 7{{InlineCodeEnd}} returns -1, not 6).
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{{PageExamples}}
{{PageExamples}}
''Example 1:''  
''Example 1:''
{{CodeStart}}
{{CodeStart}}
   I% = 100 {{Cl|\}} 9  
   I% = 100 {{Cl|\}} 9
   R% = 100 {{Cl|MOD}} 9
   R% = 100 {{Cl|MOD}} 9
   PRINT "Integer division ="; I%, "Remainder ="; R%  
   PRINT "Integer division ="; I%, "Remainder ="; R%
{{CodeEnd}}
{{CodeEnd}}
{{OutputStart}}
{{OutputStart}}
   Integer division = 11        Remainder = 1 '' ''
   Integer division = 11        Remainder = 1
{{OutputEnd}}
{{OutputEnd}}


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LOCATE 7, 20: PRINT USING tmp2$; numerator; divisor; numerator \ divisor
LOCATE 7, 20: PRINT USING tmp2$; numerator; divisor; numerator \ divisor
LOCATE 9, 20: PRINT USING tmp3$; numerator; divisor; numerator MOD divisor
LOCATE 9, 20: PRINT USING tmp3$; numerator; divisor; numerator MOD divisor
DO: SLEEP: LOOP UNTIL INKEY$ <> ""                            
DO: SLEEP: LOOP UNTIL INKEY$ <> ""
NEXT '' ''
NEXT
{{CodeEnd}}
{{CodeEnd}}




''Example 3:'' Integer division and MOD can be used to convert values to different base numbering systems from base 2 to 36 as [[STRING|strings]]:
''Example 3:'' Integer division and MOD can be used to convert values to different base numbering systems from base 2 to 36 as [[STRING|strings]]:
{{CodeStart}} '' ''
{{CodeStart}}
{{Cl|CLS}}
{{Cl|CLS}}
DO
DO
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{{Cl|LOOP}} {{Cl|UNTIL}} num& = 0
{{Cl|LOOP}} {{Cl|UNTIL}} num& = 0
BASEN$ = BN$
BASEN$ = BN$
{{Cl|END FUNCTION}} '' ''
{{Cl|END FUNCTION}}
{{CodeEnd}}
{{CodeEnd}}
: ''Note:'' Base numbering systems over base 10(0 - 9) use alphabetical letters to represent digits greater than 9 like [[&H|Hexadecimal]](0 - F).
: ''Note:'' Base numbering systems over base 10(0 - 9) use alphabetical letters to represent digits greater than 9 like [[&H|Hexadecimal]](0 - F).
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{{PageSeeAlso}}
{{PageSeeAlso}}
* [https://qb64phoenix.com/forum/showthread.php?tid=1196 Featured in our "Keyword of the Day" series]
* [[/|/ (normal division operator)]]
* [[/|/ (normal division operator)]]
* [[\|\ (integer division operator)]]
* [[\|\ (integer division operator)]]

Latest revision as of 17:27, 25 May 2024

The MOD operator gives the remainder after division of one number by another (sometimes called modulus).


Syntax

remainder = numerator MOD divisor


Parameters


Description

  • Floating decimal point numerator and divisor values are CINT rounded (e.g. 19 MOD 6.7 returns 5 just like 19 MOD 7 would).
  • MOD returns 0 if a number is evenly divisible by integer division ( \ ) or the number divided is 0.
  • divisor (second value) must not be between 0 and .5. This will create a "Division by zero" error due to CINT rounding the value to 0.
  • The result has the same sign as the numerator (e.g. -1 MOD 7 returns -1, not 6).
  • Division and multiplication operations are performed before addition and subtraction in QBasic's order of operations.


Examples

Example 1: 

  I% = 100 \ 9
  R% = 100 MOD 9
  PRINT "Integer division ="; I%, "Remainder ="; R%

  Integer division = 11        Remainder = 1

Explanation: Integer division 100 \ 9 returns 11. 11 * 9 = 99. So the remainder must be 1 as 100 - 99 = 1. Normal decimal point division would return 11.11111.


Example 2: Comparing normal, integer and remainder division. 

tmp1$ = " Normal:         ####.# / #### = ##.###   "
tmp2$ = " Integer:        ####.# \ #### = ###      "
tmp3$ = " Remainder:    ####.# MOD #### = ####     "
FOR i = 1 TO 6
   SELECT CASE i
     CASE 1: numerator = 1: divisor = 5
     CASE 2: numerator = 13: divisor = 10
     CASE 3: numerator = 990: divisor = 100
     CASE 4: numerator = 1100: divisor = 100
     CASE 5: numerator = 4501: divisor = 1000
     CASE 6: numerator = 50.6: divisor = 10
   END SELECT
LOCATE 5, 20: PRINT USING tmp1$; numerator; divisor; numerator / divisor
LOCATE 7, 20: PRINT USING tmp2$; numerator; divisor; numerator \ divisor
LOCATE 9, 20: PRINT USING tmp3$; numerator; divisor; numerator MOD divisor
DO: SLEEP: LOOP UNTIL INKEY$ <> ""
NEXT


Example 3: Integer division and MOD can be used to convert values to different base numbering systems from base 2 to 36 as strings: 

CLS
DO
  INPUT "Enter a base number system 2 to 36: ", b%
  IF b% < 2 OR b% > 36 THEN EXIT DO
  PRINT "Enter a positive value to convert: ";
  num$ = ""
  DO: K$ = INKEY$
    num$ = num$ + K$
    LOCATE CSRLIN, POS(0): PRINT K$;
  LOOP UNTIL K$ = CHR$(13)
  n& = VAL(num$)
  IF n& = 0 THEN EXIT DO
  Bnum$ = BASEN$(n&, b%)
  PRINT Bnum$ ', VAL("&H" + Bnum$) 'tests hexadecimal base 16 only
LOOP

END

FUNCTION BASEN$ (number&, basenum%)
IF basenum% < 2 OR basenum% > 36 OR number& = 0 THEN EXIT FUNCTION
num& = number& 'protect value of number!
DO
  remain% = ABS(num&) MOD basenum% ' remainder is used to create actual digit 0 to Z
  num& = num& \ basenum% ' move up one exponent of base% with integer division
  IF remain% > 9 THEN
    b$ = CHR$(65 + (remain% - 10)) 'limited to base 36
  ELSE: b$ = LTRIM$(STR$(remain%)) ' make remainder a string number
  END IF
  BN$ = b$ + BN$ ' add remainder character to base number string
LOOP UNTIL num& = 0
BASEN$ = BN$
END FUNCTION
Note: Base numbering systems over base 10(0 - 9) use alphabetical letters to represent digits greater than 9 like Hexadecimal(0 - F).


See also


Navigation:
Main Page with Articles and Tutorials
Keyword Reference - Alphabetical
Keyword Reference - By usage
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