CODEWITHSUNDEEP
delphidelphi-7dynamic-arrays
Keaton Pennells
Keaton Pennells

Reputation: 199

How to get minimum and maximum values of a dynamic integer array?

How can I find out the minimum and maximum values of a certain dynamic array defined by array of Integer ?

ex:

Y: array of integer;

Upvotes: 4

Views: 22044

Answers (4)

GrandmasterB
GrandmasterB

Reputation: 3455

It can be done in a single loop...

function ArrayValRange( somearray: array of integer; var minval: integer; var maxval: integer): boolean;
var
   i: integer;
begin
  result := false;
  if length( somearray) < 1 then
      exit;
  result := true;

  maxval = somearray[ Low(somearray)];
  minval = maxval;

  for i := Low(somearray)+1 to High(somearray) do
  begin
    if somearray[i] > maxval then
      maxval := somearray[i];

    if somearray[i] < minval then
      minval := somearray[i];

  end;
end;

then

if ArrayValRange( myarray, min, max) then
begin
   //do your thing
end;

Upvotes: 3

David Heffernan
David Heffernan

Reputation: 613282

The easiest way is to use the built-in functions that perform this service. They are called MinIntValue and MaxIntValue and can be found in the Math unit.

uses
  Math;
....
TheMin := MinIntValue(TheArray);
TheMax := MaxIntValue(TheArray);

Upvotes: 18

Gloegg
Gloegg

Reputation: 380

There are overloaded functions for this in the unit Math:

function MinValue(const Data: array of Single): Single; overload;
function MinValue(const Data: array of Double): Double; overload;
function MinValue(const Data: array of Extended): Extended; overload;
function MinIntValue(const Data: array of Integer): Integer;

function MaxValue(const Data: array of Single): Single; overload;
function MaxValue(const Data: array of Double): Double; overload;
function MaxValue(const Data: array of Extended): Extended; overload;
function MaxIntValue(const Data: array of Integer): Integer;

since you are using integers you should use MinIntValue and MaxIntValue

Upvotes: 11

Remy Lebeau
Remy Lebeau

Reputation: 597111

You have to loop through the array, looking for the desired values, eg:

function TMyClass.GetMinValue: Integer;
var
  Idx: Integer;
begin
  Result := MyArray[Low(MyArray)];
  for Idx := Low(MyArray)+1 to High(MyArray) do
  begin
    if MyArray[Idx] < Result then
      Result := MyArray[Idx];
  end;
end;

function TMyClass.GetMaxValue: Integer;
var
  Idx: Integer;
begin
  Result := MyArray[Low(MyArray)];
  for Idx := Low(MyArray)+1 to High(MyArray) do
  begin
    if MyArray[Idx] > Result then
      Result := MyArray[Idx];
  end;
end;

Upvotes: 5

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