how to fill a stringgrid in delphi between two given numbers

Question

My assignment

Fill the given matrices/”stringgrids” M1 and M2 with random numbers drawn from [FROM, TO], where FROM and TO should be read from the given Edit-fields.

I'm struggling to generate random numbers between the values given by the user. Here's what I have:

procedure FillGridRandom(var S:TStringGrid); 
var 
  i ,j :integer; //local variables
  A,B:array of array of integer; 
  val1,val2 :integer; 
begin 
  val1 := StrToInt(Form1.Edit1.Text);
  val2 := StrToInt(Form1.Edit2.Text);
  setlength(A,10,10);
  setlength(B,10,8); 
  for i := 0 to s.colcount do begin
    for j := 0 to s.rowcount do begin 
      A[i][j]:= random;
    end; 
  end;
end;

Answer 1

How do I generate a random number between the values given by the user?

The Random function has two overloads. The variant with no parameters returns real values between 0 and 1. The other variant accepts an integer parameter N and returns integers i such that 0 <= i < N. So you can use some arithmetic to produce values in the range a to b.

function RandInRange(const a, b: Integer): Integer;
begin
  Result := a + Random(b-a+1);
end;

This returns integers i that satisfy a <= i <= b and that are uniformly distributed. Well, the distribution is only as good as the underlying PRNG used by Random.

Note that I've made no attempt to check or enforce that a <= b.

Alternatively, as is pointed out in the comments, you could use RandomRange from the Maths unit. Although to beware that it has a different convention and returns values in the range a <= i < b.

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Looking at the rest of your code, you should not use a var parameter to pass the string grid reference. You are not going to change the reference. You might call methods on the string grid, or access properties, but you are not going to modify the reference.

And as for that string grid, you do not do anything with it. You populate an array which you immediately throw away. You will need to assign to the elements of the string grid. The arrays are pointless and can be removed.