Delphi动态数组

Question

I'm using Delphi 10.0 Seattle.

Suppose I have a record like this:

TmyRecord = record
  a,b : string;
  ar  : array of string
end;

And a variable like this:

v : array of TmyRecord;

and some code like this:

SetLength(v,2);
SetLength(v[0].ar,3);
SetLength(v[1].ar,2);
SetLength(v[0].ar[0],10);
SetLength(v[0].ar[1],5);
SetLength(v[0].ar[2],7);
...
v[0].ar[0][0] := 'aaaa';
v[0].ar[0][1] := 'bbbb';
....
v[1].ar[1][0] := 'xxxx';

Will this statement:

SetLength(v,0);

free all of the occupied memory, or do I have to free it manually?

Answer 1

Dynamic array memory is automatically managed by Delphi and is released when they go out of scope.

Clearing v array will automatically release all memory including the ones occupied by ar member of your record.

You don't have to do anything else.

You can also clear v array by setting it to nil

v := nil;

or by using the intrinsic Finalize :

Finalize(v);

All of these have identical meaning.