Delphi Basics : Dispose command

DelphiBasics

Dispose
Procedure

Dispose of storage used by a pointer type variable

System unit

1	procedure Dispose(var VariablePointer Pointer-Type);
2	procedure Dispose (var ObjectPointer Object-Pointer; Destructor;

Description

The Dispose procedure comes in two flavours.

The older version is an obsolete method of destroying objects (you should now call the class destructor instead).

The first version frees storage used by a pointer type variable VariablePointer.

You should use Dispose when no longer using a variable allocated using New.

Notes

Warning : the variable is undefined after calling Dispose. It is not set to nil.

Related commands

FreeMem		Free memory storage used by a variable
GetMem		Get a specified number of storage bytes
New		Create a new pointer type variable
ReallocMem		Reallocate an existing block of storage

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Example code : Allocate memory for a record, assign to it, and then dispose of it

type
  TCustomer = Record
    name : string[20];
    age  : Byte;
  end;

var
  custRecPtr : ^TCustomer;

begin
  // Create a customer record using 'New'
  New(custRecptr);

  // Assign values to it
  custRecPtr.name := 'Her indoors';
  custRecPtr.age  := 55;

  // Now display these values
  ShowMessageFmt('%s is %d',[custRecPtr.name, custRecPtr.age]);

  // Now dispose of this allocated record
  Dispose(custRecPtr);
end;

Show full unit code

Her indoors is 55