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Discounted

Function Discounted( aValue, aDiscPC : Extended) : Extended

Example​

procedure ScriptEvent(var Value: Variant);
begin
  Value := Discounted(250, 12.5); // 218.75
end;

Usage​

Discounted calculates the unrounded value remaining after applying a percentage discount.

Parameters

NameTypeDescription
aValueExtendedBase value to discount.
aDiscPCExtendedDiscount rate expressed as a percentage; for example, 12.5 means 12.5%.

Returns

An Extended result equal to aValue - (aValue * (aDiscPC / 100)). The result is not rounded.

Behaviour

A zero rate returns the original value. A 100% rate returns zero. The function does not change either input or any map state.

Errors

There is no explicit range validation or local exception handler. Arithmetic failures raised by the runtime propagate to the calling script.

Usage notes

Use DiscountAmount if the mapping needs the amount removed rather than the remaining value. Round only according to the destination system's documented monetary rule.

Additional Technical Info​

Discounted returns the value remaining after subtracting a percentage discount from the supplied base value.

Implementation

The scripting import registers the Velox function directly. Its terminal implementation calculates the percentage amount and subtracts that amount from aValue; it does not delegate to DiscountAmount or a currency library.

Edge cases and quirks

  • The rate is supplied in percentage points, so 10 means 10%.
  • A negative rate increases the value. A rate above 100% produces a result with the opposite sign to a positive base.
  • Negative base values are processed by the same formula; the function does not interpret debit, credit or reversal semantics.
  • The use of binary floating-point Extended arithmetic can leave small representation differences. No currency rounding is performed, and Delphi's Extended representation varies by platform.

Performance and concurrency

The function takes constant time, allocates no memory and reads no shared state. It is re-entrant subject to the runtime floating-point environment.

Related entries

External references

Created 2026-07-15