---
title: ConverterBase
summary: API reference for ConverterBase.
status: draft
owner: <owner>
last_reviewed: 2026-07-23
library: SAIF.Framework.BaseN
reference_type: package
---

# ConverterBase

`ConverterBase` is the abstract (`MustInherit`) template implementation of `IConverter`. It supplies default digit-conversion and formatting logic that concrete converters (`BinaryConverter`, `OctalConverter`, `HexConverter`, `ExcelConverter`) override only where their base's behavior differs.

## Purpose
- Provide reusable default implementations of `IConverter`'s conversion and formatting members so concrete converters only need to override base-specific behavior.

## Context
- Namespace: `SAIF.Framework.BaseN`
- Assembly/package: `SAIF.Framework.BaseN` (also bundled into the `SAIF.BOF.Framework` NuGet package)

## Public members
| Member | Signature | Purpose |
| --- | --- | --- |
| `Base` | `Public MustOverride ReadOnly Property Base() As Integer` | Abstract; concrete subclasses must supply the numeric base. |
| `ConvertAlphaToNumeric` | `Public Overridable Function ConvertAlphaToNumeric(ByVal input As String) As Integer` | Default: returns `CInt(input)` if `IsNumeric(input)` is `True`; otherwise returns `0` ([BR-004](../../business-rules.md#br-004-non-numeric-input-to-the-default-alpha-to-numeric-conversion-is-treated-as-zero)). |
| `ConvertNumericToAlpha` | `Public Overridable Function ConvertNumericToAlpha(ByVal input As Integer) As String` | Default: returns `input.ToString()`. |
| `FormatBaseN` | `Public Overridable Function FormatBaseN(ByVal values As Integer()) As String` | Default: iterates the digit array right-to-left, converting each digit via `ConvertNumericToAlpha` and concatenating the results. |

## Behavioral notes
- `ConvertAlphaToNumeric`'s silent-zero-on-non-numeric-input behavior is relied upon by `BinaryConverter` and `OctalConverter`, which do not override this member ([BR-004](../../business-rules.md#br-004-non-numeric-input-to-the-default-alpha-to-numeric-conversion-is-treated-as-zero)).
- All three members are declared `Overridable`, allowing subclasses to selectively override only the behavior that differs for their base (e.g., `HexConverter` and `ExcelConverter` override all three; `BinaryConverter`/`OctalConverter` override none).

## Constraints and usage notes
- `ConverterBase` cannot be instantiated directly (`MustInherit`); it must be subclassed to provide a concrete `Base` value.

> **Note:** Statements marked with * were inferred from code structure, naming conventions, or
> contextual evidence where direct confirmation was not available in source artifacts. Statements
> marked with ** could not be confirmed; treat as unknown until verified. Statements marked with
> † were retrieved from dependency library documentation via the Legends CLI RAG service. They
> describe inherited behavior from the indicated origin library and should be verified if the
> dependency version changes.

## Sources
- `SAIF.Framework.BaseN\ConverterBase.vb`