---
title: Sentence-case a string
summary: Normalizes a string for sentence-style display.
status: draft
owner: SAIF Documentation Generator
last_reviewed: 2026-08-21
library: SAIF.Business.Utilities
reference_type: embedded
operation_id: op-04-sentence-case
trigger: Caller normalizes a string for sentence-style display
---

# Sentence-case a string

Normalizes a string to sentence case: first character upper case, remainder lower case.

| Field | Value |
| --- | --- |
| **Operation ID** | op-04-sentence-case |
| **Trigger** | Caller normalizes a string for sentence-style display |
| **Inputs** | String value |
| **Outputs** | Sentence-cased string |
| **Primary components** | `mdlTextConversion.ToSentenceCase` |
| **Entry point** | SAIF.Business.Utilities/mdlTextConversion.vb |

## Steps

1. Return `Nothing` when the target is `Nothing`.
2. Return the value unchanged when length is 0.
3. Upper-case it when length is 1.
4. Otherwise upper-case the first character and lower-case the remainder ([BR-017](../business-rules.md#br-017-sentence-case-normalization)).

## Process flow

The following diagram visualizes this operation's control flow.

```mermaid
flowchart TD
	Start([Caller invokes ToSentenceCase]) --> CheckNothing{Target is Nothing?}
	CheckNothing -->|Yes| ReturnNothing([Return Nothing])
	CheckNothing -->|No| CheckLen0{Length = 0?}
	CheckLen0 -->|Yes| ReturnUnchanged([Return value unchanged])
	CheckLen0 -->|No| CheckLen1{Length = 1?}
	CheckLen1 -->|Yes| UpperOnly([Upper-case the character])
	CheckLen1 -->|No| UpperFirst["Upper-case first character,<br>lower-case remainder"]
	ReturnNothing --> Done([Return result])
	ReturnUnchanged --> Done
	UpperOnly --> Done
	UpperFirst --> Done
```

## Failure and edge-case behavior
- No exceptions are raised. `Nothing` input returns `Nothing`, zero-length input is returned unchanged, and single-character input is upper-cased without lower-casing any remainder.

## Related documentation
- [Operations and processes](../operations-processes.md)
- [Business rules](../business-rules.md)

## Sources
- `SAIF.Business.Utilities/mdlTextConversion.vb`