# casing statement

The casing statement toggles case sensitivity
relative to input data and string comparisons in the current program
and any called subroutines.

## Syntax

```
casing [on|off|exp]
```

## Parameter(s)

| on | Enables case sensitivity. |
| --- | --- |
| off | Disables case sensitivity. |
| exp | Casing is turned on if the expression evaluates to nonzero (true) and turned off if it evaluates to 0 (false). |

## Description

The FlashBASIC or BASIC casing
flag is automatically initialized to the case setting at TCL (which
can be set using the TCL case command).

With casing on, the strings `"quit"`, `"Quit"`, and `"QUIT"` are treated
as three different strings of characters. With casing off they are all treated as the same string.

See system(27) and system(28) in [system() function](https://d3codex.com/pickbasic-flashbasic/system-function/) for the ability to interrogate the current status of case sensitivity.

This is not to be confused with the functionality of the TCL basic command, which is case sensitive, or the TCL compile command, which is not case sensitive with respect
to statement keywords and variable names.

## Example(s)

Entering `"quit"` causes the program to display lowercase. Any uppercase character
in input, such as `"Quit"`, causes the program to display `"upper case"`.

```
casing on
crt "enter quit " :
input quit
if quit = "quit" then crt "lower case" end else crt "upper case"
```

## See also

- [basic command](https://d3codex.com/tcl/basic-command/)
- [case command](https://d3codex.com/tcl/case-command/)
- [d (date) processing code](https://d3codex.com/processingcodes/d-date-processing-code/)
- [Statements and functions](https://d3codex.com/pickbasic-flashbasic/statements-and-functions/)
- [Substring expressions](https://d3codex.com/pickbasic-flashbasic/substring-expressions/)
- [Substring expressions](https://d3codex.com/pickbasic-flashbasic/substring-expressions/)
- [Substring expressions](https://d3codex.com/pickbasic-flashbasic/substring-expressions/)
- [Substring expressions](https://d3codex.com/pickbasic-flashbasic/substring-expressions/)
- [system() function](https://d3codex.com/pickbasic-flashbasic/system-function/)
- [\ arithmetic operator](https://d3codex.com/pickbasic-flashbasic/backslash-arithmetic-operator/)

---
Source: https://d3codex.com/pickbasic-flashbasic/casing-statement/ - part of the D3Codex reference.