warning warning messages

## Syntax

                warning('string')
                warning(string_matrix)
                warning('off')
                warning('on')
                warning('stop')
                mode = warning('query')

## Description

`warning('string')` prints the character string `'string'` in a warning message.

`warning(string_matrix)` prints each element of the matrix `string_matrix` in a warning message.

`'on'` enables warning messages. Warning messages do not interrupt script execution.

`'off'` disables warning messages, warning messages are ignored (neither displayed nor interrupting script execution).

`'stop'` enables warning messages and stops execution when a warning is encountered.

`'query'` gets state `'on'`, `'off'` or `'stop'`.

`warning("on")`, `warning("off")` and `warning("stop")` also affect hard-coded functions issuing warnings.

## Examples

    warning_prev = warning("query"); // remembering the initial warning status

    warning('on')
    warning('this is a warning')
    warning('off')
    warning('this is a warning')
    warning('query')
    warning('on')
    // Example with a localized message
    warning(msprintf(gettext("%s: Wrong number of input argument: %d expected.\n"),"myFunction",2));

    // Setting warning stop
    warning("stop")

    try
        warning("this is a warning");
    catch
        lasterror() // Warning message is considered an error
    end

    warning(warning_prev); // restoring the initial warning status

## See also

- error
- gettext
- msprintf
- messagebox

## History

6.0 `"stop"` option added.