$ERROR: Difference between revisions

Revision as of 22:29, 31 January 2023

The $ERROR metacommand triggers a compilation error.

$ERROR message

This metacommand does not require a comment ' or REM before it.
message is any text. Quotation marks are not required.
When QB64 tries to compile an $ERROR metacommand a compilation error is triggered and message is shown to the user. This is useful in $IF blocks.
If there is a particular situation where you know your program will not work properly, you can prevent the user compiling and give them a helpful error message instead by checking for the condition with $IF.
An $ERROR directive not inside an conditional $IF (or $ELSEIF) block is useless because the program will never compile in that case.

$IF VERSION < 2.1 OR WINDOWS = 0 THEN
    $ERROR Requires Windows QB64 version 2.1 or above
$END IF

Output (IDE Status Area): Compilation check failed: REQUIRES WINDOWS QB64 VERSION 2.1 OR ABOVE on line 2 (assuming your version of QB64 doesn't meet those requirements).

@@ Line 10: / Line 10: @@
 * {{Parameter|message}} is any text. Quotation marks are not required.
 * When QB64 tries to compile an '''$ERROR''' metacommand a compilation error is triggered and {{Parameter|message}} is shown to the user. This is useful in [[$IF]] blocks.
-{{PageDescription}}
 * If there is a particular situation where you know your program will not work properly, you can prevent the user compiling and give them a helpful error message instead by checking for the condition with [[$IF]].
 * An '''$ERROR''' directive not inside an conditional [[$IF]] (or [[$ELSEIF]]) block is useless because the program will '''never''' compile in that case.