Debugging macro that halts program execution if an expression is evaluated to
0 (false).
Syntax
Usage
Assert( expression )
Parameters
expression
Any valid conditional/numeric expression. If expression evaluates to 0 (i.e. "false"), execution is halted.
Description
The
Assert macro is intended for use in debugging and works only if the
-g or
-eassert option is specified on the fbc
command line. In this case it prints an error message and stops the program execution if expression evaluates to 0
.
Its normal use is to check the correct value of the variables or expressions during debugging.
If -g and -eassert are not passed to fbc, the macro does not generate any code, and has no effect.
Note: If an
Assert fails while the program is in a graphics
Screen, the error message will not be visible as it will be printed to the graphics screen, which will be closed immediately after.
Example
Sub foo
Dim a As Integer
a=0
Assert(a=1)
End Sub
foo
'' If -g or -eassert is used, this code stops with: test.bas(3): assertion failed at FOO: a=1
Dialect Differences
- Not available in the -lang qb dialect unless referenced with the alias __ASSERT.
Differences from QB
See also