Description
int assert (string|bool assertion)
assert() will check the given
assertion and take appropriate
action if its result is false.
If the assertion is given as a string it
will be evaluated as PHP code by assert().
The advantages of a string assertion
are less overhead when assertion checking is off and messages
containing the assertion expression when
an assertion failes.
Assertion should be used as a debugging feature only. You may
use them for sanity-checks that test for conditions that should
always be true and that indicate some programming errors if not
or to check for the presence of certain features like extension
functions or certain system limits and features.
Assertions should not be used for normal runtime operations
like input parameter checks. As a rule of thumb your code
should always be able to work correct if assertion checking
is not activated.
The behavior of assert() may be configured
by assert_options() or by .ini-settings
described in that functions manual page.
PHP options/info