assert Checks if assertion is &false; &reftitle.description; PHP 5 and 7 boolassert mixedassertion stringdescription PHP 7 boolassert mixedassertion Throwableexception 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. If you pass a boolean condition as assertion, this condition will not be passed as a parameter to the assertion callback which you may have defined with assert_options. Rather, the callback will receive an empty string. Assertions 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 correctly 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. The assert_options function and/or ASSERT_CALLBACK configuration directive allow a callback function to be set to handle failed assertions. assert callbacks are particularly useful for building automated test suites because they allow you to easily capture the code passed to the assertion, along with information on where the assertion was made. While this information can be captured via other methods, using assertions makes it much faster and easier! The callback function should accept three arguments. The first argument will contain the file the assertion failed in. The second argument will contain the line the assertion failed on and the third argument will contain the expression that failed (if any — literal values such as 1 or "two" will not be passed via this argument). Users of PHP 5.4.8 and later may also provide a fourth optional argument, which will contain the description given to assert, if it was set. assert is a language construct in PHP 7, allowing for the definition of expectations: assertions that take effect in development and testing environments, but are optimised away to have zero cost in production. While assert_options can still be used to control behaviour as described above for backward compatibility reasons, PHP 7 only code should use the two new configuration directives to control the behaviour of assert and not call assert_options. Directive Default value Possible values zend.assertions 1 1: generate and execute code (development mode) 0: generate code but jump around it at runtime -1: do not generate code (production mode) assert.exception 0 1: throw when the assertion fails, either by throwing the object provided as the exception or by throwing a new AssertionError object if exception wasn't provided 0: use or generate a Throwable as described above, but only generate a warning based on that object rather than throwing it (compatible with PHP 5 behaviour) &reftitle.parameters; assertion The assertion. In PHP 5, this must be either a string to be evaluated or a bool to be tested. In PHP 7, this may also be any expression that returns a value, which will be executed and the result used to indicate whether the assertion succeeded or failed. Using string as the assertion is DEPRECATED as of PHP 7.2.0 and REMOVED as of PHP 8.0.0. description An optional description that will be included in the failure message if the assertion fails. From PHP 7, if no description is provided, a default description equal to the source code for the invocation of assert is provided. exception In PHP 7, the second parameter can be a Throwable object instead of a descriptive string, in which case this is the object that will be thrown if the assertion fails and the assert.exception configuration directive is enabled. &reftitle.returnvalues; &false; if the assertion is false, &true; otherwise. &reftitle.changelog; &Version; &Description; 8.0.0 assert will no longer evaluate string arguments, instead they will be treated like any other argument. assert($a == $b) should be used instead of assert('$a == $b'). The assert.quiet_eval &php.ini; directive and the ASSERT_QUIET_EVAL constant have also been removed, as they would no longer have any effect. 8.0.0 Declaring a function called assert() inside a namespace is no longer allowed, and issues E_COMPILE_ERROR. 7.3.0 Declaring a function called assert() inside a namespace became deprecated. Such declaration now emits an E_DEPRECATED. 7.2.0 Usage of a string as the assertion became deprecated. It now emits an E_DEPRECATED notice when both assert.active and zend.assertions are set to 1. 7.0.0 assert is now a language construct and not a function. assertion can now be an expression. The second parameter is now interpreted either as an exception (if a Throwable object is given), or as the description supported from PHP 5.4.8 onwards. &reftitle.examples; Assertion Failed: File '$file'
Line '$line'
Code '$code'

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"; } // Set up the callback assert_options(ASSERT_CALLBACK, 'my_assert_handler'); // Make an assertion that should fail assert('mysql_query("")'); ?> ]]> ]]> &example.outputs; ]]> With zend.assertions set to 0, the above example will output: With zend.assertions set to 1 and assert.exception set to 0, the above example will output: With zend.assertions set to 1 and assert.exception set to 1, the above example will output: ]]> With zend.assertions set to 0, the above example will output: With zend.assertions set to 1 and assert.exception set to 0, the above example will output: With zend.assertions set to 1 and assert.exception set to 1, the above example will output: &reftitle.seealso; assert_options