How to properly use PHP7 expectations

php7Expect backward-compatible enhancements to the old assert() function. Expectations allow zero-cost assertions in production code and provide the ability to throw custom exceptions when assertions fail. assert() is not a language construct where the first argument is a comparison of an expression string or boolean for testing.

Configuration directive assert()

##InstructionsDefault valuePossible valueszend.assertions1assert.exception0

		1 \- Generate and execute code (development mode ) 0 \- Generate code, but skip it at runtime -1 \- Do not generate code (production mode)
		1 \- Throws the exception object provided when the assertion fails, or throws a new AssertionError object if no exception is provided. . 0 \- Use or generate a Throwable as above, but only generate a warning based on that object instead of throwing it (compatible with PHP 5 behavior)

Parameters:

• Assertion - Assertion. In

  PHP 5, it must be a string to be evaluated or a boolean value to be tested. In PHP 7, this can also be any expression that returns a value that will be executed and the result used to indicate whether the assertion succeeded or failed.

• Description - An optional description that will be included in the failure message if the assertion fails.

• 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.

Return value

If the assertion is false, it returns

FALSE, otherwise it returns TRUE .

Example:

<?php
   ini_set(&#39;assert.exception&#39;, 1);

   class CustomError extends AssertionError {}

   assert(false, new CustomError(&#39;Custom Error Message!&#39;));
?>

It produces the following browser output:

Fatal error: Uncaught CustomError: Custom Error Message! in...

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