每日一题（9）

15. Run-time inclusion of a PHP scrīpt is performed using the ________ construct, while compile-time inclusion of PHP scrīpts is performed using the _______ construct.

A. include_once, include

B. require, include

C. require_once, include

D. include, require

E.All of the above are correct

Answer:

In recent versions of PHP, the only difference between require() (or require_once()) and include() (or include_once()) is in the fact that, while the former will only throw a warning and allow the scrīpt to continue its execution if the include file is not found, the latter will throw an error and halt the scrīpt. Therefore, Answer E is correct.

16. Under what circumstance is it impossible to assign a default value to a parameter while declaring a function?

A. When the parameter is Boolean

B. When the function is being declared as a member of a class

C. When the parameter is being declared as passed by reference

D. When the function contains only one parameter

E. Never

Answer:

When a parameter is declared as being passed by reference you cannot specify a default value for it, since the interpreter will expect a variable that can be modified from within the function itself. Therefore, Answer C is correct.