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

What is the difference between print() and echo()?

There are three different kind of arrays:

What functions count elements in an array?

What array will you get if you convert an object to an array?

Assume you would like to sort an array in ascending order by value while preserving key associations. Which of the following PHP sorting functions would you use?

What is the difference between stat() and fstat()?

The ........... function is used to read a single character from a file.

Which of the following functions do not return a timestamp? 

The ......... function parses an English textual date or time into a Unix timestamp