YAHOO PHP面试题

知道差距了，努力吧！
1. Which of the following will not add john to the users array?
1. $users[] = 'john';
2. array_add($users,'john');
3. array_push($users,'john');
4. $users ||= 'john';
2. What's the difference between sort(), asort() and ksort? Under what circumstances would you use each of these?
3. What would the following code print to the browser? Why?
$num = 10;
function multiply(){
$num = $num * 10;
}
multiply();
echo $num;
4. What is the difference between a reference and a regular variable? How do you pass by reference & why would you want to?
5. What functions can you use to add library code to the currently running script?
6. What is the difference between foo() & @foo()?
7. How do you debug a PHP application?
8. What does === do? What's an example of something that will give true for '==', but not '==='?
9. How would you declare a class named “myclass” with no methods or properties?
10. How would you create an object, which is an instance of “myclass”?
11. How do you access and set properties of a class from within the class?
12. What is the difference between include & include_once? include & require?
13. What function would you use to redirect the browser to a new page?
1. redir()
2. header()
3. location()
4. redirect()
14. What function can you use to open a file for reading and writing?
1. fget();
2. file_open();
3. fopen();
4. open_file();
15. What's the difference between mysql_fetch_row() and mysql_fetch_array()?
16. What does the following code do? Explain what's going on there.
$date='08/26/2003';
print ereg_replace(“([0-9]+)/([0-9]+)/([0-9]+)”,2/1/3,$date);
17. Given a line of text $string, how would you write a regular expression to strip all the HTML tags from it?
18. What's the difference between the way PHP and Perl distinguish between arrays and hashes?
19.