<p>1. Which of the following will not add john to the users array?<br />
1. $users[] = ‘john’;<br />
2. array_add($users,’john’);<br />
3. array_push($users,’john’);<br />
4. $users ||= ‘john’;<br />
Answer: 2,4<br />
2. What’s the difference between sort(), asort() and ksort(),rsort()? Under what circumstances would you use each of these?<br />
sort(): 本函数对数组的值进行排序。当本函数结束时数组单元将被从最低到最高重新安排,array 中的单元赋予新的键名。这将删除原有的键名而不仅是重新排序。<br />
asort(): 这个函数将数组的值重新排序，由小至大排列。数组的索引亦跟着值的 顺序而变动。当您在程序中需要重新整理数组值的 顺序时，就可以使用这个函数。<br />
ksort(): 对数组按照键名排序，保留键名到数据的关联。本函数主要用于关联数组。<br />
rsort(): 本函数对数组进行逆向排序（最高到最低）。与sort()执行相反的操作。<br />
3. What would the following code print to the browser? Why?<br />
$num = 10;<br />
function multiply(){<br />
$num = $num * 10;<br />
}<br />
multiply();<br />
echo $num;<br />
10<br />
4. What is the difference between a reference and a regular variable? How do you pass by reference & why would you want to?<br />
pass by reference like this functions(&$vars);<br />
it likes more fast;<br />
5. What functions can you use to add library code to the currently running script?<br />
inlcude() or require();<br />
6. What is the difference between foo() & @foo()?<br />
if foo() throw a error, will be alert, but @foo() no;<br />
7. How do you debug a PHP application?<br />
xdebug or use die() do it;<br />
8. What does === do? What’s an example of something that will give true for ‘==’, but not ‘===’?<br />
=== 用于精确比较 ex: (” == null) => true but ( ”===null) =>false;<br />
9. How would you declare a class named “myclass” with no methods or properties?<br />
class myclass{<br />
}<br />
10. How would you create an object, which is an instance of “myclass”?<br />
$myoject = new myclass();<br />
11. How do you access and set properties of a class from within the class?<br />
getVar() or setVar() ;<br />
12. What is the difference between include & include_once? include & require?<br />
require:PHP 程式在执行前，就会先读入 require 所指定引入的档案，使它变成 PHP 程式网页的一部份。常用的函式，亦可以这个方法将它引入网页中。错误产生致命错误。<br />
include:这个函式一般是放在流程控制的处理区段中。PHP 程式网页在读到 include 的档案时，才将它读进来。这种方式，可以把程式执行时的流程简单化。错误产生警报。<br />
include_once:此行为和include()语句类似，唯一区别是如果该文件中的代码已经被包含了，则不会再次包含。如同此语句名字暗示的那样，只会包含一次。<br />
13. What function would you use to redirect the browser to a new page?<br />
1. redir()<br />
2. header()<br />
3. location()<br />
4. redirect()<br />
2<br />
14. What function can you use to open a file for reading and writing?<br />
1. fget();<br />
2. file_open();<br />
3. fopen();<br />
4. open_file();<br />
3<br />
15. What’s the difference between mysql_fetch_row() and mysql_fetch_array()?<br />
mysql_fetch_row():返回根据所取得的行生成的数组，如果没有更多行则返回 FALSE。<br />
mysql_fetch_array(): 是mysq_fetch_row()的扩展版本。除了将数据以数字索引方式储存在数组中之外，还可以将数据作为关联索引储存，用字段名作为键名。<br />
16. What does the following code do? Explain what’s going on there.<br />
$date=’08/26/2003′;<br />
print ereg_replace(’([0-9]+)/([0-9]+)/([0-9]+)’,'2/1/3′,$date);<br />
本函数以 正则 的规则来解析比对字符串 ，欲取而代之的字符串为’2/1/3′。<br />
返回值为字符串类型，为取代后的字符串结果。<br />
17. Given a line of text $string, how would you write a regular expression to strip all the HTML tags from it?<br />
strip_tags<br />
18. What’s the difference between the way PHP and Perl distinguish between arrays and hashes?<br />
19. How can you get round the stateless nature of HTTP using PHP?<br />
20. What does the GD library do?<br />
21. Name a few ways to output (print) a block of HTML code in PHP?<br />
22. Is PHP better than Perl? ? Discuss.<br />
如果成功则返回 TRUE，失败则返回 FALSE。</p>