Good PHP code should be structured; good PHP code should be standardized; good PHP code should be adaptive; good PHP code should be safe...
I will definitely ask this when I am an interviewer at SitePoint The question is: What do you think are the advantages and disadvantages of PHP code? Because this question can give me a general idea of what type of programmer the candidate is, rather than simply testing his mastery of PHP functions (Zend’s PHP certification is good at this, and Yahoo’s PHP programmer interview questions are also such).
Importantly, this question lets me know if the candidate has experienced taking over a piece of messy code from a lazy programmer to reuse, or helping other members of the team with this type of thing.
Admittedly, I don't have a satisfactory answer to this question myself, but I know the answers I want to hear:
Good PHP code should be structured. Large sections of code should be divided into functions or methods, while small sections of code that are not eye-catching should be commented so that their purpose will be clear later. And the front-end code such as HTML, CSS, Javascript, etc. should be separated from the program as much as possible. PHP's object-oriented programming features can help programmers organize their code in an orderly manner.
Good PHP code should be standardized. Whether it's setting naming rules for variable and function names, standardizing reusable processes such as database operations and error handling, or as simple as specifying how code should be indented, these standardizations can make the code more readable. Readability is greatly improved.
Good PHP code should be adaptive. PHP has many features such as magic quotes and short tags. Turning these features on and off will affect the running of the program. Therefore, a good programmer should add appropriate statements to his code so that the program can adjust according to the environment.
Good PHP code should be safe. Although PHP is an efficient and flexible language with no fixed framework, it leaves security issues to programmers. A deep understanding of potential security vulnerabilities, such as cross-site scripting (XSS), cross-site request forgery (CSRF), code injection vulnerabilities, character encoding loop vulnerabilities, etc., is crucial for today's professional programmers.
When a candidate answers these questions, I know clearly whether I should hire him or her. Of course, sometimes programmers can't articulate the problem well, and we ask them to do some PHP testing. Many of the questions in the test may seem very simple on the surface, but they also give candidates a chance to express themselves, because if you look carefully, you can spot the problems.
The following small piece of "poor" PHP code is a simplified test question. This question is like asking: How should you optimize this code?
<?
echo("<p>Search results for query: " .
$_GET['query'] . ".</p>");
?>
The main problem with this code is that it displays the data submitted by the user directly on the web page, thus creating an XSS vulnerability. There are actually many ways to fill this hole. So, what code do we want?
<?
echo("<p>Search results for query: " .
htmlspecialchars($_GET['query']) . ".</p>");
?>
This is the minimum requirement. The XSS vulnerability was filled with the htmlspecialchars function, thus blocking illegal characters.
<?php
if (isset($_GET['query']))
{
echo '<p>Search results for query: ',
htmlspecialchars($_GET['query'], ENT_QUOTES), '.</p>';
}
?>
People who can write such code should be the ones I want to hire.
<? was replaced by <?php, which is more consistent with XML specifications.
Before outputting the value of $_GET['query'], first determine whether it is empty.
The extra parentheses in the echo command have been removed.
Strings are qualified with single quotes, which saves PHP time searching for replaceable variables in the string.
Use commas instead of periods to save echo time.
Pass the ENT_QUOTES flag to the htmlspecialchars function to ensure that single quotes are also escaped. Although this is not the most important thing, it is also a good habit.
Unfortunately, there are very few programmers who can give such a satisfactory answer. It took us 3 months to recruit programmers that we were satisfied with.
So, how would you answer the question posed at the beginning of this article? What do you think are the advantages and disadvantages of PHP code? What other qualities do you think a PHP programmer should have?
This article comes from: http://www.yeeyan.com/articles/view/38585/18736
Original link: http://www.sitepoint.com/blogs/2007/05/25/good-and-bad-php-code/