Ok, I’ll bite in response to this “Where did all the PHP programmers go?” blog post:
What I cannot understand is why people with more than one Bachelor Degree in Computer Science recommend using bubble sort.
Sounds wrong but harmless, as you don’t write a sort implementation from scratch in PHP. You write the comparators used for the sort order, but the actual sort implementation is provided for you by language. I presume it uses qsort internally, but don’t know for sure. I have a degree in CS, and I can scarcely even recall the bubble sort algorithm (or even most of the sort algorithms for that matter), for the simple reason that it doesn’t matter in the real world (in 99% of cases) for web developers using scripting languages. That may sound (gasp) shocking, but it’s true - PHP is not a performance-orientated language, and it’s a fairly high-level language with a decent library of native functions, so you don’t generally write sort algorithms (rather you use the library ones that are provided for you, unless you have an overwhelmingly good reason not to).
The question you need to ask is: are you running a Computer Science class on sorting algorithms, or are you looking for people who know PHP and can get your thing built?
“What is the difference between the stack (also known as FILO) and the queue (also known as pipe, also known as FIFO)?”
Maybe rephrase the question to “you want to store multiple bits of information in a data structure or an array or a collection of some sort. How would you add data to the beginning of that data structure, and how would you remove data from the end?”
I.e. focus less on the Computer Science theory, and more on the application of it.
“Using PHP programming language, create a list to store information about people. For each person you’ll need to store name, age, and gender. Populate the list with three sample records. Then, print out an alphabetically sorted list of names of all males in that list. Bonus points for not using the database.”
Here’s a trivial implementation just using arrays, I don’t claim it’s remotely pretty or elegant, and I wrote just to see what’s involved in the above task:
<?php
error_reporting( E_STRICT | E_ALL );
function sort_by_name( $a, $b ) {
if( $a['name'] === $b['name'] ) return 0;
return $a['name'] > $b['name'];
}
function printMales( $array ) {
foreach( $array as $person ) {
if( $person['gender'] != 'male') continue;
print "Name: " . $person['name'] . "\n";
}
}
$people = array( array( 'name' => 'Bob' , 'age' => 36, 'gender' => 'male' ),
array( 'name' => 'Alice' , 'age' => 23, 'gender' => 'female' ),
array( 'name' => 'Doug' , 'age' => 63, 'gender' => 'male' ),
);
print "Before:\n";
print_r( $people );
usort( $people, 'sort_by_name' );
print "After:\n";
print_r( $people );
print "\n";
printMales( $people );
?>
But you know what? I had to look up the PHP manual for usort because I couldn’t recall off the top of my head whether it was “u_sort” or “usort”, and I couldn’t recall the parameters and their order. Also I had 3 trivial syntax errors that I fixed in 15 seconds. Now, I really hope for this pen-and-paper test that you are giving people access to the PHP manual, or if you are not that you are being very tolerant of minor syntactical errors or people who can’t recall whether the function name has an underscore, or who can’t recall the exact order of the parameters, and so forth. Because the question is: Is this a test of whether someone has memorized the entire PHP manual, or is this a test of whether people who can do what you want? Because when they are working, then you will give them access to the PHP manual - right?! If you want to distress people in the interview, then sure, treat it as a rote memory test of the PHP manual and Computer Science theory, and make it awkward if they get anything wrong - but if you’ve want to solve the problem of finding people then there has to be some leeway for recollection of technical trivia that you can find through Google in a few seconds.
Look, I’ve been in a similar situation of looking for PHP people to hire (the candidates were from China in this case), and the approach we used was to give them a test beforehand that they could do (in 24 hours of their own time), and then if they looked okay then they could get called in for an interview. This allowed culling people who were very bad, or who gave code that didn’t run - as there really is very little excuse for code that’s invalid or that doesn’t work if you’ve got 24 hours and access to the internet and your own computer. Most of the people weren’t great, some were very bad, and some were okay. If it helps, that PHP test is here, and it’s only intended to be a very simple test.
