PHP Level 1

1. Which of the following is an example of the use of an arithmetic operator?

While (true) { echo "x"; }

F(10)

$a + $b

$n = array( 1, 3, 9, 27 );

Print "10 - 5 = 5";

In C, the "+" is an arithmetic operator. The other operator, in D, is =, which is an assignment operator.

Explanation

In C, the "+" is an arithmetic operator. The other operator, in D, is =, which is an assignment operator.

2. Which of the following is a function call.

Fib(5)

( $i > LAST_ITEM )

$n = 100;

5 + 10

Function total( $x, $y, $z ) { return $x + $y + $z; }

The function is fib(). Choice E is incorrect, because it's a function definition. A "call" is when you use a function.

Explanation

The function is fib(). Choice E is incorrect, because it's a function definition. A "call" is when you use a function.

3. Which of the following doesn't look like PHP code?

$a = 10;

If ($this->isComplete()) echo "finished";

Printf('%d',10);

Document.writeln(requestObject.parameter("id"))

Echo $switch ? $switch : '';

D is a mishmash of Javascript and VBScript, and uses the dot notation for objects. PHP uses the arrow notation.

Explanation

D is a mishmash of Javascript and VBScript, and uses the dot notation for objects. PHP uses the arrow notation.

4. Which of the following is not a supported syntax to call a method on an object or a class?

MyClass::myMethod($x);

$obj->myMethod($x);

$obj.myMethod($x);

$n = new MyClass(10)->myMethod($x);

$obj->$funcName($parameter);

C - the dot notation is not supported. Choice E is legitimate.

Explanation

C - the dot notation is not supported. Choice E is legitimate.

5. You have a large array of names, sorted randomly, and you need to extract all the names that start with the letter "M". What kind of magical PHP incantations will appear in your code?

For(....), if (....) { $a[] = ... }

Foreach(....) preg_match

Map( function () = '....' ); substr(); array_push();

Grep(); keys(); unshift()

Array(... select from( where(...) );

C will produce the shortest code. It's esoteric, but easy to understand once you understand it. D and E were red herrings.

Explanation

C will produce the shortest code. It's esoteric, but easy to understand once you understand it. D and E were red herrings.

6. Computer scientists like recursion. In the real world, especially on multi-user situations like PHP faces, recursion isn't so popular. There are many reasons why people forego recursion. Which of the following is usually not a reason.

Function calls are expensive.

Function call stack can run out of space.

Consumes lots of memory.

Difficult to understand.

It's easier to use arrays and indices.

If it's easily solved by recursion, it's rarely every easier to solve it with arrays.

Explanation

If it's easily solved by recursion, it's rarely every easier to solve it with arrays.

7. PHP runs on many platforms, mainly Unixes. When you run code developed on a Snix machine and move it over to a Windows server, which issue below is not likely to be a problem.

Case folding causes similarly named files to overwrite another.

Calling mail() fails.

Executing code that calls OLE fails.

File paths stop working.

Missing or not-ported extensions.

C is a red herring. OLE is a Windows technology.

Explanation

C is a red herring. OLE is a Windows technology.

8. You whipped up a little MySQL database backed website, and now the traffic has exploded. The server is slowing down. Listed are some ways you can reduce the load. Which will give you the least gain?

Analyze your queries, and add indexes to tables to speed them up.

Add an object cache like APC or Zend.

Generate a static home page, and for some internal pages.

Move the database to it's own machine and connect to it via TCP/IP

Use memcached to store serialized query results, and use it as a result cache.

B - the bottleneck is the database and the fact it goes to disk to get results. An object cache only helps avoid compilation, but doesn't address the DB speed issue. Separating the database to its own machine is also not likely to help much normally, but, simply doubling the number of CPUs will definitely gain performance on heavily loaded servers.

Explanation

B - the bottleneck is the database and the fact it goes to disk to get results. An object cache only helps avoid compilation, but doesn't address the DB speed issue. Separating the database to its own machine is also not likely to help much normally, but, simply doubling the number of CPUs will definitely gain performance on heavily loaded servers.

9. Here is a dense, faulty bit of PHP code that just won't work. You know, the kind your coworker wrote (lulz). All of the following reasons, except one, are reasons why the code isn't working.
$a = $POST['name'];
print 'Hello $a ';
include('db_layer.inc.php'); // connects to db
$db = new db();
$db->insert("insert into foobar (name) $a");
?>

The POST variable name is wrong.

The input is not escaped and quoted before being inserted into the query.

The "Hello" message was quoted incorrectly, and won't display the arugment.

The input is not sanitized before printing to the browser.

An HTML tag is not closed.

D - while not sanitizing input is punishable by humiliation, it won't prevent the code from running.

Explanation

D - while not sanitizing input is punishable by humiliation, it won't prevent the code from running.

10. Your client says they want to build a clone of Craigslist or Kijiji. You think they're nuts, but they convince you they can do it. Around how many data tables do you think it will take?

5

10

50

300

2000

It's a pretty small application, despite it's popularity. C or D could be correct answers.

Explanation

It's a pretty small application, despite it's popularity. C or D could be correct answers.

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