Senior Sofware Developer Assesment Questions & Answers.

Q1. Write a function ReadXml($xmlstr) which accepts an XML string as its only argument. Your function should write the names of the nodes and their values.

Answer

function ReadXml($xmlstr)
{
    static $res = '';
    $xml = new SimpleXMLElement($xmlstr);
    if(count($xml->children()))
    {
        $res .= $xml->getName().PHP_EOL;
        foreach($xml->children() as $child)
        {
            ReadXml($child->asXML());
        }
    }
    else
    {
        $res .= $xml->getName().': '.(string)$xml.PHP_EOL;
    }

    return $res;
}

Q2. Consider a database with one table called user having two fields: 'id' (type: INTEGER, PRIMARY KEY) 'name' (type: VARCHAR(32)) Write a standard SQL query which retrieves the second highest value of 'id' from the 'user' table. The value returned should be represented using the column name 'id'

Answer:

SELECT id FROM user ORDER BY id DESC LIMIT 1,1

Q3. You are given an HTML form, which contains the following entries: … The form has been submitted using the ‘POST’ method. Identify, which of the check-boxes and write (output) their numbers in increasing order. Separate all numbers by spaces (not new lines) and do not use any HTML formatting. For example, if check-boxes 3, 5, and 10 are checked, the only valid output would be: 3 5 10

Answer:

$res = array();
while(list($checkbox,) = each($_POST))
{
    $res[] = intval(substr($checkbox,strpos($checkbox,'_') + 1));
}
sort($res);
echo implode(' ',$res);

Q4. Write a function GetUniqueOnes, which accepts a single argument. The argument is an array of integers, and the function should return the unique integers separated by commas

Answer:

function GetUniqueOnes($arr)
{
    $res = implode(',',array_unique($arr));

    return $res;
}

Q5. Write a function GeneratePassword which accepts two arguments, an integer and a character string consisting of letters (a-z) and digits (0-9).

Answer:

function GeneratePassword ($length,$chars)
{
    $res = '';
    $char_length = strlen($chars);
    for($i = 0; $i < $length; $i++)
    {
        $res .= $chars[rand(0,$char_length)];
    }

    return $res;
}

Q6. Write a function declared as function SplitEmailAddress($address),whose argument will contain string data consisting of a valid e-mail address. This function will take the email address as the argument and return an array with two keys: user for the username part and domain for the domain part of the address. For example, after calling:

$arr = SplitEmailAddress('myuser_1@mailserver.example.com')
$arr['user'] should contain the string myuser_1and
$arr['domain'] should contain the string mailserver.example.com

Answer:

function SplitEmailAddress($address)
{
    list($user, $domain) = explode('@',$address);
    return array('user' => $user, 'domain' => $domain);
}

Q7. Write a function declared as function ReformatPhoneNumber($number), whose argument will contain string data representing some phone number data (entered by the user). A valid phone number may consist of between 7 and 12 digits (0..9). Assume that in between some adjacent digits there may optionally appear either a single space, or a single hyphen (-). Any other phone number should be considered invalid.If the phone number is valid, the return value of your function should contain a string containing between 7 and 12 digits, representing the same phone number after removing all hyphens and spaces. If the phone number is invalid, throw a standard PHP5 Exception initialized with the text ‘Invalid phone number’.The first and the last character of the string should be a number.For example, after calling ReformatPhoneNumber(012-345 69) the return value should be 01234569. Calling the function with any of these values: 012345, -012345 678, 01203- 34566, 123456678875432, 1234×567 should result in an exception.

Answer:

function ReformatPhoneNumber($number)
{
    if (preg_match('/^(\d[ -]?){7,12}$/', $number, $matches))
    {
        return preg_replace('/[ -]/', '', $number);
    }

    throw new Exception('Invalid phone number');
}

Q8. Write a function GetLongestString, whose arguments are character strings. It should return an integer representing the length of the longest string passed as its argument; for example: GetLongestString('a', 'aaa', 'aa') should return 3, GetLongestString('a', 'bcd', 'efgh', 'ij', '') should return 4.

Answer:

function GetLongestString()
{
    $length = 0;
    foreach(func_get_args() as $arg)
    {

        $var = strlen($arg);
        if($var > $length)
        {
            $length = $var;
        }
    }
    return $length;
}

Q9. You are given an array in PHP, which contains positive integers and/or recursively nested arrays of positive integers. It may, for example, be initialized as:$arr = array(array(141,151,161), 2, 3, array(101, 202, array(303,404)));Write a function “function MaxArray($arr)” which returns the maximum value contained in $arr or some array nested within $arr. In the example, the returned value should be 404.

Answer:

function MaxArray($arr)
{
    $GLOBALS['max'] = 0;
    array_walk_recursive($arr,create_function('$item,$key','if($item > $GLOBALS["max"]) $GLOBALS["max"] = $item;'));
    return $GLOBALS['max'];
}

Q10. Write a program that outputs the numbers that are divisible by 8 and are between 200 and 600 (inclusive), separated by commas (without spaces or line breaks).

Answer:

for($i = 200; $i <= 592; $i+=8)
{
    echo $i.',';
}
echo $i;

Q11. OOP Concept

Somebody has defined a class called Product as follows:

class Product 
{ 
    private $name; 
    private $price; 
    
    public function Product($name, $price) 
    {
        $this->name = $name;
        $price = $this->price;
    } 

    protected function setName($name) 
    { 
        
        return $this->name = ($name == $this->name); 
    } 

    protected function setPrice($price) 
    { 
        
        return $price = $this->price = $price; 
    } 

    final public function ShowNameAndPrice () 
    {
        echo "This product is called {$this->name} and costs {$this->price} USD.";
    }
} 

Your task is to write a class called FixedProduct which extends the class Product in such a way that e.g. writing:

$prod = new FixedProduct ("a book", "19.99");
$prod->ShowNameAndPrice();

will display the text: This product is called a book and costs 19.99 USD. Remember you only need to write the class.

Answer:

class FixedProduct extends Product {
    
    public function FixedProduct($name, $price)
    {
        $price = $this->setPrice($price);
        parent::__construct($name, $price);
    }
} `

General error: 2014 Cannot execute queries while other unbuffered queries are active.  Consider using PDOStatement::fetchAll().  Alternatively, if your code is only ever going to run against mysql, you may enable query buffering by setting the PDO::MYSQL_ATTR_USE_BUFFERED_QUERY attribute.