Technology MCQ and Descriptive Questions & Answers

I have been getting errors while using the mysql and mysqli .  

<?php
$con=mysql_connect("localhost", "root" ,"" ,"mysql");
if( mysqli_connect_errno( $con ) ) {
    echo "failed to connect";
}else{
    echo "connected";
}
mysqli_close($con);
echo "Done";
?>

error: 

Connected
Warning: mysql_close() expects parameter 1 to be resource, object given in D:\************.php on line 9
Done

When using mysql_real_escape_string() function, Is there an SQL injection possibility even ?  

If I look at the following PHP code : 

$Id= mysql_real_escape_string($_GET('login'));
$password = mysql_real_escape_string($_GET('password'));

$sql = "SELECT * FROM table WHERE login='$id' AND password='$password'";

Is there any possible injection that would get through the PHP code above?

An Application when ask the user to input  and submit the information, It is inserted without modification into an SQL query, then the application becomes vulnerable to SQL injection -

$variable = $_POST['user_input']; 
mysql_query("INSERT INTO `table` (`column`) VALUES ('$variable ')");

What if user input something like DML statement such as:

INSERT INTO `table` (`column`) VALUES('value'); DROP TABLE table;--')

Could you suggest the ways to decode the JSON from the following code  - How to extract data from JSON with PHP?.

{
    "type": "coffee",
    "name": "brew",
    "toppings": [
        { "id": "500", "type": "Creme" },
        { "id": "501", "type": "Chocolate with Sprinkles" },
        { "id": "502", "type": "Ice Creme" }
    ]
}

The mysql database date format is in YYYY-MM-DD format. How to change it to MM-DD-YYYY or for example DD-MON-YYYY ?

There are common questions on PHP Arrays..

How do I sort a complex array in PHP?

How do I sort an array of objects in PHP?

How can I sort the following array by the value of the "order" key? The values are currently sequential, they will not always be.

Array
(
    [0] => Array
        (
            [hashtag] => a7e87329b5eab8578f4f1098a152d6f4
            [title] => Flower
            [order] => 3
        )

    [1] => Array
        (
            [hashtag] => b24ce0cd392a5b0b8dedc66c25213594
            [title] => Free
            [order] => 2
        )

    [2] => Array
        (
            [hashtag] => e7d31fc0602fb2ede144d18cdffd816b
            [title] => Ready
            [order] => 1
        )
)

Each website is required to have sitemap and needs to be submitted regularly to google.com or bing /other search engines webmasters. I am trying to create customized XML sitemap for my website using PHP.. here is my code below

<?php echo'<?xml version="1.0" encoding="UTF-8"?>' ?>
<urlset xmlns="http://www.sitemaps.org/schemas/sitemap/0.9">
    <url>
    <loc><?php echo 'https://websitename.com';?></loc>
    <lastmod><?php echo $lastmod; ?></lastmod>
    <priority>1.0</priority>
</url>
<?php foreach($items as $item) { ?>
<url>
    <loc><?php echo "https://websitename.com/".$item->url_seg ?></loc>
    <lastmod><?php echo $lastmod; ?></lastmod>
    <priority>0.80</priority>
</url>
<?php } ?>
</urlset>

Still the the code is not showing the XML format file..

The array_merge() is a builtin function in PHP and is used to merge two or more arrays into a single array. This function is used to merge the elements or values of two or more arrays together into a single array.  i.e.

Syntax:

array array_merge($array1, $array2, ......, $arrayn)

How to merge two arrays?

I want to go to next employee id only after doing successful action on each emp_id

$draft_query = $this->db->get_where('employee');
  if ( $draft_query->num_rows() > 0 )
   {
          foreach ($draft_query->result() as $row)
             {  
                $emp_id   = $row->emp_id;

             }
     }

What does PHP stand for ?

(i) Personal Home Page

(ii) Hypertext Preprocessor

(iii) Pretext Hypertext Processor

(iv) Preprocessor Home Page

Which of the following is/are a PHP code editor ?

(i) Sublime text

(ii) Notepad++

(iii) Adobe Dreamweaver

(iv) PDT

Which of the following must be installed on your computer so as to run PHP script?

(i) Adobe Dreamweaver

(ii) WAMP

(iii) Apache and PHP

(iv) IIS

How should we add a single line comment in our PHP code ?

(i) /?

(ii) //

(iii) #

(iv) /* */

Which of the following PHP statement/statements will store 111 in variable num ?

    i) int $num = 111;
    ii) int mum = 111;
    iii) $num = 111;
    iv) 111 = $num;

What will be the output of the following PHP code?

    <?php
    $num  = 1;
    $num1 = 2;
    print $num . "+". $num1;
    ?>

What will be the output of the following PHP code ?

    <?php
    $num  = "1";
    $num1 = "2";
    print $num+$num1;
    ?>

Which is the right way of declaring a variable in PHP?

(i) $3hello

(ii) $_hello
(iii) $this
(iv) $This

What will be the output of the following PHP code?

    <?php 
    $foo = 'Bob';              
    $bar = &$foo;              
    $bar = "My name is $bar";  
    echo $bar;
    echo $foo;
    ?>

Which of the following PHP statements will output Hello World on the screen?

(i) echo ("Hello World");
(ii) print ("Hello World");
(iii) printf ("Hello World");
(iv) sprintf ("Hello World");

What will be the output of the following PHP code?

    <?php
    $color = "maroon";
    $var = $color[2];
    echo "$var";
    ?>

What will be the output of the following PHP code?

    <?php
    $score = 1235;
    $scoreboard = (array) $score;
    echo $scoreboard[0];
    ?>

Which of the below statements is equivalent to $add += $add?

Which statement will output $x on the screen?

What will be the output of the following PHP code?

<?php
    $a = "clue";
    $a .= "get";
    echo "$a";
    ?>

What will be the output of the following PHP code?

    <?php
    function track() {
    static $count = 0;
    $count++;
    echo $count;
    }
    track();
    track();
    track();
    ?>

What will be the output of the following PHP code?

    <?php
    $total = "25 students";
    $more = 10;
    $total = $total + $more;
    echo "$total";
    ?>