Interview Questions for PHP - 4 - Answers

Back - Interview Questions for PHP - 4

Q1. Ans - The output is displayed directly to the browser.

Q2. Ans - If you want to create a table, you can run the CREATE TABLE statement as shown in the following sample script:

<?php

include "mysql_connection.php";

$sql = "CREATE TABLE astore ("

. " id INTEGER NOT NULL"

. ", url VARCHAR(80) NOT NULL"

. ", notes VARCHAR(1024)"

. ", counts INTEGER"

. ", time TIMESTAMP DEFAULT sysdate()"

. ")";

if (mysql_query($sql, $con)) {

print("Table Astore created.\n");

} else {

print("Table creation failed.\n");

}

mysql_close($con);

?>

Remember that mysql_query() returns TRUE/FALSE on CREATE statements. If you run this script, you will get something like this:

Table Astore created.

Q3. Ans - The include_once() statement includes and evaluates the specified file during the execution of the script. This is a behavior similar to the include() statement, with the only difference being that if the code from a file has already been included, it will not be included again. The major difference between include() and require() is that in failure include() produces a warning message whereas require() produces a fatal errors.

Q4. Ans - string urlencode(str) - Returns the URL encoded version of the input string. String values to be used in URL query string need to be URL encoded. In the URL encoded version:

Alphanumeric characters are maintained as is.

Space characters are converted to "+" characters.

Other non-alphanumeric characters are converted "%" followed by two hex digits representing the converted character.

string urldecode(str) - Returns the original string of the input URL encoded string.

For example:

$discount ="10.00%";

$url = "http://domain.com/submit.php?disc=".urlencode($discount);

echo $url;

You will get "http://domain.com/submit.php?disc=10%2E00%25".

Q5. Ans - Once the Web server received the uploaded file, it will call the PHP script specified in the form action attribute to process them. This receiving PHP script can get the uploaded file information through the predefined array called $_FILES. Uploaded file information is organized in $_FILES as a two-dimensional array as:

$_FILES[$fieldName]['name'] - The Original file name on the browser system.

$_FILES[$fieldName]['type'] - The file type determined by the browser.

$_FILES[$fieldName]['size'] - The Number of bytes of the file content.

$_FILES[$fieldName]['tmp_name'] - The temporary filename of the file in which the uploaded file was stored on the server.

$_FILES[$fieldName]['error'] - The error code associated with this file upload.

The $fieldName is the name used in the <INPUT TYPE=FILE, NAME=fieldName>.

Q6. Ans - MySQL fetch object will collect first single matching record where mysql_fetch_array will collect all matching records from the table in an array.

Q7. Ans - Just run the PHP CLI (Command Line Interface) program and provide the PHP script file name as the command line argument. For example, "php myScript.php", assuming "php" is the command to invoke the CLI program.

Be aware that if your PHP script was written for the Web CGI interface, it may not execute properly in command line environment.

Q8. Ans - PHP Interpreter treats numbers beginning with 0 as octal.

Q9. Ans - Total 5 types of tables we can create

1. MyISAM

2. Heap

3. Merge

4. INNO DB

5. ISAM

MyISAM is the default storage engine as of MySQL 3.23. When you fire the above create query MySQL will create a MyISAM table.

Q10. Ans - define() directive, like define ("MYCONSTANT", 100).