Engineering Notes

Thursday, 17 April 2025

JSP ELEMENTS

• Declarations

• Scriptlets

• Expressions

• Comments

• Directives

JSP Declaration

• A declaration tag is a piece of Java code for declaring variables, methods and classes. If we declare a variable or method inside declaration tag it means that the declaration is made inside the servlet class but outside the service method.

• We can declare a static member, an instance variable (can declare a number or string) and methods inside the declaration tag.

Syntax of declaration tag:

<%! Dec var %>

Example

<%! int count =10; %>

<% out.println("The Number is " +count); %>

JSP Scriptlet

• Scriptlet tag allows to write Java code into JSP file.

• JSP container moves statements in _jspservice() method while generating servlet from jsp.

• For each request of the client, service method of the JSP gets invoked hence the code inside the Scriptlet executes for every request.

• A Scriptlet contains java code that is executed every time JSP is invoked.

Syntax of Scriptlet tag:

<% java code %>

Example

<body>

int num1=10;

int num2=40;

int num3 = num1+num2;

out.println("Scriplet Number is " +num3);

</body>

JSP Expression

• Expression tag evaluates the expression placed in it.

• It accesses the data stored in stored application.

• It allows create expressions like arithmetic and logical.

• It produces scriptless JSP page.

Syntax:

<%= expression %>

Example

<% out.println("The expression number is "); %>

<% int num1=10; int num2=10; int num3 = 20; %>

<%= num1*num2+num3 %>

JSP Comments

• Comments are the one when JSP container wants to ignore certain texts and statements.

• When we want to hide certain content, then we can add that to the comments section.

Syntax:

<% -- JSP Comments %>

Example

<%-- Comments section --%>

<% out.println("This is comments example"); %>

JSP directives

JSP directives are the messages to JSP container. They provide global information about an entire JSP page.

• JSP directives are used to give special instruction to a container for translation of JSP to servlet code. • Directives can have many attributes by comma separated as key-value pairs.

• In JSP, directive is described in <%@ %> tags.

There are three types of directives:

1.Page directive

Defines page-dependent attributes, such as scripting language, error page, and buffering requirements. <%@ page attribute = "value" %>

2. Include directive

Includes a file during the translation phase. <%@ include file = "relative url" >

3. Taglib directive

Declares a tag library, containing custom actions, used in the page

<%@ taglib uri="uri" prefix = "prefixOfTag" >

It provides attributes that get applied to entire JSP page.

• It defines page dependent attributes, such as scripting language, error page, and buffering requirements.

• It is used to provide instructions to a container that pertains to current JSP page.

Following are its list of attributes associated with page directive:

Language

Extends

Import

contentType

info

session

isThreadSafe

autoflush

buffer

IsErrorPage

pageEncoding

errorPage

isELIgonored

Wednesday, 5 March 2025

ZOHO On Campus 2024 Codings Programs

Saturday, 6 April 2024

The anatomy of a PHP Page(or) Embedding PHP Code in Your Web Pages

A PHP script is a file (ending with a .php extension) consisting of text, HTML, and PHP instructions interspersed throughout the file.

The PHP instructions are contained within two HTML style tags; is the closing tag. Everything between these two tags is interpreted by the PHP module (also called interpreter) and converted to regular text and HTML before being sent back to the requesting browser.

There are four delimitation variants:

Default Syntax
Short-Tags
Script
ASP Style
Short-circuit syntax

Embedding Multiple Code Blocks :

Commenting Your Code:

Single-Line C++ Syntax
Shell Syntax
Multiple-Line C Syntax (/*………*/)

Default Syntax

The default delimiter syntax opens with

<?php

echo “ First PHP program”;

Output: First PHP program

Short-Tags:

print "This is another PHP example.";

Output: This is another PHP example.

Script

print "This is another PHP example.";

</script>

ASP Style

print "This is another PHP example.";

Short-circuit syntax:

<?=

"This is another PHP example.";

This is functionally equivalent to both of the following variations:

echo "This is another PHP example.";

<?php

echo "This is another PHP example.";

Embedding Multiple Code Blocks:

<html>

<head>

</head>

<body>

<?php

$date = " April 06, 2024";

<p>Today's date is <?=$date;?></p>

</body>

</html>

Commenting Your Code

1. Single-Line C++ Syntax

PHP supports C++

single-line comment syntax, which is prefaced with a double slash (//), like this:

<?php

// Title: My first PHP script

// Author: Narendra

echo "This is a PHP program.";

2.Shell Syntax

PHP also supports an alternative to the C++ style single-line syntax, known as shell syntax, which is prefaced with a hash mark (#).

<?php

# Title: My first PHP script

# Author: Narendra

echo "This is a PHP program.";

3. Multiple-Line C Syntax

PHP also offers a multiple-line variant that can open and close the comment on different lines.

Here’s an example:

<?php

Title: My first PHP script

Author: Narendra

echo "This is a PHP program.";

Outputting Data to the Browser

The simplest of dynamic web sites will output data to the browser, and PHP offers several methods for doing so.

1. print() Statement

2. echo() Statement

3. printf() Statement

4. sprintf() Statement

print() Statement

The print() statement outputs data passed to it . Its prototype looks like this: int print(argument)

Example

<?php

print("<b>welcome to PHP</b>");

echo() Statement

<?php

echo " welcome to PHP ";

printf() Statement

The printf() statement is ideal when you want to output a blend of static text and dynamic information stored within one or several variables.

Example

<?php

printf("Bar inventory: %d bottles of tonic water.", 100); ?>

Output:

Bar inventory: 100 bottles of tonic water.

sprintf() Statement

The sprintf() statement is functionally identical to printf() except that the output is assigned to a string rather than rendered to the browser.

Example

<?php

$cost = sprintf("$%.2f", 43.2);

echo $cost;

Output

$43.20

HTML5 Input Types

HTML5 added several new input types:

New Tags in HTML5

<audio>

<bdi> Bi-Directional Isolation

<embed>

<figcaption> tag defines a caption for a <figure> element

<mark>

<meter>

<nav> tag defines a set of navigation links

<video>

<wbr> (Word Break Opportunity)

<aside>

<main>

<ruby> tag specifies a ruby annotation.

<rp>

<rt>

<time>

<track> tag specifies text tracks for media elements <audio> and <video>

Multi page form in PHP with Example

A multi page form in PHP are used to retain values of a form and can transfer them from one page to another .

multipage.php

<html>

<body>

<p>Page 1 Data Collection:</p>

Your Name: <input type="text" name="yourname" maxlength="150" />

</form>

</div>

</body>

</html>

OUTPUT

multipage2.php

<p>Page 2 Data Collection:</p>

Selection:

<option value="nogo">make a selection...</option>

<option value="Choice1">Choice1</option>

<option value="Choice2">Choice2</option>

<option value="Choice3">Choice3</option>

</select><br /><br />

</form>

</div>

</body></html>

OUTPUT

multipage3.php

<html>

<body>

<p>Page 3 Data Collection:</p>

Your Email: <input type="text" name="youremail" maxlength="150" /><br />

</form>

</div>

</body>

</html>

OUTPUT

multipage4.php

<html>

<?php

//Display the results.

echo "Your Name: " . $_POST['yourname'] . "<br />";

echo "Your Selection: " . $_POST['yourselection'] . "<br />";

echo "Your Email: " . $_POST['youremail'] . "<br />";

<a href="multipage.php">Try Again</a>

</div></body></html>

OUTPUT

Sunday, 1 November 2020

What is Information Security?

Information Security is not only about securing information from unauthorized access. Information Security is basically the practice of preventing unauthorized access, use, disclosure, disruption, modification, inspection, recording or destruction of information. Information can be physical or electronic one.

Monday, 26 October 2020

Write a PHP program to store user registration information (like user name, address, DOB, age, Aadhar card number, gender) with data base and display that details on view screen in tabular manner

user.html

<html>

<head>

<title> user registration information</title>

</head>

<body>

<h3 align="center">user registration information</h3>

<tr>

</tr>

<tr>

<td>Address:</td>

</tr>

<tr>

<td>Date of Birth:</td><td><input type="date" name="dob" id="dob"/></td>

</tr>

<tr>

</tr>

<tr>

<td>Aadhar Number:</td>

</tr>

<tr>

<td>Gender:</td>

<td><input type="radio" name="gender" value="male" /> Male

<input type="radio" name="gender" value="female" /> Female</td>

</tr>

<tr>

</td>

</tr>

</table>

</body>

</html>

storeuser.php

<?php

$link = mysqli_connect("localhost", "root", "", "wit");

// Check connection

if($link === false){

die("ERROR: Could not connect. " . mysqli_connect_error());

}

// Escape user inputs for security

$user = mysqli_real_escape_string($link, $_POST['name']);

$address = mysqli_real_escape_string($link, $_POST['address']);

$dob = mysqli_real_escape_string($link, $_POST['dob']);

$age = mysqli_real_escape_string($link, $_POST['age']);

$aadhar = mysqli_real_escape_string($link, $_POST['aadhar']);

$gender = mysqli_real_escape_string($link, $_POST['gender']);

// attempt insert query execution

$sql = "INSERT INTO storeuser (name, address,dob,age,aadhar,gender) VALUES ('$user', '$address',

'$dob','$age','$aadhar','$gender')";

if(mysqli_query($link, $sql)){

echo "Records added successfully.";

$link_address="store.html";

echo "<a href='".$link_address."'>Go to Register Page</a>";

} else{

echo "ERROR: Could not able to execute $sql. " . mysqli_error($link);

}

// close connection

mysqli_close($link);

<a href="display.php">|Display|</a>

display.php

<html>

<body>

<?php

mysql_connect("localhost","root","");

mysql_select_db("wit");

$r=mysql_query("select * from storeuser");

echo"<table border=1>";

echo"<tr><th>User Name</th><th>Address</th><th>Date of Birth</th><th>Age</th><th>Aadhar Number</th><th>Gender</th></tr>";

while ($row=mysql_fetch_array($r))

{ echo"<tr>";

echo "<td>".$row['0']."</td>"."<td>".$row['1']."</td>"."<td>".$row['2']."</td>"."<td>".$row['3']."</td>"."<td>".$row['4']."</td>"."<td>".$row['5']."</td>";

echo "</tr>";

}

echo"</table>";

</body>

</html>

Monday, 19 October 2020

Write a script that asks the user to enter two numbers and outputs text that displays the sum, product, difference and quotient of the two numbers.

<html>

<head>

<title>javascript using sum, product, difference and quotient</title>

var number1;

var number2;

var sum;

var product;

var difference;

var quotient;

number1 = parseInt(window.prompt( "Enter first number" ));

number2 = parseInt(window.prompt( "Enter second number" ));

sum = number1 + number2;

product = number1 * number2;

difference = number1 - number2;

quotient = number1 / number2;

document.writeln( "<h3>The sum is " + sum + "</h3>" );

document.writeln( "<h3>The product is " + product + "<h3>");

document.writeln( "<h3>The difference is " + difference + "<h3>");

document.writeln( "<h3>The quotient is " + quotient + "<h3>");

</script></head>

</html>

Output:

Sunday, 18 October 2020

Design a form using HTML and java script to collect the details from the user such as name, gender (radio button), address, state & city. Create a dynamic drop down list for state and based on state, create another drop down list containing list of cities for that state.

<html>

<head><title>dynamic drop down list</title>

function dropdownlist()

{

var state=document.getElementById('input').value;

if(state==="AP")

{

var array=["Tirupati","vizag","kadapa","Amaravathi","kurnool"];

}

else if(state==="KA")

{

var array=["Bangalore","Mysore","Mangalore","Hubli"];

}

else if(state==="TN")

{

var array=["vellore","chennai","Coimbatore","Madurai"];

}

else if(state==="TG")

{

var array=["Hyderabad","Warangal","Nizamabad","Karimnagar"];

}

else

{

var array=[];

}

var string='';

for(i=0;i<array.length;i++)

{

string=string+"<option>"+array[i]+"</option>";

}

string="<select name='loc'>"+string+"</select>";

document.getElementById('output').innerHTML=string;

}

</script></head>

<body>

<p>Gender:<input type="radio" name="gender" value="male">Male

<input type="radio" name="gender" value="female">Female</p>

<p>Address:<textarea rows="4" cols="10" placeholder="please enter the proper address"></textarea></p>

<p>

State:

<option>select</option>

</select>

</p>

City:

<option>select</option>

</select>

</div></form></body>

</html>

Output:

Write a script that reads an integer and determines whether it is arm strong number or not.

<html><head><title>Armstrong number or not</title>

function Armstrong()

{

var flag,number,remainder,addition = 0;

number = Number(document.getElementById("num").value);

flag = number;

while(number > 0)

{

remainder = number%10;

addition = addition + remainder*remainder*remainder;

number = parseInt(number/10);

}

if(addition == flag)

{

window.alert("The input number is Armstrong");

}

else

{

window.alert("The input number is not Armstrong");

}

</script></head>

<body>

<h1>Whether a number is Armstrong or not</h1>

Enter the number :<input type="text" name="n" id = "num"/><br/>

</body>

</html>

For example Armstrong numbers are : 153 370 371 407

Output:

Write a PHP script to sort the elements in descending order of an array.

Example 1

<?php

$numbers = array(20, 91, 4, 39, 23);

rsort($numbers);

$arraylength = count($numbers);

for($x = 0; $x < $arraylength; $x++) {

echo $numbers[$x];

echo "<br>";

}

Output:

Example 2

<?php

$cars = array("Maruthi", "TATA", "KIA");

rsort($cars);

$carslength = count($cars);

for($i = 0; $i < $carslength; $i++) {

echo $cars[$i];

echo "<br>";

}

Output:

TATA
Maruthi
KIA

Example 3

<?php

// Define array

$numbers = array(1,2,3,4,5,6,7,8,9,10);

// Sorting and printing array

rsort($numbers); // rsort- sort arrays in descending order

print_r($numbers);

Output:

Array ( [0] => 10 [1] => 9 [2] => 8 [3] => 7 [4] => 6 [5] => 5 [6] => 4 [7] => 3 [8] => 2 [9] => 1 )

Example 4

<?php

$colors = array("Red", "Blue", "Green","Yellow");

rsort($colors);

print_r($colors);

Output: Array ( [0] => Yellow [1] => Red [2] => Green [3] => Blue )

Write a PHP program that receives the value of N using HTML form and displays the first N Fibonacci numbers as HTML list.

<?php

function Fibonacci($num){

if ($num == 0)

return 0;

else if ($num == 1)

return 1;

else

return (Fibonacci($num-1) + Fibonacci($num-2));

}

<html>

<head><title>Fibonacci example</title></head>

Enter Number:<input type="text" name="num"/><br/><br/>

</form>

<?php

if(isset($_POST["print"]))

{

$num = $_POST["num"];

for ($counter = 0; $counter < $num; $counter++){

echo " ".Fibonacci($counter)." ";

}

</body></html>

Thursday, 15 October 2020

Web and Internet Technologies 2 Marks questions and answers

1. What are the different types of lists in HTML?

Ans. unordered list <ul>

ordered list <ol>

Nested list - combination of unordered list and ordered list.

description list - <dl>

2. What is the purpose of meta tags in HTML?

Ans. The <meta> tag defines metadata about an HTML document.

3. What are the different types of Cascading Style Sheets?

Ans. There are three ways of inserting a style sheet are

1. Inline CSS

2. Internal / embedded CSS

3. External CSS

4. What are HTML5 added several new input types?

Ans.

color <input type="color">
date <input type="date">
datetime-local <input type="datetime-local">
email <input type="email">
month
number
range
search
tel
time
url
week

5. What is DTD and types of DTD's?

Ans. A Document Type Definition defines the structure and the legal elements and attributes of an XML document. Two types of DTD's are

1. Internal DTD

2. External DTD

6. What are PHP super global variables?

Ans. The PHP superglobal variables are:

$GLOBALS

$_SERVER

$_REQUEST

$_POST

$_GET

$_FILES

$_ENV

$_COOKIE

$_SESSION

7. What is AJAX?

Ajax stands for Asynchronous JavaScript And XML.

AJAX is not a programming language.

It is a technique for creating better, faster and more interactive web applications with the help of XML, DOM,HTML , CSS and JavaScript.

Unlike classic web pages , which must load in their entirety if content changes.

AJAX allows web pages to be updated asynchronously by fetching data from the server behind the scenes.

AJAX cannot work independently.

AJAX uses a combination of:

1. HTML and CSS for presentation.

2. DOM for dynamic display of and interaction with data.

3. JSON (JavaScript Object Notation)or XML for the interchange of data, and XSLT for its manipulation.

4. XMLHttpRequest object (to exchange data asynchronously with a server)

5. JavaScript.

8. What is Asynchronous in AJAX?

Ans. Asynchronous means that we are exchanging data to/from the server in the background without having to refresh the page.

9. What about the response in AJAX Application?

Responses from the server in AJAX are handled in the form of callbacks.

A callback is a special function which is used in AJAX so that server can respond to the client when it is ready to send data to the client.

10. What are Advantages of AJAX?

AJAX allows web pages to be updated asynchronously by exchanging small amounts of data with the server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.

Bandwidth Usage- Ajax based application use less server bandwidth, because no need to reload complete page.

Asynchronous calls- AJAX make asynchronous calls to a web server. This means client browsers are avoid waiting for all data arrive before start the rendering.

XMLHttpRequest - XMLHttpRequest has an important role in the Ajax web development technique. XMLHttpRequest is special JavaScript object that was designed by Microsoft. XMLHttpRequest object call as a asynchronous HTTP request to the Server for transferring data both side.

11. What are Disadvantages of AJAX?

View source is allowed and anyone can view the code source written for AJAX.

• It can increase design and development time.

• More complex than building classic web application.

• Search Engine like Google cannot index AJAX pages.

• JavaScript disabled browsers cannot use the application.

• Security is less in AJAX application. Anyone can view the source code written for Ajax.

• The back button problem. People think that when they press back button, they will return to the last change they made, but in AJAX this doesn't hold.

12. What is XMLHttpRequest object ?

The XMLHttpRequest object can be used to exchange data with a server behind the scenes. This means that it is possible to update parts of a web page, without reloading the whole page.

13. What are XML Schema built-in data types?

Primitive data types:

String, boolean, decimal, float, double, duration,dateTime, time, date, gYearMonth, gYear, gDay,

gMonthDay, gMonth, hexbinary, base64binary, anyURL, QName, NOTATION.

Derived data types:

normalizedString, token,language,NMTOKEN,NMTOKENS,Name, NCName, ID, IDREF, IDREFS, ENTITY,ENTITIES,integer, nonPostiveInteger, PostiveInteger,NegativeInteger, nonNegativeInteger, unsignedLong,unsignedInt, unsignedShort, unsignedByte,long, int, short, byte.

14. Types of XSD Elements?

Simple Elements

Complex Elements

15. What are Building Blocks of XML Documents?

Seen from a DTD point of view, all XML documents are made up by the following building blocks:

1. Elements

2. Attributes

3. Entities

4. PCDATA

5. CDATA

16. What are XML Schema (XSD) Indicators?

We can control HOW elements are to be used in documents with indicators.

1. <all>

2. <choice>

3. <sequence>

17. Difference between Document Type Definition(DTD) and XML Schema Definition(XSD)?

18. What is XML Schema?

An XML Schema describes the structure of an XML document.

The XML Schema language is also referred to as XML Schema Definition (XSD).

The purpose of an XML Schema is to define the legal building blocks of an XML document:

XML Schema is an XML-based alternative to DTD.

19. What is PCDATA and CDATA?

PCDATA

PCDATA means parsed character data.

Text found between the start tag and the end tag of an XML element.

PCDATA is text that WILL be parsed by a parser. The text will be examined by the parser for entities and markup.

Example

employee.dtd

<!ELEMENT employee (firstname,lastname)>

<!ELEMENT firstname (#PCDATA)>

<!ELEMENT lastname (#PCDATA)>

employee.xml

<?xml version="1.0"?>

<!DOCTYPE employee SYSTEM "employee.dtd">

<firstname>virat </firstname>

<lastname>kohli</lastname>

</employee>

Output: virat kohli

CDATA

CDATA means character data or unparsed character data.

CDATA is text that will NOT be parsed by a parser. Tags inside the text will NOT be treated as markup and entities will not be expanded.

Example

employee.dtd

<!ELEMENT employee (firstname,lastname)>

<!ELEMENT firstname (#CDATA)>

<!ELEMENT lastname (#CDATA)>

employee.xml

<?xml version="1.0"?>

<!DOCTYPE employee SYSTEM "employee.dtd">

<firstname>virat </firstname>

<lastname>kohli</lastname>

</employee>

Output: <firstname>virat </firstname> <lastname>kohli</lastname>

20. What is script manager in AJAX?

The key control in every ASP.NET Ajax-enabled application is the ScriptManager (in the Toolbox’s AJAX Extensions tab), which manages the JavaScript client-side code (called scripts) that enable asynchronous Ajax functionality. A benefit of using ASP.NET Ajax is that you do not need to know JavaScript to be able to use these scripts. The ScriptManager is meant for use with the controls in the Toolbox’s AJAX Extensions tab. There can be only one ScriptManager per page.

21. State the use of WSDL?

WSDL stands for Web Services Description Language

WSDL is used to describe web services

WSDL is written in XML

WSDL is often used in combination with SOAP(Simple Object Access Protocol) and an XML Schema to provide Web services over the Internet. A client program connecting to a Web service can read the WSDL file to determine what operations are available on the server. Any special datatypes used are embedded in the WSDL file in the form of XML Schema.

Write the HTML code to print following table.

<html>

<head><title>table example</title>

<style>

table,th,td{

border: 1px solid black;

}

</style>

</head>

<body>

<table>

<tr>

</tr>

<tr>

<td rowspan="2">THREE</td>

</tr>

<tr>

</tr>

<tr>

<td>SEVEN</td>

<td colspan="2"> EIGHT</td>

</tr>

</table>

</body>

</html>