PHP

What is it?

PHP is a server scripting language.
It is used for making dynamic and interactive Web pages.
PHP stands for Hypertext Pre-processor.
Both PHP and JavaScript can be embedded into HTML pages.

Wha is a PHP file?

PHP file extension is ".php"
A PHP file can contain text, HTML, CSS, JavaScript, and PHP code.
It executed on the server.
The result is returned to the browser as plain HTML.
A script is a set of programming instructions that are interpreted at runtime.
The purpose of the scripts is usually to enhance the performance or perform routine tasks for an application.
PHP is a case-sensitive language, “VAR” is not the same as “var”.

Why PHP?

Runs PHP file extension is ".php"
A PHP file can contain text, HTML, CSS, JavaScript, and PHP code.
It executed on the server.
The result is returned to the browser as plain HTML.

What is XAMPP?

XAMPP is an open source cross-platform web server,
It contains MySQL database engine, and PHP and Perl package.
It is compiled and maintained by apache.

X A M P P

cross-platform operating systems

Apache

MySQL

PHP

Perl

XAMPP deals with all the complexity in setting up and integrating with Apache, PHP, MySQL, and Perl.

Why use XAMPP?

In order to use PHP, you will need to install PHP, Apache and maybe even MySQL.
It’s not easy to install Apache and configure it.
XAMPP deals with all the complexity in setting up and integrating with PHP and Perl.
Unlike JAVA, PHP needs a web server to work.
XAMPP provides an easy to use the control panel to manage:

How to Download and Install XAMPP?

Here are the steps to install XAMPP for Windows.
Download the XAMPP installer here. https://www.apachefriends.org/download.html
If you are getting a warning message "Important! Because of an activated User Account Control (UAC) on your system".
Make sure you deactivate the UAC feature.
To do this, Select Control Panel > User Account > Change Access Control setting > Set the meter as lowest > OK.

In the next screen, Change the installation path if required. Click Next.
In the next screen select Apache and MySQL.
Before we test our XAMPP installation, let’s first look at the basic directories that we will be working with.

mysql: This directory contains all the information related to MySQL database engine, by default port no. 3306.

htdocs: This is the web root directory. All of our PHP codes will be placed in this directory

php: This directory contains PHP installation files. This directory is used to configure how PHP behaves on your server.

Start the XAMPP Control Panel, which looks like a below pic.
Apache, MySQL server and Tomcat service have been installed.
Green highlight represents, Apache has started.
Red highlight represents, here MySQL and Tomcat has not started, they got some issue.

Look at the basic configurations required before we start using our XAMPP installation for developing PHP powered websites.
Type the URL http://localhost/xampp/ in your favorite browser.

Hello PHP Program

<!DOCTYPE html>
<html>
<body>

<?php
echo "My first PHP script!";
?>

</body>
</html>

Here I installed Adobe Dreamweaver IDE, where I will keep the php and HTML coding.
The below screenshot of Dreamweaver IDE, and the Hello PHP program.

Output on Browser

PHP code in editor

Setup PHP on IIS (Internet Information Services)

If you have an issue with XAMPP server.
You can setup PHP on IIS, a Windows application.
Download PHP package form here, https://windows.php.net/download#php-7.2 .
Extract the zip file > Rename the folder to PHP > Keep that folder on C.

Keep PHP folder on C drive

Change the file name; php.ini.production to php.ini > Save.

Rename the file as php.ini

Open that file (php.ini) in notepad.
Find extension_dir = , set the value as "c:\php\ext".
Remove ; or semicolon before 3 parameters; extension_dir, cgi.force_redirect, & fastcgi.impersonate.
Save that file.

Open IIS (Internet Information Services).
Click on Default Document on IIS > Open feature > Add > index.php > OK.
Click on Directory Browsing > Open feature > Enable.
Click on FastCGI Setting > Open feature > Add Application > set full path "c:\php\php-cgi.exe" > Open > OK.
Click on Handler Mapping > Open feature > Add Module Mapping > set the followings.
Request path: *php
Module: FastCGIModule
Executable: php.cgi.exe
Name: PHP
Save
Restart the server.
Create a new site > set a physical path where the PHP pages we will make.

Add some features

Type a hello PHP code > save as .php > in D:\\PHP folder.
Open browser > type localhost/php
Here are our hello php page looks in a browser.

PHP Data Types

A datatype is the classification of data into a category according to its attributes.
A variable is a name given to a memory location that stores data at runtime.

String
Integer
Float
Boolean
Array
Object

PHP determines the data type depending on the attributes of the supplied data.

Variable Initialization Rules

A Php global variable is accessible to all the scripts in an application.
A local variable is only accessible to the script that it was defined in.
All variable names must start with the dollar sign ( $ ).
eg. $var, $var1, $var_one, etc.
Here are some rule followed when creating variables.
All variables names must start with a letter followed by other characters.
Variable must not contain space.
We can not use dollar ( & ) or minus sign( - ) to separate variable names.

Correct way of defining variable

Incorrect way of defining variable

Integer numbers

Floating point numbers

Character strings

Character strings

Array of String

Variable Type Casting

Typecasting is converting a variable or value into the desired data type.
This is very useful when performing arithmetic computations that require variables to be of the same data type.
Typecasting in PHP is done by the interpreter.
The var_dump function is used to determine the data type

PHP Constant

A constant is a variable whose value can not be changed at runtime.
We can a value to a variable, that never chages.
Syntax: define ( 'PI' , 3.14 ) ;
It creates a constant with a value of 3.14.
We can not assign a different value.

PHP Arithmatic Operator

Arithmetic operators are used to performing arithmetic operations on numeric data.
The concatenate operator works on strings values too.
PHP supports the following operators.

PHP Assigning Operator

Assignment operators are used to assigning values to variables.
They can also be used together with arithmetic operators.

PHP Comparison Operator

Comparison operators are used to compare values and data types.

PHP Logical Operator

Logical operators are used to compare conditions or values.
When working with logical operators, any number greater than or less than zero (0) evaluates to true.
Zero (0) evaluates to false.

Comments

Commenting the source code helps remember what the code does.
Can be easily understood by other developers by simply reading the comments.
Single line comments start with double forward slashes // and they end in the same line.
Multiple line comments start with a forward slash followed by the asterisk /* and end with the asterisk followed by the forward slash */.

Include/Include_once

The “include” php statement is used to include other files into a PHP file.
It has two variations, include and include_once.
Include_once is ignored by the PHP interpreter if the file to be included.

Require/Require_once

The require/require_once statement is used to include file.
Require_once is ignored if the required file has already been added by any of the four include statements.

PHP Array

An array is a special variable, which can hold more than one value at a time.
We can access the values by referring to an index number.
In PHP, the array() function is used to create an array.
Here, the array is of 3 types.

PHP Array

Indexed Array

Arrays with a numeric index.

Associative Array

Arrays with named keys.

Multi-dimensional Array

Arrays containing one or more arrays.

Indexed Array

The index can be assigned automatically (index always starts at 0).
Or the index can be assigned manually.
count() function is used to know the length of the array.

Associated Array

Information can be passed to functions through arguments. An argument is just like a variable.
The following example has a function with two arguments ($fname and $year):

Multi-Dimensional Array

A multidimensional array is an array containing one or more arrays.
The dimension of an array indicates the number of indices you need to select an element.
PHP understands multidimensional arrays that are two, three, four, five, or more levels deep.
For a two-dimensional array, you need two indices to select an element.
For a three-dimensional array, you need three indices to select an element.
The advantage of multidimensional arrays is that they allow us to group related data together.

There are lots of built-in functions in PHP.
This allows to access and manipulate the arrays.
Arrays easily help group related information such as server login details together.

PHP Functions

We can create a function.
PHP allows us to reuse the code over and over again.
A function will be executed by a call to the function.
Function names are NOT case-sensitive.
It has more than 1000 built-in functions.

Syntax:

function addNumbers ( $num1 , $num2 ){

return num1 + $num2 ;

}

echo " 3 _+ 4 = " . addNumber ( 3 , 4 );

Functions Arguments

Information can be passed to functions through arguments. An argument is just like a variable.
The following example has a function with two arguments ($fname and $year):

Function with Default Argument Value

If we call the function without arguments it takes the default value as an argument

Function with Returning values

To let a function return a value, use the return statement.

Mathematical Functions

The math functions can handle values within the range of integer and float types.
The PHP math functions are part of the PHP core.
There are a number of functions available related to numerical and mathematical.
We cover some important functions.

PHP String

A string is a collection of characters, can contain alphanumeric characters.
It is one of the data types supported by PHP.
Strings are created when;

We declare variable and assign string characters to it.
Use them with echo statement.

Create Stings

The simplest way to create a string is to use single quotes.
The double quotes are used to create relatively complex strings compared to single quotes.
Variable names can be used inside double quotes and their values will be displayed.
To show any character like ' , " , \ or any character, use the backslash " \ " before character.

PHP Heredoc

Heredoc method is used to create string values.
You can also use double quotes inside without escaping them.
<<<EOT (end of the text) is the string delimiter.

PHP Nowdoc

Nowdoc is an identifier with a single quote string.
No parsing is done inside a Nowdoc.
Nowdoc is supported only by PHP 5.3.
Can not pass the variable.

strstr ( $randString, 'Ravi' ); This function searches for the occurrence of a string inside another string. It returns the rest of the string (from the matching point), or FALSE, if the string to search for is not found.

PROGRAM 2

Write a program to count the no. of occurrence of the substring in a bigstring.
Here the full string is $i, and the substring is $subString.
The output is 4.

Conditional Execution

Conditional statements are used to perform different actions based on different conditions.
In PHP we have the following conditional statements:

if statement - executes some code if one condition is true.
if...else statement - executes some code if a condition is true and another code if that condition is false.
if...elseif....else statement - executes different codes for more than two conditions.
switch statement - selects one of many blocks of code to be executed.

IF statement

You have a block of code that should be executed only if a certain condition is true

IF...ELSE statement

ou have two options, and you have to select one.

IF...ELSEIF...ELSE statement

when you have to select more than two options and you have to select one or more

SWITCH statement

Switch… case is similar to the if then… else control structure.
It only executes a single block of code depending on the value of the condition.
If no condition has been met then the default block of code is executed.

Loop Execution

Conditional statements are used to perform different actions based on different conditions.
In PHP we have the following conditional statements:

Loop Types

FOR

for..each

WHILE

while

do...while

for

FOR loop

For loops execute the block of code a specified number of times.
In for loop syntax, there are 3 factors are there:

initialize: usually an integer.
condition: if the condition is true, the loop continues.
increment: increment the value of an integer.

FOR...EACH loop

Foreach loop is used to iterate the array values.

Another example for an associative array.
Here we declare key and value as a variable & use them.
An associative array uses alphanumeric words for access keys and value.

WHILE loop

It is used to execute a block of code a repeatedly until the set condition gets satisfied.
In While loop, it checks the condition first. If it evaluates to true, the block of code is executed as long as the condition is true.

DO...WHILE loop

Here it executes the block of code at least once before evaluating the condition

Reading Files into a String or Array

Here we will see how to read/write a file.
There are some funtion in PHP, which allows us to work with an entire file as a single variable.

There are several ways for reading a file.

Method 1

Include or Requre puts the content of the specified file directly into the current file as if you had typed it yourself.

include 'myfile.txt';

Method 2

Open a connection to a file, using fopen( ).
Work with that file line by line before you close the resource.
Funtions for reading each line are fgetc, fgets, fgetss, fread, and fwrite.

if ( $fh = fopen ( 'mytext.txt' , 'r' ) ) {
while ( !feof ( $fh) ) {
$line = fgets ( $fh ) ;
echo $line ;
}
fclose ( $fh ) ;
}

Method 3

Read the entire file into a string using file_get_contents.

$file = file_get_contents ( 'myfile.txt' ) ;
echo $file ;

Method 4

Read the entire file into an array of lines using file.

$file_lines = file ( 'mytext.txt' ) ;
foreach ( $file_lines as $line ) {
echo $line ;
}

Write a File

The fopen() function is also used to create a file.
Here is an example of PHP (writeFile.php) for writing data to a text file.

Cookies

A cookie is a small file, that the web server stores on the client computer.
Once the cookie has been set, all page requests that follow return the cookie name and value.
Maximum size: 4kb.
A cookie created by a user can only be visible to them.
Other users cannot see its value.
The web browser has option for disabling cookies & third party cookies.

Why Cookies

Tracks the states of the application.
Personalize the user experience.
Tracking the pages visited by a user.

Creating Cookies

In PHP, setcookie() is a function used to create a cookie.
$_COOKIE is array variable, the server uses for retrieving its value.
Syntax: setcookie(cookie_name, cookie_value, [expiry_time], [cookie_path], [domain], [secure], [httponly]);

Retriving Cookies Value

$_COOKIE is used to retrieve data.
To show the content of the cookie array variable, syntax: print($_COOKIE);
The default size of the cookie is 1 GB, can be changed in the php.ini file.

Delete Cookies

To destroy a cookie before its expire time, we can set a expire time with negative (-ve) sign.
Syntax: setcookie("user_name", "Tom", time() -3600, ' / ');

Session

A Session is a global variable stored on the server.
Each session is assigned a unique id which is used to retrieve a value.
Session id is stored in a $_COOKIE global array variable & $_SESSION.
We can store important user data in the session.
Here is the syntax of creating & destroying the session.

PHP & MySQL Database

With PHP, we can connect to a database and manipulate the database.
MySQL is the most popular database used with PHP.
The data in a MySQL database are stored in tables.
A table is a collection of related data, it consists of rows and columns.

insert & retrieve data

.php file

MySQL Database

PHP 5 and later works with a MySQL database using:

MySQLi extension( i mens improved)
PDO (PHP Data Objects)

MySQLi extension

PDO

PDO works on 12 different database systems.
If you change the database, you need to change the connection string.

It works with only MySQL database.
To change any other DB, need to rewrite entire code.

We will work with the MySQLi extension and MySQLi procedural
For Linux and Windows: The MySQLi extension is automatically installed in most cases, when php5 MySQL package is installed.
Here some predefined function for mysql database.

To Open a Connection

We will work with the MySQLi extension.
For Linux and Windows: The MySQLi extension is automatically installed in most cases, when php5 MySQL package is installed.
If you get error regarding password, execute this: ALTER USER 'yourusername'@'localhost' IDENTIFIED WITH mysql_native_password BY 'youpassword';

To Create a Table

Here we will create a table Employee, with five column: id, firstname, lastname, email & mobile no.

To Insert a Table

A prepared statement is a feature used to execute the same (or similar) SQL statements repeatedly with high efficiency.

To Select a Table

The following example selects the id, firstname, last name from Employee table & displays it on the page.

Reading from Form

PHP can read from a browser through a HTML form.
PHP $_POST['variable_name'] & $_GET('variable_name') holds the form data, are global variable.
The isset () function is used to check whether a variable is set or not.

Program 2

Find the permutation of a string, "ab".
Ans. ab, ba

Program 3

Find Digit Identification if Sting have any number.
Input: Stone123Profits
Output: True

Program 4

Find & replace the 1st highest repeated character with user given character.
Input: acbabcabc, replace with: z
Output: zvczbczbc

Program 5

WAP to print a Numerical Diamond Pattern.
Input: 5
Output: Prints diamond pattern

For upper pyrimid

For reverse pyrimid

Here is the output Diamond Pattern on the browser.

Program 6

Get the numbers from a String & Sum those numbers.
Input: Stone123Profits7
Output: 123 + 7 = 130

On the browser, the output is here.

Program 7

Inter data into Database & retrive form database.
Input: Stone123Profits7
Output: 123 + 7 = 130

Exercise 2

Cont the number of occurrences of a substring in a full String.
Input: fullsring- abcdabegabchj , subsring- abc
Output: 2 times

Here is the output on the browser.
It will search for a substring & count its occurrences on a full string.

Exercise 3

Ask username & his age, then write a sentence.
Input: Ravi, 18
Output: Ravi is 18 years old.

Exercise 4

Read from a file & write to a file. Read the 2nd & 4th line in a file.
Input:
Output:

Exercise 5

Count the number of occurrences of "Ravi" & replace with "Chandu".
Input:
Output:

Exercise 6

Draw Line, Circle, Rectangle & Star.
Input: N/A
Output: Geometric Shapes

To work with image file & shapes in PHP, we need to add GD library.
To configure this setting, go to C:\\php\php.in
Open php.in file > find gd2 > chage the extension value to php_gd2.dll

add php_gd2.dll

& remove ":"

We use some image function from PHP GD library.

No. of planes

R G B

Point 2 (x,y)

Point 1 (x,y)

The shapes are showing in the browser.

Exercise 7

WAP to write an excel data to the database.
Input: excel file
Output: Data into a database

PHP

What is it?

PHP is a server scripting language.

It is used for making dynamic and interactive Web pages.

PHP stands for Hypertext Pre-processor.

Both PHP and JavaScript can be embedded into HTML pages.

Wha is a PHP file?

PHP file extension is ".php"

A PHP file can contain text, HTML, CSS, JavaScript, and PHP code.

It executed on the server.

The result is returned to the browser as plain HTML.

A script is a set of programming instructions that are interpreted at runtime.

The purpose of the scripts is usually to enhance the performance or perform routine tasks for an application.

PHP is a case-sensitive language, “VAR” is not the same as “var”.

Why PHP?

Runs PHP file extension is ".php"

A PHP file can contain text, HTML, CSS, JavaScript, and PHP code.

It executed on the server.

The result is returned to the browser as plain HTML.

What is XAMPP?

XAMPP is an open source cross-platform web server,

It contains MySQL database engine, and PHP and Perl package.

It is compiled and maintained by apache.

X A M P P

cross-platform operating systems

Apache

MySQL

PHP

Perl

XAMPP deals with all the complexity in setting up and integrating with Apache, PHP, MySQL, and Perl.

Why use XAMPP?

In order to use PHP, you will need to install PHP, Apache and maybe even MySQL.

It’s not easy to install Apache and configure it.

XAMPP deals with all the complexity in setting up and integrating with PHP and Perl.

Unlike JAVA, PHP needs a web server to work.

XAMPP provides an easy to use the control panel to manage:

How to Download and Install XAMPP?

Here are the steps to install XAMPP for Windows.

Download the XAMPP installer here. https://www.apachefriends.org/download.html

If you are getting a warning message "Important! Because of an activated User Account Control (UAC) on your system".

Make sure you deactivate the UAC feature.

To do this, Select Control Panel > User Account > Change Access Control setting > Set the meter as lowest > OK.

In the next screen, Change the installation path if required. Click Next.

In the next screen select Apache and MySQL.

Before we test our XAMPP installation, let’s first look at the basic directories that we will be working with.

mysql: This directory contains all the information related to MySQL database engine, by default port no. 3306.​​

htdocs: This is the web root directory. All of our PHP codes will be placed in this directory

php: This directory contains PHP installation files. This directory is used to configure how PHP behaves on your server.

Start the XAMPP Control Panel, which looks like a below pic.

Apache, MySQL server and Tomcat service have been installed.

Green highlight represents, Apache has started.

Red highlight represents, here MySQL and Tomcat has not started, they got some issue.

Look at the basic configurations required before we start using our XAMPP installation for developing PHP powered websites.

Type the URL http://localhost/xampp/ in your favorite browser.

Hello PHP Program

<!DOCTYPE html> <html> <body> <?php echo "My first PHP script!"; ?> </body> </html>

Here I installed Adobe Dreamweaver IDE, where I will keep the php and HTML coding.

The below screenshot of Dreamweaver IDE, and the Hello PHP program.​

Output on Browser

PHP code in editor

Setup PHP on IIS (Internet Information Services)

If you have an issue with XAMPP server.

You can setup PHP on IIS, a Windows application.

Download PHP package form here, https://windows.php.net/download#php-7.2 .

Extract the zip file > Rename the folder to PHP > Keep that folder on C.

Keep PHP folder on C drive

Change the file name; php.ini.production to php.ini > Save.​

Rename the file as php.ini

Open that file (php.ini) in notepad.

Find extension_dir = , set the value as "c:\php\ext".

Remove ; or semicolon before 3 parameters; extension_dir, cgi.force_redirect, & fastcgi.impersonate.

Save that file.

Open IIS (Internet Information Services).

Click on Default Document on IIS > Open feature > Add > index.php > OK.

Click on Directory Browsing > Open feature > Enable.

Click on FastCGI Setting > Open feature > Add Application > set full path "c:\php\php-cgi.exe" > Open > OK.

Click on Handler Mapping > Open feature > Add Module Mapping > set the followings.

Request path: *php

Module: FastCGIModule

Executable: php.cgi.exe

mysql: This directory contains all the information related to MySQL database engine, by default port no. 3306.

<!DOCTYPE html>
<html>
<body>

<?php
echo "My first PHP script!";
?>

</body>
</html>

The below screenshot of Dreamweaver IDE, and the Hello PHP program.

Change the file name; php.ini.production to php.ini > Save.