Learn PHP with MyAssignmenthelp.net (1)

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• PHP
• (Hypertext Preprocessor)

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Overview of PHP

• PHP stands for Hypertext Preprocessor
• Created by Rasmus Lerdorf in 1995
• It is an open source software
• It is server-side scripting language, like ASP
  and executed on the server
• More functionality added (OOP features), database
  support, protocols and APIs
• A language that combines elements of Perl, C, and
  Java
• It is free to use and download
• PHP files can contain text, HTML tags and scripts
  and file extension of ".php" or ".phtml
• PHP files are returned to the browser as plain
  HTML 

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PHP Syntax

• PHP code is executed on the server, and the plain
  HTML result is sent to the browser.
• Syntax It is starts with lt?php and ends with
  ?gt. A PHP scripting block can be placed anywhere
  in the document.
• Comments in PHP
• use // to make a single-line comment or / and /
  to make a large comment block.

lt?php ?gt
lthtmlgtltbodygtlt?php//This is a comment/ This is a comment block / ?gtlt/bodygtlt/htmlgt
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PHP Language Basics

• Constants, Data Types and Variables
• Constants define a string or numeric value
• Constants do not begin with a dollar sign
• Examples
• define(COMPANY, Acme Enterprises )
• define(YELLOW, FFFF00)
• define(PI, 3.14)
• define(NL, ltbrgt\n)
• Data types
• Integers, doubles and strings
• isValid true // Boolean
• 25 // Integer
• 3.14 // Double
• Four // String
• Total value // Another string

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Variables

• It is used to store information.
• It is used for storing information, like text
  strings, numbers or arrays.
• All variables in PHP start with a sign symbol.
• The declaring a variable
• String variable
• used to store and manipulate text
• script assigns the text "Hello" to a string
  variable called text

var_name value
lt?phptextWelcome"echo text?gt
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Operators

• Arithmetic Operators
• (Addition), - (Subtraction),
  (Multiplication), / (Division), (Modulus
  ), (Increment), -- (Decrement)
• Assignment Operators
• , , -, , /, .,
• Comparison Operators
• , !, ltgt, gt, lt, gt, lt
• Logical Operators
• (and), (or), ! (not)

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Conditional Statements

• if Statement
• execute some code only if a specified condition
  is true
• if...else Statement
• execute some code if a condition is true and
  another code if the condition is false
• if...elseif....else Statement
• use this statement to select one of several
  blocks of code to be executed

if (condition) code to be executed if condition is true
if (condition)  code to be executed if condition is trueelse   code to be executed if condition is false
if (condition)   code to be executed if condition is true elseif (condition)   code to be executed if condition is true else   code to be executed if condition is false
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Switch Statement

• Conditional statements are used to perform
  different actions based on different conditions.
• Syntax

switch (n)case label1  code to be executed if nlabel1  breakcase label2  code to be executed if nlabel2  breakdefault  code to be executed if n is different from both label1 and label2
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Loops

• while Loop
• executes a block of code while a condition is
  true.
• do...while Statement
• always execute the block of code once, it will
  then check the condition, and repeat the loop
  while the condition is true.

while (condition)    code to be executed 
do    code to be executed  while (condition)
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Loops (cont)

• for Loop
• The for loop is used when you know in advance how
  many times the script should run.
• foreach Loop
• The foreach loop is used to loop through arrays.

for (init condition increment)    code to be executed 
foreach (array as value)    code to be executed 
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Form

• One of the main features in PHP is the ability to
  take user input and generate subsequent pages on
  the input. In this page, we will introduce the
  mechanism by which data is passes in PHP.
• Let's consider the following two files
• query.php
• result.php

ltform actionresult.php typepostgt ltinput typetext nameemployeegt ltinput typesubmit valueSubmitgt lt/formgt
lt?php employee_name_POST"employee" print employee_name ?gt
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_GET Function

• The built-in _GET function is used to collect
  values in a form with method"get".
• When using method"get" in HTML forms, all
  variable names and values are displayed in the
  URL.
• Information sent from a form with the GET method
  is visible to everyone and has limits on the
  amount of information to send.
• When the user clicks the "Submit" button, the URL
  sent to the server could look something like
  this

ltform actionform.php" method"get"gtName ltinput type"text" name"name" /gtAge ltinput type"text" name"age" /gtltinput type"submit" /gtlt/formgt
http//www.xyz.com/form.php?nameDennyage20
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_POST Function

• The built-in _POST function is used to collect
  values from a form sent with method"post".
• Information sent from a form with the POST method
  is invisible to others and has no limits on the
  amount of information to send and the variables
  are not displayed in the URL and 8 Mb max size
  for the POST method, by default also can be
  changed by setting the post_max_size in the
  php.ini file.
• Information sent from a form with the POST method
  is invisible to others and has no limits on the
  amount of information to send.

ltform actionform.php" method"post"gtName ltinput type"text" name"name" /gtAge ltinput type"text" name"age" /gtltinput type"submit" /gtlt/formgt
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Thank You
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