PHP

1
PHP

• Server Side Scripting

2
What is PHP?

• Created by Rasmus Lerdorf in 1994
• Personal Home Pages
• Build extensions to HTML
• Apache Software Foundation project
• PHP Hypertext Preprocessor

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PHP Advantages

• Ease to use
• Procedural language
• Open Source
• Free
• You can add new features
• Multiplatform
• Unix, Windows
• Very popular
• Language support for databases
• MySQL, Informix, Oracle, Sybase, etc.

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Accessing PHP Enhanced HTML Documents

• Client/Server Architecture
• Enter a web address to a PHP file
• Process the request on the Web server
• Receive the file and interpret any HTML in the
  browser

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Basic PHP Development Process

• Create a PHP script and save it to a local disk
• Use FTP to copy file to the server
• Access your file using a browser

6
Embedding PHP Statements within HTML Documents

• lthtmlgt ltheadgtlt/headgt
• ltbodygt
• lth1gtGenerating HTML from PHP lt/h1gt
• lt? Php
• // set up my simple table
• print (Using PHP has ltigtsome advantageslt/igt)
• print (ltulgtltligtSpeedlt/ligtltligt/Ease of uselt/ligt
• ltligtFunctonalitylt/ligtlt/ulgt)
• print (lt/ bodygtlt/htmlgt)
• ?gt

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Results

• Generating HTML from PHP
• Using PHP has some advantages
• Speed
• Ease of Use
• Functionality

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PHP Constructs

• Most statements end with a semi-colon
• PHP commands is case insensitive
• PHP ignores blank spaces
• Comments
• // this is a comment

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PHP Variables

• Used to store and access data
• First character must be a
• Second character alpha or underscore
• Variable names are case sensitive
• first_num 128
• second_num first_num

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Arithmetic Operators

• Addition
• Subtraction
• Division /
• Multiplication
• Remainder
• x 14 3 (x is assigned 2)

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String Variables

• Fname John
• Lname Kerry
• Concatenate Operator
• Name Fname . Lname
• Produces JohnKerry
• Name Fname . . Lname
• Name Fname Lname

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String Functions

• Strlen() returns the length of the string
• num strlen(name)
• Trim() removes any leading/trailing blanks
• StrtoLower StrtoUpper
• All lower case all upper case
• Substr(string, start, how many)
• If how many omitted goes to end of string

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Controlling Script Flow

• If-Then-Else
• Switch
• Loops
• For
• While
• Foreach

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If-Then

• IF statement
• If (average gt 69)
• Grade Pass
• Print (Grade Grade)
• Print Your average was average

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If-Then

• Boolean Operators
• equal to
• ! not equal to
• lt less than
• gt greater than
• gt greater than or equal to
• lt less than or equal to

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String Comparisons

• Strcmp() case sensitive
• Strcsecmp() case insensitive
• num Strcmp(first, second)
• Positive if first gt second
• Negative if first lt second
• Zero if first second

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Else clause

• If (test expression)
• One or more php statements
• else
• one or more php statements

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Elseif

• If (test expression)
• PHP statement(s)
• elseif (test expression)
• PHP statement(s)

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Switch

• Switch (gender)
• Case F
• gender_long female
• Print Your gender is gender_long
• Break
• Case M
• PHP statements
• Break
• Default
• Print Error gender code does not exits

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For-Loop

• For (i 0 ilt max i)
• PHP statements

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While-Loop

• While (counter lt max)
• PHP statements
• counter

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Logical Test Operators

• Two or more Boolean clauses
• and
• or
• ! Not
• While (x lt 100 y lt 300)

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Date Function

• Date()
• Date(D) Mon, Tue, etc
• Date(d) numerical day of the month
• Date(F) month in long format
• Date(M) month in short format
• Date(H) current hour in military format
• See documentation for more

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Arrays

• Sequential Arrays keeps track of data items by
  using sequential numbers
• Associative Array keeps track of data items by
  using character strings
• e.g. fr, so, jr, sr

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Sequential Arrays

• names array(Johnson, Jones, Jackson)
• scores array(66, 75, 80)
• Referencing items
• The first item is number 0
• number scores1
• number scoresi
• Print(names0, names1, names2)

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Loops and Sequential Arrays

• courses array (Perl, PHP, C, Java)
• For (i 0 i lt count(courses) i)
• print (coursesi )
• Foreach (courses as item)
• print (item )

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Adding/Deleting Items

• Array_shift() removes an item from beginning of
  array
• Array_unshift() adds an item to the beginning of
  the array
• Array_unshift(courses,C)
• Array_pop() removes an item from the end of the
  array
• Array_push() adds an item to the end of the array

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Some Useful Array Functions

• Max()
• Min()
• Array_sum()
• Sort()

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Creating Associative Arrays

• instructorScience Jones
• instructorMath Smith
• instructorEnglish Lee
• months array(Jangt31,Febgt28,
• Margt31,Aprgt30)
• days monthMar
• Indices are case-sensitive

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Modifying Associative Items

• Changing a data value
• coursesMath Horn
• Deleting an array item
• Unset(instructorEnglish
• Adding an array item
• coursesPhysics Einstein
• Cant change/rename an index name
• Use delete/add procedures

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Sorting Associative Arrays

• Asort()
• Sorts the pairs on the data values
• Ksort()
• Sorts the pairs on the index values

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Loops and Associative Arrays

• Foreach (courses as index gt item)
• PHP statements
• index pointer
• item value