Design of Multiplayer Games COSC 418 PHP Syntax

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Design of Multiplayer GamesCOSC 418PHP Syntax

• From www.w3schools.com

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PHP Creates HTML Pages

• You cannot view the PHP source code by selecting
  "View source" in the browser - you will only see
  the output from the PHP file, which is plain
  HTML.
• This is because the scripts are executed on the
  server before the result is sent back to the
  browser.

Client HTTP Request
Server HTTP Daemon
PHP Hypertext Preprocessor
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Basic PHP Syntax

• A PHP file normally contains HTML tags, just like
  an HTML file, and some PHP scripting code.
• Below, we have an example of a simple PHP script
  which sends the text "Hello World" to the
  browserlthtmlgt ltbodygt lt?php echo "Hello
  World" ?gt lt/bodygt lt/htmlgt
• A PHP scripting block always starts with lt?php
  and ends with ?gt.

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Basic PHP Syntax

• A PHP scripting block can be placed anywhere in
  the document.
• Each code line in PHP must end with a semicolon.
  The semicolon is a separator and is used to
  distinguish one set of instructions from another.

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PHP Output

• There are two basic statements to output text
  with PHP
• echo
• print
• In the example on the earlier slide we used the
  echo statement to output the text "Hello World".

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Variables in PHP

• All variables in PHP start with a sign symbol.
• Variables may contain strings, numbers, or
  arrays.
• Below, the PHP script assigns the string "Hello
  World" to a variable called txtlthtmlgt ltbodygt
  lt?php txt"Hello World" echo txt ?gt
  lt/bodygt lt/htmlgt

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The Dot . Operator

• To concatenate two or more variables together,
  use the dot (.) operatorlthtmlgt ltbodygt
  lt?php txt1"Hello World"
  txt2"1234" echo txt1 . " " .
  txt2 ?gt lt/bodygt lt/htmlgt
• The output of the script above will be "Hello
  World 1234".

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Comments in PHP

• In PHP, we use // to make a single-line comment
  or / and / to make a large comment
  block.lthtmlgt ltbodygt lt?php //This is a
  comment / This is a
  comment block / ?gt lt/bodygtlt/htmlgt

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PHP Operators

• Arithmetic Operators

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PHP Operators

• Assignment Operators

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PHP Operators

• Comparison Operators

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PHP Operators

• Logical Operators

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PHP Data Types

• Integer
• Double
• String
• Able to reassign type within an expression.
• P. 57
• somevar 1
• somevar 2.67
• somevar 123A String
• x 5 somevar x now equals 128

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Regular Expressions

• A regular expression is a formula for matching
  strings that follow a pattern.
• Used as arguments for many functions.
• grep r.t text.txt

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Forms
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• ltform namenim actionnimparser.php
  methodpostgt
• In the file nimparser.php, it calls it self with
  the form data supplied on the return.
• The form data is available via the _REQUEST
  system array.