ITEC106 - SHE

"PHP: Hypertext Preprocessor

PHP is an acronym for

PHP

* widely-used, open-source scripting language
* scripts are executed on the server
* free to download and use

text, HTML, CSS, JavaScript, and PHP code

PHP files can contain 5

server

HTML

PHP code is executed on the ____, and the result is returned to the browser as plain__ ___

.php

PHP files have extension

PHP can generate dynamic page content

PHP can create, open, read, write, delete, and close files on the server

PHP can collect form data

PHP can send and receive cookies

PHP can add, delete, modify data in your database

PHP can be used to control user-access

PHP can encrypt data

What can PHP Do?

1. runs on various platforms (Windows, Linux, Unix, Mac OS X, etc.)
2. compatible with almost all servers used today (Apache, IIS, etc.)
3. supports a wide range of databases
4. is free. Download it from the official PHP resource: www.php.net
5. is easy to learn and runs efficiently on the server side

Why PHP?

HTML

A PHP scripting block always starts with __ __and ends with___.

A PHP scripting block can be placed anywhere in the document.

On servers with shorthand support enabled you can start a scripting block with .

For maximum compatibility, we recommend that you use the standard form (
A PHP file normally contains ____ tags, just like an HTML file, and some PHP scripting code.

echo

PHP has a built-in "_____" function, which is used to output text.

In actuality, it's **not a function; it's a language construct**.

As such, it **does not require parentheses.**

semicolon

Each code line in PHP must end with a ____. The__ ___ is a separator and is used to distinguish one set of instructions from another.

echo and print.

There are two basic statements to output text with PHP:

comment

\

In PHP code, a ____ is a line that is not executed as part of the program.

You can use _____ to communicate to others so they understand what you're doing, or as a reminder to yourself of what you did.

Multi-line

/\* \*/

_______ comments are used for composing comments that take more than a single line.

A _______ comment begins with ____ and ends with ____.

Variables

dollar sign ($)

___ __are used as "containers" in which we store information.__

__A PHP var_____able starts with a__ __*, which is followed by the name of the*__ _______.

1. A variable name must start with a letter or an underscore
2. A variable name cannot start with a number
3. A variable name can only contain alpha-numeric characters and underscores (A- z, 0-9, and _ )
4. Variable names are case-sensitive ($name and $NAME would be two different variables)

Rules for PHP variables:

1. String,
2. Integer,
3. Float,
4. Boolean,
5. Array,
6. Object,
7. NULL,
8. Resource.

8 Variables can store a variety of data types. Data types supported by PHP:

PHP String

– A __*is a sequence of characters, like "Hello world!".*__

__*A*__ *can be any text within a set of single or double quotes.*

*You can join two* ___ together using the dot ( .) concatenation operator.

PHP Integer –

An ____ is a whole number (without decimals) that must fit the following criteria:

It cannot contain commas or blanks;-

It must not have a decimal point;

and It can be either positive or negative.

PHP Float

– A _____, or__ ___-point number, is a number that includes a decimal point.

PHP Boolean

It represents two possible states: TRUE or FALSE.

Operators

_____ carry out operations on variables and values.

Arithmetic Operators

– work with numeric values to perform common arithmetical operations.

modulus operator

The _____ , represented by the % sign, returns the remainder of the division of the first operand by the second operand:

1. modulus operator
2. Addition
3. Subtraction
4. Multiplication
5. Division

5 Arithmetic Operators

Arithmetic Operators

Increment & Decrement Operator

Assignment Operators

Comparison Operators

Logical Operators

5 Operators

Increment & Decrement Operator

– The _______ are used to increment a variable's value. The _______ are used to decrement a variable's value.

post-increment returns the original value before it changes the variable,

pre-increment changes the variable first and then returns the value.

echo $x++; // post-increment echo "
";

echo $x--; // post-decrement echo "
";

echo ++$x; // pre-increment echo "
";

echo --$x; // pre-decrement echo "
";

Increment & Decrement Operator 2 TYPES

Assignment Operators

– used to write/assign values to variables.

Comparison Operators

– compare two values (numbers or strings).

are used inside conditional statements, and evaluate to either TRUE or FALSE.

1. Equal
2. Not equal
3. Greater than
4. Less than
5. Greater than or equal to
6. Less than or equal to

Comparison Operators 6 TYPES

Logical Operators

– are used to combine conditional statements.

and

or

xor

&&

||

!

Logical Operators 6 TYPES

Conditional statements

_____ perform different actions for different decisions.

1. if statement
2. if...else statement
3. if...elseif...else statement
4. switch statement

4 Conditional statements

if statement

Syntax: if (condition) { //code to be executed if condition is true; }

– executes some code if one condition is true

if...else statement

Syntax: if (condition) { //code to be executed if condition is true; } else{ //code to be executed if the condition is false; }

– executes some code if a condition is true and another code if that condition is false.

if...elseif...else statement

ex.


if ($age

– executes different codes for more than two conditions

switch statement

\

$favcolor = "red";

switch ($favcolor) {

case "red":

echo "Your favorite color is red!";

break;

case "blue":

echo "Your favorite color is blue!";

break;

case "green":

echo "Your favorite color is green!";

break;

default:

echo "Your favorite color is neither red, blue, nor green!"; }

//Output Your favorite color is red! ?>

–is an alternative to the if-elseif-else statement. Use the _____ statement to select one of a number of blocks of code to be executed.

default

break

The ____ statement is used if no match is found.

The ___ statement is used to break out of the switch when a case is matched.

If the ____ is absent, the code keeps running.

array

An _____ stores multiple values in one single variable.

Numeric or indexed arrays

Associative arrays

multidimensional arrays

In PHP, there are three kind of arrays:

Numeric or indexed arrays


$myArray\[0\] = "John";

$myArray\[1\] = " PHP ";

$myArray\[2\] = 21;

echo "$myArray\[0\] is $myArray\[2\] and knows $myArray\[1\]";

?> //Output: John is 21 and knows PHP

______ associate a numeric index with their values. The index can be assigned automatically (index always starts at 0), like this:

Associative arrays

\

$people = array("David"=>"27", "Amy"=>"21", "John"=>"42");

// or

$people\['David'\] = "27";

$people\['Amy'\] = "21";

$people\['John'\] = "42"; ?>

\

_____ are arrays that use named keys that you assign to them.

multi-dimensional array

\
2 dimentional array


$people = array( 'online'=>array('David', 'Amy’),

'offline'=>array('John', 'Rob', 'Jack’),

'away'=>array('Arthur', 'Daniel'));

echo $people\['online'\]\[0\] . ' ' . $people\['away'\]\[1\];

?>

//Output

David Daniel

A ___________ contains one or more arrays.

The arrays in the______ can be both numeric and associative.

The dimension of an array indicates the number of indices you would need to select an element.

For a ______array, you need two indices to select an element

For a _______ array, you need three indices to select an element

loops

Often when you write code, you want the same block of code to run over and over again in a row. Instead of adding several almost equal lines in a script we can use _______ to perform a task like this.

while loop

do...while loop

for loop

foreach loop

4 looping statements:

while loop

Syntax:


$i = 1;

while ($i

The_____ executes a block of code as long as the specified condition is true.

do...while loop


$i=5;

do {

echo "The number is ". $i . "
";

$i++;

} while ($i

The ______ will always execute the block of code once, check the condition, and repeat the loop as long as the specified condition is true.

for loop

\

for ($a=0;$a

The ___ is used when you know in advance how many times the script should run.

init:

condition:

increment/decrement:

THE FOR LOOP 3 Parameters:

\
____Initialize the loop counter value

____Evaluates each time the loop is iterated, continuing if evaluates to true, and ending if it evaluates to false

____ Increases the loop counter value

foreach loop

\

$names = array("John", "David","Amy"); foreach($names as $name){

echo $name. "
"; }

?> /\* Output: John David Amy \*/

The _____ works only on arrays, and is used to loop through each key/value pair in an array.

continue statement

When used within a looping structure, the ______ allows for skipping over what remains of the current loop iteration. It then continues the execution at the condition evaluation and moves on to the beginning of the next iteration.

include and require statements

The ___ __&__ _____allow for the insertion of the content of one PHP file into another PHP file, before the server executes it.

require statement

include statement

The _____ is identical to include, the exception being that, **upon failure, it produces a fatal error.**

When a file is included using the______, but PHP is **unable to find it, the script continues to execute.**

In the case of require, the script will cease execution and produce an error.

require

include

Use ____ when the file is required for the application to run.

Use ____ when the file is not required. The application should continue, even when the file is not found.

function

\

function functionName() { //code to be executed } ?>

A _____ is a block of statements that can be used repeatedly in a program.

A _____ will not execute immediately when a page load. It will be executed by a call to the _____.

arguments

Information can be passed to functions through ______, which are like variables.

______ are specified after the function name, and within the parentheses.

You can add as many _____ as you want, as long as they are separated with commas.

parameters

argument

When you define a function, the variables that represent the values that will be passed to it for processing are called _______.

However, when you use a function, the value you pass to it is called an ____.

return statement

A function can return a value using the______. the______ stops the function's execution, and sends the value back to the calling code.

superglobal


1. $_SERVER,
2. $GLOBALS,
3. $_REQUEST,
4. $_POST,
5. $_GET,
6. $_FILES,
7. $_ENV,
8. $_COOKIE,
9. $_SESSION.

A ______ is a predefined variable that is always accessible, regardless of scope.

You can access the PHP _______ through any function, class, or file.

PHP's 9 _______ variables are

$_SERVER

is an array that includes information such as headers, paths, and script locations. The entries in this array are created by the web server.

1. \[‘PHP_SELF‘\]
2. \[‘SERVER_ADDR‘\]
3. \[‘SERVER_NAME‘\]
4. \[‘SERVER_PORT‘\]
5. \[‘HTTP_HOST‘\]
6. \[‘REMOTE_ADDR‘\]
7. \[‘REMOTE_HOST‘\]
8. \[‘REMOTE_PORT‘\]
9. \[‘SCRIPT_FILENAME‘\]
10. \[‘SCRIPT_NAME‘\]
11. \[‘SCRIPT_URI‘\]

$_SERVER 11 main elements

\[‘PHP_SELF‘\]

returns filename of the current executing script

\[‘SERVER_ADDR‘\]

returns ip add of the host server

\[‘SERVER_NAME‘\]

returns the name of the host server

\[‘HTTP_HOST‘\]

returns the Host header from the current request

\[‘REMOTE_ADDR‘\]

returns the ip add where the user is viewing the current page

\[‘REMOTE_HOST‘\]

returns the host name where the user is viewing the current page

\[‘REMOTE_PORT‘\]

returns the port being used on the user’s machine to communicate w/ the web server

\[‘SCRIPT_FILENAME‘\]

returns the absolute path name of the currently executing script

\[‘SERVER_PORT‘\]

returns the port on the server machine being used by the web server for communication (such as 80)

\[‘SCRIPT_NAME‘\]

returns the path of the current script

\[‘SCRIPT_URI‘\]

returns the URI of the current page

$_GET

$_POST

The purpose of the PHP superglobals __ __and__ ____ is to collect data that has been entered into a form.

PHP scripts

The most important thing to notice when dealing with HTML forms and PHP is that any form element in an HTML page will automatically be available to your______

action

The ______ attribute specifies that when the form is submitted, the data is sent to a PHP file named first.php.

$_POST

mwthod = “post'“

The built-in ___ __function is used to collect values from a form sent with__ ____.

Information sent from a form with the ___ __method is invisible to others and has no limits on the amount of information to send.__

___ is the preferred method for sending form data.

when we have an HTML form with the action attribute set to our PHP file, we can access the posted form data using the _____ associative array.

The _____ superglobal array holds key/value pairs.

In the pairs, keys are the names of the form controls and values are the input data entered by the user.

$_GET

mwthod = “get'“

The built-in____ function is used to collect values from a form sent within____.

Information sent from a form with the in____ method is visible to everyone (it will be displayed in the browser's address bar) and has limits on the amount of information to send.

fopen()

The ___ __function creates or opens a file. If you use__ __ with a file that does not exist, the file will be created, given that the file has been opened for writing (w) or appending (a).

1. r
2. w
3. a
4. x
5. r+
6. w+
7. a+
8. x+

Manipulating Files 8 command :

r

Opens file for read only.

w

Opens file for write only. Erases the contents of the file or creates a new file if it doesn't exist.

a

Opens file for write only.

x

Creates new file for write only.

r+

Opens file for read/write.

w+

Opens file for read/write. Erases the contents of the file or creates a new file if it doesn't exist.

a+

Opens file for read/write. Creates a new file if the file doesn't exist

x+

Creates new file for read/write.

fwrite()

string

When writing to a file, use the___ __function.__

__The first parameter of__ __*is the file to write to; the second parameter is the*__ _____ to be written.

fclose()

\\n

The______ function closes an open file and returns TRUE on success or FALSE on failure. It's a good practice to close all files after you have finished working with them.

__The__ _ symbol is used when writing new lines.

a

When appending to a file using the ___ mode, the file pointer is placed at the end of the file, ensuring that all new data is added at the end of the file.

isset()

The ____ function determined whether the form had been submitted, as well as whether the text contained a value. We did not specify an action attribute for the form, so it will submit to itself.

file()

The ____function reads the entire file into an array. Each element within the array corresponds to a line in the file: