PHP Sixth Lesson Array usage

Study Summary:

* Understand the use of basic array functions

* Understand the traversal of arrays

* Understand the basic relationship and use of hyper-global arrays

Array

1. Array definition and traversal
2. Array functions

Array definition:
$arr =array (a);Indexed arrays, subscripts are all numbers
$arr =array ("name" = "user1", "age" = "30");//associative array, subscript contains letters
There are two types of subscripts, either letters, or numbers without double quotes.

<?php$arr=array ("name" =>1,3, "age" =>4,5,100=>6,7,400=>8,9); echo "<pre>";p Rint_r ($arr); echo " </pre> ";? >

Array subscript:
If it's a letter
$arr =array ("name" =>1,3, "age" =>4,5,100=>6,7,400=>8,9);
Subscript Print: "Name" 0
[Name] = 1
[0] = 3
[Age] = 4
[1] = 5
[+] = 6
[101] = 7
[+] = 8
[401] = 9


Array values:
1. Output the entire array

Print_r ($arr)

2. Output a value in the array

$arr =array ("name" =>1,3, "age" =>4,5, "=>6,7", "the" =>8,9 "), Echo $arr [' Age '];echo ' <br> ', Echo $arr [100];

3. Assigning values to arrays:
1. $arr [' Age ']=30;
Array assignment can also define an array:
$arr []=1;
$arr []=2;

4. Array Traversal:
1.for Cycle

<?php$arr[]=1; $arr []=2; $arr []=3; $arr []=4; $arr []=5; $arr []=6; For ($i =0, $i <5; $i + +) {  echo "



Cyclic plus judgment:
<?php$arr[]=1; $arr []=2; $arr []=3; $arr []=4; $arr []=5; $arr []=6; for ($i =0; $i <5; $i + +) {  if ($i%2==0) {echo 


2.foreach Cycle
foreach to iterate through the array:
The <?php//key value pair Name= "user1" is the array subscript and value, key and value$arr[' name ']= "Junzai"; $arr [' Age ']=20; $arr [' Sex ']= ' man '; $arr []= ' abc ' echo "<pre>";p Rint_r ($arr), echo "</pre>", foreach ($arr as $key + $val) {$num ++;if ($num%2==1) {echo " 



3.while....list. Each loop traversal
while (list ($key, $val) =each ($arr)) {
echo $key. $val;
}

We recommend using foreach to iterate through an array

Multidimensional Arrays:
1. One-dimensional array $arr =array (All-round);
$arr [0];
2. Two-dimensional array $arr =array (1,2,array (4,5));
$arr [2][0];
2. Two-dimensional array $arr =array (1,2,array (3,array (4,5));
$arr [2][1][0];


Two-dimensional array traversal:
<?php    Header ("Content-type:text/html;charset=utf-8");        $arr =array ("A", "B", Array ("C", "D"), Array ("E"));        echo "<pre>";p Rint_r ($arr), echo "</pre>", echo "




Three-dimensional array values:
<?php    Header ("Content-type:text/html;charset=utf-8");        $arr =array ("A", "B", Array ("C", "D"), Array ("E", Array ("F", "Z")));        echo "<pre>";p Rint_r ($arr), echo "</pre>", echo "



//recommend using one-dimensional arrays and two-dimensional arrays
A data sheet is actually a two-dimensional array in which each row of records is a one-dimensional array

Querying the database:
<?php    Header ("Content-type:text/html;charset=utf-8");    mysql_connect ("localhost", "root", "1234");    mysql_select_db ("test");    mysql_query ("Set names UTF8");    $sql = "SELECT * from user";        $result = mysql_query ($sql);    $row 1 = mysql_fetch_assoc ($result);        echo "<pre>";    Print_r ($row 1);    echo "</pre>";    ? >





Hyper-Global arrays:
Hyper-Global Array
$_server
$_get
$_post
$_request
$_files
$_cookies
$_session
$GLOBALS

$_server Viewing server information
<?php    Header ("Content-type:text/html;charset=utf-8");        echo "<pre>";    Print_r ($_server);    echo "</pre>";    ? >

apache/2.2.8 (WIN32) php/5.2.6 Server at localhost Port 80




[Server_software] = apache/2.2.8 (Win32) php/5.2.6
[server_name] = localhostServer domain name
[SERVER_ADDR] = 127.0.0.1Server IP
[Server_port] = 80Port number
[REMOTE_ADDR] = 127.0.0.1//Client Access IP
[Document_root] = e:/appserv/www
[Server_admin] = [email protected]
[Script_filename] = e:/appserv/www/index.php//absolute path to the name of the script file
[Remote_port] = 49881
[Gateway_interface] = cgi/1.1
[Server_protocol] = http/1.1
[Request_method] = = GET
[Query_string] =//Request string
[Request_uri] =/Request URL Address
[Script_name] =/index.phpScript name (relative to Web site root directory)
[Php_self] =/index.php
[Request_time] = 1407568551Access time
[argv] = = Array
(
)


[ARGC] = 0
)

$_get get data submitted with get

Http://localhost/index.php?id=10&name=user1

Two pages of communication between:
1. Table only son values
First type: Get mode
Second type: Post mode
2.a Label Transfer value
Can only be used in get mode

A tag recommends using GET method to submit data
The form recommends using post to submit data


MAGIC_QUOTES_GPC = on; indicates that when a GET request is turned on, the ' front plus \ ' In the Get data is spoken.


Get instance:
index.php



rev.php



Post instance
$_post: Get the data from the form POST

index.php



rev.php



$_request
Get the data for a or form get or post.

$_cookies
The same page gets on multiple pages

$_session
The same variable is obtained on multiple pages
$_files
Gets the file in the form and generates an array.

$GLOBALS
$GLOBALS [_server]
$GLOBALS [_get]
$GLOBALS [_post]
$GLOBALS [_files]
$GLOBALS [_request]
$GLOBALS [_cookies]
$GLOBALS [username]//contains global variables within the page and changes the value of $username by $globals[username]= "User2".

Example: Use $globals to change the value of a global variable.


<?php$username111= "User1"; function show () {$GLOBALS [username111]= "USER2";} Show (); Echo $username 111;echo "<pre>";p Rint_r ($GLOBALS); echo "</pre>";? >


Reprint Please specify source: HTTP://BLOG.CSDN.NET/JUNZAIVIP


PHP Sixth Lesson Array usage