PHP array definition and traversal, PHP array functions and multi-dimensional arrays

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Release： 2016-07-25 08:51:43

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The definition of PHP array and array traversal, the usage and examples of PHP array functions, PHP array value assignment, the loop output of PHP multi-dimensional array, etc. are provided for your study and reference.

1. PHP array definition and traversal 2. php array function

1. Array definition:

$arr=array(1,2,3);//Index array, all subscripts are numbers $arr=array("name"=>"user1","age"=>"30");//Associative array, the subscript contains letters //There are only two kinds of subscripts, either letters or numbers without double quotes 1,3,"age"=>4,5,100=>6,7,400=>8,9); echo "

";  
print_r ($arr);  
echo "

Copy after login

"; ?>

2. Array subscript: if it is a letter

$arr=array("name"=>1,3,"age"=>4,5,100=>6,7,400=>8,9); //Subscript printing: "name" 0 [name] => 1 [0] => 3 [age] => 4 [1] => 5 [100] => 6 [101] => 7 [400] => 8 [401] => 9

3. Array value: 1. Output the entire array print_r($arr) 2. Output a value in the array

$arr=array("name"=>1,3,"age"=>4,5,"100"=>6,7,"400"=>8,9); echo $arr['age']; echo "
"; echo $arr[100];

3.Array assignment: 1.$arr['age']=30; Array assignment can also define arrays: $arr[]=1; $arr[]=2;

4.Array traversal: 1.for loop

The first ".($i+1)."The individual's name is {$arr[$i]}"; } ?>

Loop plus judgment:

The first ".($i+1)."The individual's name is {$arr[$i]}"; }else{ echo "

th".($i+1)."The individual's name is {$arr[$i]}

"; } } ?>

2.foreach loop foreach performs array traversal:

"; print_r ($arr); echo ""; foreach($arr as $key=>$val){ $num++; if($num%2==1){ echo "

{$key}:{$val}

"; }else{ echo "

{$key}:{$val}

"; } } ?>

3.while....list ..each loop traversal

while(list($key,$val)=each($arr)){ echo $key.$val; } //It is recommended to use foreach to traverse the array

Multidimensional Arrays: 1. One-dimensional array $arr=array(1,2,3); $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:

"; print_r($arr); echo ""; echo "

"; foreach($arr as $val){ if(is_array($val)){ foreach($val as $val2){ echo $val2."
"; } } else{ echo $val."
"; } } ?>

Three-dimensional array value:

"; print_r($arr); echo ""; echo "

"; foreach($arr as $val){ if(is_array($val)){ foreach($val as $val2){ if(is_array($val2)){ foreach($val2 as $val3){ echo $val3."
"; } }else { echo $val2."
"; } } } else{ echo $val."
"; } } ?> //It is recommended to use one-dimensional array and two-dimensional array

A data table is actually a two-dimensional array, and each row of records in it is a one-dimensional array. Query database:

"; print_r($row1); echo ""; ?>

Super global array: superglobal array $_SERVER $_GET $_POST $_REQUEST $_FILES $_COOKIES $_SESSION $GLOBALS $_SERVER View server information

"; print_r($_SERVER); echo ""; ?>

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] => localhost//server domain name [SERVER_ADDR] => 127.0.0.1//Server ip [SERVER_PORT] => 80//Port number [REMOTE_ADDR] => 127.0.0.1 //Client access ip [DOCUMENT_ROOT] => E:/AppServ/www [SERVER_ADMIN] => goxuexi@126.com [SCRIPT_FILENAME] => E:/AppServ/www/index.php //The absolute path of the script file name [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.php//Script name (relative to website root directory) [PHP_SELF] => /index.php [REQUEST_TIME] => 1407568551//Access time [argv] => Array ( ) [argc] => 0 ) $_GET gets the data submitted using get http://localhost/index.php?id=10&name=user1 Communication between two pages: 1. Form value passing The first: get method The second way: post method 2.a tag passing value You can only use the get method The a tag recommends using the get method to submit data. It is recommended to use post method to submit data in forms. magic_quotes_gpc = on; means that when the get request is enabled, the ' in the get data will be preceded by

get instance: index.php

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post实例 $_POST:获取表单post过来的数据

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$_REQUEST 获取a或者表单get或post过来的数据. $_COOKIES 同一个页面在多个页面获取 $_SESSION 同一个变量在多个页面获取到 $_FILES 获取表单中的文件,并生成一个数组. $GLOBALS $GLOBALS[_SERVER] $GLOBALS[_GET] $GLOBALS[_POST] $GLOBALS[_FILES] $GLOBALS[_REQUEST] $GLOBALS[_COOKIES] $GLOBALS[username]//包含页面内的全局变量,并且通过$GLOBALS[username]="user2"改变$username的值.

例子，使用$GLOBALS改变全局变量的值.

"; print_r($GLOBALS); echo ""; ?>