PHP Lesson 6 Usage of Arrays_PHP Tutorial

PHP Lesson 6 Usage of Arrays

Learning Summary:

* Understand the use of basic array functions

*Understand array traversal

*Understand the basic relationship and use of superglobal arrays

Array

1. Array definition and traversal
2. Array function

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

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

"; ?>


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


Array value:
1. Output the entire array

print_r($arr)

2. Output a certain value in the array

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

<?php
	
	
				$arr[]=1;
				$arr[]=2;
				$arr[]=3;
				$arr[]=4;
				$arr[]=5;
				$arr[]=6;
				
				
			 	for($i=0;$i<5;$i++){
			 		
			 		echo "<h1 id="第-i-个人的名字是-arr-i">第".($i+1)."个人的名字是{$arr[$i]}</h1>";
			 	
			 	}
				?>

Loop plus judgment:

	<?php
	
	
			$arr[]=1;
			$arr[]=2;
			$arr[]=3;
			$arr[]=4;
			$arr[]=5;
			$arr[]=6;
			
			
		 	for($i=0;$i<5;$i++){
		 		
		 		if($i%2==0){
		 				echo "<h1 id="第-i-个人的名字是-arr-i">第".($i+1)."个人的名字是{$arr[$i]}</h1>";
		 		}else{
		 			echo "<h1 id="第-i-个人的名字是-arr-i">第".($i+1)."个人的名字是{$arr[$i]}</h1>";
		 		}
		 	
		 	}
			?>

2.foreach loop
foreach performs array traversal:

<?php
	
			//键值对 name="user1" 就是数组下标和值,key和value
			
			$arr[&#39;name&#39;]="junzai";
			$arr[&#39;age&#39;]=20;
			$arr[&#39;sex&#39;]="man";
			$arr[]="abc";


			echo "<pre class="code">";	
			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 array:
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:

<?php
	
			    header("content-type:text/html;charset=utf-8");
			    
			    $arr=array("a","b",array("c","d"),array("e"));
			    
			    echo "<pre class="code">";
				
				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:

<?php
	
			    header("content-type:text/html;charset=utf-8");
			    
			    $arr=array("a","b",array("c","d"),array("e",array("f","z")));
			    
			    echo "<pre class="code">";
				
				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:

<?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);
			    $row1 = mysql_fetch_assoc($result);
			    
			    echo "<pre class="code">";
			    print_r($row1);
			    echo "

"; ?>




Super global array:
Superglobal array
$_SERVER
$_GET
$_POST
$_REQUEST
$_FILES
$_COOKIES
$_SESSION
$GLOBALS

$_SERVER View server information

<?php
	
				    header("content-type:text/html;charset=utf-8");
				    
				    echo "<pre class="code">";
				    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 Get the data submitted with get

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

Communication between two pages:
1. Form value
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


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

<html>
				<head> 
				<title>
				接收信息
				</title>
				</head>
				<body>
				junjun2<br>
				junzai3<br>
				junjun4<br>
				junjun5<br>
				</body>
				
			</html>

rev.php

<html>
					<head> 
					<title>
					接收信息
					</title>
					</head>
					<body>
					<h1>欢迎:
					<?php echo $_GET[&#39;name&#39;];?>
					</h1>
					<hr>
					<h1 id="姓名-php-echo-GET-name">姓名:<?php echo $_GET[&#39;name&#39;]?></h1>
					<h1 id="年龄-php-echo-GET-age">年龄:<?php echo $_GET[&#39;age&#39;]?></h1>
					</body>
					
					</html>

post实例
$_POST:获取表单post过来的数据

index.php

<html>
				<head> 
				<title>
				接收信息
				</title>
				</head>
				<body>
				<h1 id="提交用户信息">提交用户信息</h1>
				 
				</body>
				
			</html>

rev.php

<html>
					<head> 
					<header content-type="text/html";charset="gbk">
					<title>
					接收信息
					</title>
					</head>
					<body>
					<h1>欢迎:
					<?php echo $_POST[&#39;name&#39;];?>
					</h1>
					<hr>
					<h1 id="姓名-php-echo-POST-name">姓名:<?php echo $_POST[&#39;name&#39;]?></h1>
					<h1 id="年龄-php-echo-POST-age">年龄:<?php echo $_POST[&#39;age&#39;]?></h1>
					</body>
					
				</html>

$_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]
$GLOBALS[username]//里面包含页面内的全局变量,并且通过$GLOBALS[username]="user2"改变$username的值.

实例:使用$GLOBALS改变全局变量的值.

<?php
					$username111="user1";
					
					function show(){
					$GLOBALS[username111]="USER2";
					}
					
					show();
					
					echo $username111;
					
					echo "<pre class="code">";
					print_r($GLOBALS);
					echo "

"; ?>

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