/* 一、數組的概述
* 1. 數組的本質:管理和操作一組變量,成批處理
* 2. 數組是複合類型
* 3. 因爲php是弱類型的語言,數組中可以存儲任意長度的數據,也可以存儲任意類型的數據。模擬其他語言的功能。
* 4. 數組就可以完成其它語言數據結構的功能(鏈表, 隊列, 棧, 集合類).所以php開發的很快。
* int a[10]={1,2,3,4,5,6,7,8,9,0};
* 二、數組的分類
* 數組中存有多個單元,(單元稱爲元素)
* 每個元素(下標[鍵]和值)
* 單訪問元素時候,都是通過下標(鍵)來訪問元素
*
* 1. 一維數組, 二維數組, 三維數組 。。。 多維數組
* (數組的數組, 就是在數組中存有其它的數組)
* 2. PHP中有兩種數組
* 索引數組:就是下標是順序整數作爲索引
* 關聯數組:就是下標是字符串作爲索引
*
* 下標(整數, 字符串)只有這兩種
*
* 三、數組多種聲明方式
*
* 1. 直接爲數組元素賦值
a.如果索引下標不給出,就會從0開始順序索引
* b.如果給出索引下標,下一個就會是從最大的開始增1
* c.如果後面出現前面的下標,如果是賦值就是爲前面的元素重新賦值
* d. 混合聲明時,索引和關聯不互相影響(不影響索引下標的聲明)
* 2. 使用array()函數 $a=array("Volvo"=>"XC90","BMW"=>"X5","Toyota"=>"Highlander")關聯數組
$a=array(1,"ligang","hello@ww",33)索引數組
$a=array("id"=>1,"name"=>"zhangsan","age"=>11,100=>"nan","ddd@qq")前三個爲關聯後兩個爲索引
for($i=0;$i<20;$i++)
$a[]=$i;
* 3. 使用其它的函數聲明
* file();
*/
//索引數組
1、、、、、、、、、、、、、、、、、、、、 <?php
$user=array(
array(1,"zhangsan",10,"man"),
array(2,"zhangsan",10,"man"),//訪問10;訪問整條
array(3,"zhangsan",10,"man")
);
echo ($user[1][2]);
echo '<pre>';
print_r($user[1]);
echo '</pre>';
echo '<pre>';
print_r($user);
echo '</pre>';
結果爲:10
Array ( [0] => 2 [1] => zhangsan [2] => 10 [3] => man )
Array ( [0] => Array ( [0] => 1 [1] => zhangsan [2] => 10 [3] => man ) [1] => Array ( [0] => 2 [1] => zhangsan [2] => 10 [3] => man ) [2] => Array ( [0] => 3 [1] => zhangsan [2] => 10 [3] => man ) )
2、、、、、、、、、、、、、、、、、、、、、、、、<?php
$user["id"]=1;
$user["name"]="zhangsan";
$user[]=10;
$user[6]="nan";
$user[]="aaa@cd";
echo '<pre>';//The <pre> tag defines preformatted text.
print_r($user);
echo '</pre>';
print_r(array_keys($user));//返回user的小標的數組
Array ( [0] => 0 [1] => 1 [2] => 2 [3] => 3 )
輸出:
Array ( [id] => 1 [name] => zhangsan [0] => 10 [6] => nan [7] => aaa@cd )
print_r($user);//效果Array( [0] => Volvo [1] => BMW [2] => Toyota)
<?php
$user[]=1;
$user[]="zhangsan";
$user[]=10;
$user[6]="nan";
$user[]="aaa@cd";//注意此處的索引並不是4而是7
Array ( [0] => 1 [1] => zhangsan [2] => 10 [6] => nan [7] => aaa@cd )
echo '<pre>';
print_r($user);
echo '</pre>';
3、、、、、、、、、、、、、、、、、、、、、<?php
$info=array(
"user"=>array(
array(1,"zhangsan",10,"man"),
array(2,"zhangsan",10,"man"),//訪問10;訪問整條
array(3,"zhangsan",10,"man")
),
"score"=>array(
array(1,100,10,23),
array(2,4,10,444),
array(3,55,10,3)
),
"connect"=>array(
array(1,100,"aaa@w"),
array(2,4,"aaa@w"),
array(3,55,"aaa@w")
)
);
echo '<pre>';
print_r($info);
echo '</pre>';
結果
Array ( [user] => Array ( [0] => Array ( [0] => 1 [1] => zhangsan [2] => 10 [3] => man ) [1] => Array ( [0] => 2 [1] => zhangsan [2] => 10 [3] => man ) [2] => Array ( [0] => 3 [1] => zhangsan [2] => 10 [3] => man ) ) [score] => Array ( [0] => Array ( [0] => 1 [1] => 100 [2] => 10 [3] => 23 ) [1] => Array ( [0] => 2 [1] => 4 [2] => 10 [3] => 444 ) [2] => Array ( [0] => 3 [1] => 55 [2] => 10 [3] => 3 ) ) [connect] => Array ( [0] => Array ( [0] => 1 [1] => 100 [2] => aaa@w ) [1] => Array ( [0] => 2 [1] => 4 [2] => aaa@w ) [2] => Array ( [0] => 3 [1] => 55 [2] => aaa@w ) ) )$user[][]=1;
$user[][]=1;
$user[][]=1;
echo '<pre>';
print_r($user);
echo '</pre>';
Array ( [0] => Array ( [0] => 1 ) [1] => Array ( [0] => 1 ) [2] => Array ( [0] => 1 ) )