PHP學習随筆(3):數組

三種數組類型:

　　1.數值數組:帶有數字id鍵的數組

　　2.關聯數組:數組中的每個id鍵關聯一個值

　　3.多元數組:包含一個或多個數組的數組

數值數組

　　數值數組存儲的每個元素有帶有一個數字id鍵(索引?)

　　建立數值數組的兩種方法:

$names = array("Peter","Quagmire","Joe");      

$names[0] = "Peter";
$names[1] = "Quagmire";
$names[2] = "Joe";      

　　以上代碼都可以建立數值數組,下面是在腳本中使用這些id

<?php

$names[0] = "Peter";
$names[1] = "Quagmire";
$names[2] = "Joe";

echo $names[1] . " and " . $names[2] . " are ". $names[0] . "'s neighbors";
?>      

　　輸出結果:

Quagmire and Joe are Peter's neighbors      

關聯數組

　　通過關聯數組,我們可以把值作為鍵,并向它們指派(類似于C#中的字典集合)

　　下面為關聯數組的建立方法

$ages = array("Peter"=>32, "Quagmire"=>30, "Joe"=>34);      

$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";      

　　在腳本中使用

<?php

$ages['Peter'] = "32";
$ages['Quagmire'] = "30";
$ages['Joe'] = "34";

echo "Peter is " . $ages['Peter'] . " years old.";
?>      

　　輸出結果

Peter is 32 years old.      

多元數組

　　在多元數組中,每個元素的值都是一個數組,以次類推

$families = array
(
  "Griffin"=>array
  (
  "Peter",
  "Lois",
  "Megan"
  ),
  "Quagmire"=>array
  (
  "Glenn"
  ),
  "Brown"=>array
  (
  "Cleveland",
  "Loretta",
  "Junior"
  )
);      

　　輸出一個值

echo "Is " . $families['Griffin'][2] . 
" a part of the Griffin family?";       

　　輸出結果

Is Megan a part of the Griffin family?