PHP訪問陣列中元素的方法

//先定義兩個陣列

$breads = array("baguette", "naan", "roti", "pita");

$computer = array("processor" => "muncheron 6000",

"memory" => 2048, "hdd1" => 80000,

"graphics" => "nti monster gfi q9000");

// example 1

// 用整數鍵2來訪問陣列元素，沒有問題。

//echo "i like to eat $breads[2] every day!

// example 2

// 用變數鍵訪問陣列元素，也沒有問題。

//$feature = "memory"; 

echo "my pc has $computer[$feature]mb of memory

// example 3, 4

// 用字串型別的鍵訪問陣列元素，兩個都提示錯誤

//echo "my pc has a $computer['processor'] processor

\n";

echo "my pc has a $computer["processor"] processor

\n";

// example 5, 6

// 將example 3, 4改為如下就ok了，但不提倡example 6，看了example 7,8就明白了

//echo "my pc has a processor

\n";

echo "my pc has a $computer[processor] processor

\n"; 

//// example 7,8

// 不帶引號指定鍵名是外邊應該有雙引號，example 7提示錯誤,example 8正常

// echo $computer[processor]; 

//example 9

//引用不存在的索引，也會出問題

//echo "my pc has a sound card

\n";

////example 10

//正確使用常量的方法

//define('fffa',"memory");

echo "my pc has mb of memory

\n";

$computer = array("memory" => 2048, 2=>1024);

define('memory',2);

echo "my pc has $computer[memory]mb of memory

\n";  //my pc has 2048mb of memory

echo "my pc has mb of memory

\n"  //my pc has 1024mb of memory