PHP之數組學習

今天學習了數組，可以說是PHP的資料應用中較重要的一種方式。PHP的數組函數眾多，下面是我學習的小結，藉此記之，便於以後鑒之……
　　一、數組定義：
　　數組的定義使用 array（）方式定義，可以定義空數組： 複製代碼 代碼如下:<?php
$number = array(1,3,5,7,9);
//定義空數組
$result = array();
$color =array("red","blue","green");
//自訂索引值
$language = (1=>"English",3=>"Chinese",5=>"Franch");
//定義二維數組
$two = array(
"color"=>array("red","blue"), //用逗號結尾
"week"=>array("Monday","Friday") //最後一句沒有標點
)；
?>

二、建立數組：
　　建立數組包含的函數有compact()、
　　　　1.compact()函數——將一個或多個變數（包含數組）轉換為數組：
　　　　　　array compact ( mixed $varname [, mixed $... ] )　　 複製代碼 代碼如下:<?PHP
$number = "1,3,5,7,9";
$string = "I'm PHPer";
$array = array("And","You?");
$newArray = compact("number","string","array");
print_r ($newArray);
?>

compact()函數用於將兩個或多個變數轉換為數組，當然也包含陣列變數。其參數是變數的名稱而非帶有$全名。
　　　　　　相反的函數是extract()作用顧名思義就是將數群組轉換為單個的字串，索引值作為其字串名稱，數組值作為字串的值。
　　　　　　運行結果: 複製代碼 代碼如下:Array ( [number] => 1,3,5,7,9 [string] => I'm PHPer [array] => Array ( [0] => And [1] => You? ) )

2.array_combine()——將兩個數組重組成一個數組,一個作索引值一個做的值：
　　　　　　array array_combine ( array $keys , array $values ) 複製代碼 代碼如下:<?PHP
$number = array("1","3","5","7","9");
$array = array("I","Am","A","PHP","er");
$newArray = array_combine($number,$array);
print_r ($newArray);
?>

array_combine函數不多說了，誰看了都明白
　　　　　　運行結果：

Array ( [1] => I [3] => Am [5] => A [7] => PHP [9] => er )
　　　　3.range()函數——建立指定範圍的數組：
　　　　　　　不多說了，直接上執行個體—— 複製代碼 代碼如下:<?PHP
$array1 = range(0,100,10);//0為起始值，100為結束值，10為步進值(預設步進值為1).
print_r($array1);
echo"<br />";
$array2 = range("A","Z");
print_r($array2);
echo "<br />";
$array3 = range("z","a");
print_r($array3);
?>

range()函數的預設步進值是1！
　　　　　　運行結果： 複製代碼 代碼如下:Array ( [0] => 0 [1] => 10 [2] => 20 [3] => 30 [4] => 40 [5] => 50 [6] => 60 [7] => 70 [8] => 80 [9] => 90 [10] => 100 )
Array ( [0] => A [1] => B [2] => C [3] => D [4] => E [5] => F [6] => G [7] => H [8] => I [9] => J [10] => K [11] => L [12] => M [13] => N [14] => O [15] => P [16] => Q [17] => R [18] => S [19] => T [20] => U [21] => V [22] => W [23] => X [24] => Y [25] => Z )
Array ( [0] => z [1] => y [2] => x [3] => w [4] => v [5] => u [6] => t [7] => s [8] => r [9] => q [10] => p [11] => o [12] => n [13] => m [14] => l [15] => k [16] => j [17] => i [18] => h [19] => g [20] => f [21] => e [22] => d [23] => c [24] => b [25] => a )

4.array_fill()函數——填充數組函數： 複製代碼 代碼如下:<?PHP
$array = range(1,10);
$fillarray = range("a","d");
$arrayFilled = array_fill(0,5,$fillarray);//這裡的$fillarray可以是字串，如"test".
echo "<pre>";
print_r ($arrayFilled);
echo "</pre>";
$keys = array("string","2",9,"SDK","PK");
$array2 = array_fill_keys($keys,"testing");
echo "<pre>";
print_r ($array2);
echo "</pre>";
?>

運行結果： 複製代碼 代碼如下:Array
(
[0] => Array
(
[0] => a
[1] => b
[2] => c
[3] => d
)
[1] => Array
(
[0] => a
[1] => b
[2] => c
[3] => d
)
[2] => Array
(
[0] => a
[1] => b
[2] => c
[3] => d
)
[3] => Array
(
[0] => a
[1] => b
[2] => c
[3] => d
)
[4] => Array
(
[0] => a
[1] => b
[2] => c
[3] => d
)
)
Array
(
[string] => testing
[2] => testing
[9] => testing
[SDK] => testing
[PK] => testing
)

二、數組的遍曆：
　　　　1.foreach遍曆：
　　　　　　　foreach (array_expression as $value){}
　　　　　　　foreach (array_expression as $key => $value){}
　　　　　　閑話少說，上執行個體： 複製代碼 代碼如下:<?PHP
$speed = array(50,120,180,240,380);
foreach($speed as $keys=>$values){
echo $keys."=>".$values."<br />";
}
?>

運行結果： 複製代碼 代碼如下:0=>50
1=>120
2=>180
3=>240
4=>380

2.while迴圈遍曆：
　　　　　　while迴圈遍曆一般結合list函數，以下是執行個體 複製代碼 代碼如下:<?PHP
$staff = array(
array("姓名","性別","年齡"),
array("小張","男",24),
array("小王","女",25),
array("小李","男",23)
);
echo "<table border=2>";
while(list($keys,$value) = each($staff)){
list($name,$sex,$age) = $value;
echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>";
}
echo "</table>";
?>

運行結果：

姓名	性別	年齡
小張	男	24
小王	女	25
小李	男	23

3.for迴圈遍曆： 複製代碼 代碼如下:<?PHP
$speed = range(0,220,20);
for($i =0;$i<count($speed);$i++) {
echo $speed[$i]." ";
}
?>

運行結果： 複製代碼 代碼如下:0 20 40 60 80 100 120 140 160 180 200 220