PHP之数组学习

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今天学习了数组,可以说是PHP的数据应用中较重要的一种方式。PHP的数组函数众多,下面是我学习的小结,借此记之,便于以后鉴之……

  一、数组定义:

  数组的定义使用 array()方式定义,可以定义空数组:
<div class="codetitle"><a style="CURSOR: pointer" data="39716" class="copybut" id="copybut39716" onclick="doCopy('code39716')"> 代码如下:
<div class="codebody" id="code39716">
<?PHP
$number = array(1,3,5,7,9);
//定义空数组
$result = array();
$color =array("red","blue","green");
//自定义键值
$language = (1=>"English",3=>"Chinese",5=>"Franch");
//定义二维数组
$two = array(
"color"=>array("red","blue"),//用逗号结尾
"week"=>array("Monday","Friday") //最后一句没有标点
);
?>

二、创建数组:

  创建数组包含的函数有compact()、
    1.compact()函数——将一个或多个变量(包含数组)转换为数组:
      array compact ( mixed $varname [,mixed $... ] )  
<div class="codetitle"><a style="CURSOR: pointer" data="31430" class="copybut" id="copybut31430" onclick="doCopy('code31430')"> 代码如下:
<div class="codebody" id="code31430">
<?PHP
$number = "1,9";
$string = "I'm PHPer";
$array = array("And","You?");
$newArray = compact("number","string","array");
print_r ($newArray);
?>

compact()函数用于将两个或多个变量转换为数组,当然也包含数组变量。其参数是变量的名称而非带有$全名。
      相反的函数是extract()作用顾名思义就是将数组转换为单个的字符串,键值作为其字符串名称,数组值作为字符串的值。
      运行结果:
<div class="codetitle"><a style="CURSOR: pointer" data="9404" class="copybut" id="copybut9404" onclick="doCopy('code9404')"> 代码如下:
<div class="codebody" id="code9404">
Array ( [number] => 1,9 [string] => I'm PHPer [array] => Array ( [0] => And [1] => You? ) )

2.array_combine()——将两个数组重组成一个数组,一个作键值一个做的值:
      array array_combine ( array $keys,array $values )
<div class="codetitle"><a style="CURSOR: pointer" data="48925" class="copybut" id="copybut48925" onclick="doCopy('code48925')"> 代码如下:
<div class="codebody" id="code48925">
<?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函数不多说了,谁看了都明白
      运行结果: Array ( [1] => I [3] => Am [5] => A [7] => PHP [9] => er )
    3.range()函数——创建指定范围的数组:
       不多说了,直接上实例——
<div class="codetitle"><a style="CURSOR: pointer" data="30362" class="copybut" id="copybut30362" onclick="doCopy('code30362')"> 代码如下:<div class="codebody" id="code30362">
<?PHP
$array1 = range(0,100,10);//0为起始值,100为结束值,10为步进值(默认步进值为1).
print_r($array1);
echo"
";
$array2 = range("A","Z");
print_r($array2);
echo "
";
$array3 = range("z","a");
print_r($array3);
?>

range()函数的默认步进值是1!
      运行结果:
<div class="codetitle"><a style="CURSOR: pointer" data="12608" class="copybut" id="copybut12608" onclick="doCopy('code12608')"> 代码如下:<div class="codebody" id="code12608">
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()函数——填充数组函数
<div class="codetitle"><a style="CURSOR: pointer" data="39312" class="copybut" id="copybut39312" onclick="doCopy('code39312')"> 代码如下:<div class="codebody" id="code39312">
<?PHP
$array = range(1,10);
$fillarray = range("a","d");
$arrayFilled = array_fill(0,$fillarray);//这里的$fillarray可以是字符串,如"test".
echo "
"; 
print_r ($arrayFilled);
echo "
";
$keys = array("string","2",9,"SDK","PK");
$array2 = array_fill_keys($keys,"testing");
echo "
"; 
print_r ($array2);
echo "
";
?>

运行结果:
<div class="codetitle"><a style="CURSOR: pointer" data="59202" class="copybut" id="copybut59202" onclick="doCopy('code59202')"> 代码如下:<div class="codebody" id="code59202">
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、数组的遍历:
    1.foreach遍历:
       foreach (array_expression as $value){}
       foreach (array_expression as $key => $value){}
      闲话少说,上实例:
<div class="codetitle"><a style="CURSOR: pointer" data="26090" class="copybut" id="copybut26090" onclick="doCopy('code26090')"> 代码如下:<div class="codebody" id="code26090">
<?PHP
$speed = array(50,120,180,240,380);
foreach($speed as $keys=>$values){
echo $keys."=>".$values."
";
}
?>

运行结果:
<div class="codetitle"><a style="CURSOR: pointer" data="25426" class="copybut" id="copybut25426" onclick="doCopy('code25426')"> 代码如下:<div class="codebody" id="code25426">
0=>50
1=>120
2=>180
3=>240
4=>380

2.while循环遍历:
      while循环遍历一般结合list函数,以下是实例
<div class="codetitle"><a style="CURSOR: pointer" data="859" class="copybut" id="copybut859" onclick="doCopy('code859')"> 代码如下:<div class="codebody" id="code859">
<?PHP
$staff = array(
array("姓名","性别","年龄"),
array("小张","男",24),
array("小王","女",25),
array("小李",23)
);
echo "";
while(list($keys,$value) = each($staff)){
list($name,$sex,$age) = $value;
echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>";
}
echo "</table>";
?>

运行结果:

姓名 性别 年龄
小张 24
小王 25
小李 23
3.for循环遍历:
代码如下:
PHP
$speed = range(0,220,20);
for($i =0;$iecho $speed[$i]."";
}
?>

运行结果:
代码如下:
0 20 40 60 80 100 120 140 160 180 200 220

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