PHP之数组学习_php技巧

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：

 <BR><?php <BR>$number = array(1,3,5,7,9); <BR>//定义空数组 <BR>$result = array(); <BR>$color =array("red","blue","green"); <BR>//自定义键值 <BR>$language = (1=>"English",3=>"Chinese",5=>"Franch"); <BR>//定义二维数组 <BR>$two = array( <BR>"color"=>array("red","blue"), //用逗号结尾 <BR>"week"=>array("Monday","Friday") //最后一句没有标点 <BR>)； <BR>?> <BR>

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 $… ] )　　

 <BR><?PHP <BR>$number = "1,3,5,7,9"; <BR>$string = "I'm PHPer"; <BR>$array = array("And","You?"); <BR>$newArray = compact("number","string","array"); <BR>print_r ($newArray<b style="color:transparent">来&源gao@dai!ma.com搞$代^码%网</b><img>搞gaodaima代码</img>); <BR>?> <BR>

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:

 <BR>Array ( [number] => 1,3,5,7,9 [string] => I'm PHPer [array] => Array ( [0] => And [1] => You? ) ) <BR>

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 )

 <BR><?PHP <BR>$number = array("1","3","5","7","9"); <BR>$array = array("I","Am","A","PHP","er"); <BR>$newArray = array_combine($number,$array); <BR>print_r ($newArray); <BR>?> <BR>

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——

 <BR><?PHP <BR>$array1 = range(0,100,10);//0为起始值，100为结束值，10为步进值(默认步进值为1). <BR>print_r($array1); <BR>echo"<br />"; <BR>$array2 = range("A","Z"); <BR>print_r($array2); <BR>echo "<br />"; <BR>$array3 = range("z","a"); <BR>print_r($array3); <BR>?> <BR>

range()函数的默认步进值是1！
　　　　　　运行结果：

 <BR>Array ( [0] => 0 [1] => 10 [2] => 20 [3] => 30 [4] => 40 [5] => 50 [6] => 60 [7] => 70 [8] => 80 [9] => 90 [10] => 100 ) <BR>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 ) <BR>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 ) <BR>

4.array_fill()函数——填充数组函数：

 <BR><?PHP <BR>$array = range(1,10); <BR>$fillarray = range("a","d"); <BR>$arrayFilled = array_fill(0,5,$fillarray);//这里的$fillarray可以是字符串，如"test". <BR>echo "<pre class="prettyprint linenums">"; <BR>print_r ($arrayFilled); <BR>echo "

“;
$keys = array(“string”,”2″,9,”SDK”,”PK”);
$array2 = array_fill_keys($keys,”testing”);
echo “

"; <BR>print_r ($array2); <BR>echo "

“;
?>

运行结果：

 <BR>Array <BR>( <BR>[0] => Array <BR>( <BR>[0] => a <BR>[1] => b <BR>[2] => c <BR>[3] => d <BR>) <BR>[1] => Array <BR>( <BR>[0] => a <BR>[1] => b <BR>[2] => c <BR>[3] => d <BR>) <BR>[2] => Array <BR>( <BR>[0] => a <BR>[1] => b <BR>[2] => c <BR>[3] => d <BR>) <BR>[3] => Array <BR>( <BR>[0] => a <BR>[1] => b <BR>[2] => c <BR>[3] => d <BR>) <BR>[4] => Array <BR>( <BR>[0] => a <BR>[1] => b <BR>[2] => c <BR>[3] => d <BR>) <BR>) <BR>Array <BR>( <BR>[string] => testing <BR>[2] => testing <BR>[9] => testing <BR>[SDK] => testing <BR>[PK] => testing <BR>) <BR>

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：

 <BR><?PHP <BR>$speed = array(50,120,180,240,380); <BR>foreach($speed as $keys=>$values){ <BR>echo $keys."=>".$values."<br />"; <BR>} <BR>?> <BR>

运行结果：

 <BR>0=>50 <BR>1=>120 <BR>2=>180 <BR>3=>240 <BR>4=>380 <BR>

2.while循环遍历：
　　　　　　while循环遍历一般结合list函数，以下是实例

 <BR><?PHP <BR>$staff = array( <BR>array("姓名","性别","年龄"), <BR>array("小张","男",24), <BR>array("小王","女",25), <BR>array("小李","男",23) <BR>); <BR>echo "<table border="2">"; <BR>while(list($keys,$value) = each($staff)){ <BR>list($name,$sex,$age) = $value; <BR>echo "<tr><td>$name</td><td>$sex</td><td>$age</td></tr>"; <BR>} <BR>echo "</table>"; <BR>?> <BR>

运行结果：

 <BR><?PHP <BR>$speed = range(0,220,20); <BR>for($i =0;$i<count($speed);$i++) { <BR>echo $speed[$i]." "; <BR>} <BR>?> <BR>

运行结果：

 <BR>0 20 40 60 80 100 120 140 160 180 200 220 <BR>

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