数组

数组操作

• 实例化
• 访问
• 遍历
• size

<?php

$ar = array('hello', 'world');
echo count($ar), " ", sizeof($ar), "\n";
for ($i = 0; $i < count($ar); $i++) {
    echo $ar[$i], "\n";
}
$ar2 = array("zw"=>28,"yh"=>26);
foreach ($ar2 as $key => $value) {  #not move pointer
    # code...
    echo $key,":",$value,"\n";
}
while (list($key,$value) = each($ar2)) { #move pointer
    # code...
    echo $key,":",$value,"\n";
}
reset($ar2); #need rest pointer
while ($element = each($ar2)) {
    # code...
    echo $element['key'],":",$element['value'],"\n";
}

if (array_key_exists('zw', $ar2)) {
    echo $ar2['zw'];
}

数组存在

php > $arr = array(1,2,3,4);
php > $in = in_array(3,$arr);
php > $not_in = in_array(5,$arr);
php > echo "in:".$in." not_in:".$not_in;
in:1 not_in: