关联数组

关联数组 ：每个位置占一对元素 k=>v 键=>值

<?php
        $age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
    echo "peter is" . $age['Ben'] . "years old.";
?>

遍历关联数组（使用foreach循环）：

<?php
    $age=array("Peter"=>"35","Ben"=>"37","Joe"=>"43");
    foreach($age as $k=>$v){
    
        echo "键key=". $k . ",值value=" . $v;
        echo "<br>";
    }
?>

<?php
         $x= array(12=>"Google",16=>"Runoob",18=>"Taobao");
         foreach($x as $key => $value){
                 echo "key 为 " . $key . ",对应的value为" . $value . "<br/>";
         }
?>