php文章tag标签的增删

<?php

session_start();

if($_POST){

    $_SESSION[‘old‘]=array(‘one‘,‘two‘,‘three‘,‘four‘,‘five‘);

    $_SESSION[‘old‘]=array();

    $_SESSION[‘old‘]=array(‘two‘,‘five‘);

    $new=(array) $_POST[‘big‘];

    foreach($new as $k=>$v){

        if(!in_array($v,$_SESSION[‘old‘])){

            $_SESSION[‘old‘][]=$v;

            echo ‘add ‘.$v;

            echo ‘<br />‘;

        }else{

            echo ‘mod ‘.$v;

            echo ‘<br />‘;

        }

    }

    foreach($_SESSION[‘old‘] as $k=>$v){

        if(!in_array($v,$new)){

            $id=array_keys($_SESSION[‘old‘],$v);

            unset($_SESSION[‘old‘][$id[0]]);

            echo ‘del ‘.$v;

            echo ‘<br />‘;

        }

    }

    echo "<pre>";

    print_r($_SESSION[‘old‘]);

}

?>

<form method="post">

<input type="checkbox" name="big[]" value="one" /> one<br />

<input type="checkbox" name="big[]" value="two" /> two<br />

<input type="checkbox" name="big[]" value="three" /> three<br />

<input type="checkbox" name="big[]" value="four" /> four<br />

<input type="checkbox" name="big[]" value="five" /> five<br />

<input type="submit" value="submit" name=‘abc‘>

</form>