如何来回遍历数组

Question

I have an array something like this

$steps = explode("[;;]",$str);

So the $steps holds value that I have to use to show a step/step procedure in PHP .

The array looks like this

$steps = array('corredores' , 'something' , 'something'...and so one );

I am trying to display forms according to the value saved in the array . I am able to go forward using some validation but I have trouble in moving to the previous name in the array , for the first step I am doing something like this

$steps = explode("[;;]",$_POST['str']);
$x = explode("=",$steps[0]);
$pais1 = $_POST['pais'];
$cnt=0;
    switch($steps[0]){
        case 'categorias' :
        include  'obj/categorias.php';
                    //$step='categorias';
                    break;
        case 'corredores':
        include 'obj/corredores.php';
                    //$step='corredores';
                    break;
        case 'monedas':
        include 'obj/monedas.php';
                    //$step='monedas';
                    break;
        case 'location':
        include 'obj/location.php';
                    //$step='location';
                    break;
        default:
        break;  
    }

//Here I am trying to match the next value from the array that I will save in this post value on every step

    if(isset($_POST['next1']) &&$_POST['method'] != "fase1")
{
$cnt =$_POST['cnt'];
$cnt++;
$array_var = unserialize(base64_decode($_POST["next1"]));
$steps = $array_var;
$pais1 = $_POST['pais'];

    $x = explode("=",$array_var[$cnt]);
include  'obj/'.trim($x[0]).'.php';
                //$step='categorias';   
}

So when I click on the next button of each file it goes to the next file in the array , But Now I need to add similar functionality to the previous button so that it goes back

The HTML content of every files has following structure

   <form method="post" action="./index.php" name="form_name">
    <table><tr><th>Some Name</td></tr>
    <tr><td><input type="submit" value="previous"></td><td><input type="submit" value="next"></td></tr></table>
<input type="hidden" name="next1" value="<?php print base64_encode(serialize($steps))  ?>">
<input type="hidden" name="pais" value="<?php echo $pais1?>"/>
<input type="hidden" id="cnt" name="cnt" value="<?php echo $cnt ?>" />
    </form>

Can any one give me some suggestion

Thanks in Advance

Answer 1

If I am not reading your code wrong, you already have an array of all the objects stored in next1 and cnt as your currently counter. Essentially, what you need to do is to detect whether the user has pressed the Next or Previous button

<input type="sumbit" name="next" value="Next">
<input type="submit" name="previous" value="Previous">

A form can have more than 1 submit button. Just be sure to name them differently. Then when you process your form:

if (isset($_POST['next'])) {
  // go on to the next object
  $cnt = $_POST['cnt'] + 1;

} else if (isset($_POST['previous']) {
  $cnt = $_POST['cnt'] - 1;
}

// retrieve object from array and include its file

It is important that you don't increment your cnt like above -- and only increment or decrement it before you press the buttons.

In short, change the value of cnt depending if the user presses Next or Previous.