How to get an input from a user and bubble sort that input?

Question

I'm new to php, I'm trying to create a program that asks the user for number of elements, then input these elements, then bubbles sort them.

<?php
  function bubbleSort(array $arr)
{
    $n = sizeof($arr);   
    for ($i = 1; $i < $n; $i++) {
        $flag = false;
        for ($j = $n - 1; $j >= $i; $j--) {
            if($arr[$j-1] > $arr[$j]) {
                $tmp = $arr[$j - 1];
                $arr[$j - 1] = $arr[$j];
                $arr[$j] = $tmp;
                $flag = true;
            }
        }
        if (!$flag) {
            break;
        }
    }

    return $arr;
}

// Example:
$arr = array(255,1,'a',3,45,5);
$result = bubbleSort($arr);
print_r($result); 
?>

My code works fine if I store the array, What I'm trying to do is to ask the user for the input instead of storing it in the code. Can anyone help me out of how to ask the user of how many elements needed and then input these elements?

score 0 · Answer 1 · edited May 23 '17 at 10:32

If you want to read user input from the command line, you need to read from STDIN (standard input, when the user is running your script in the CLI). This might be a duplicate of this question: PHP standard input?

If, however, you want to display a web page and have users insert data into your script from their browser, you need to create a form and then access the form information via $_POST.

score 0 · Accepted Answer · answered Apr 24 '14 at 17:22

Try this html code.

<!doctype html>
<html>
    <head>
        <meta charset="utf-8">
        <title>Submit a Ticket</title>
        <style type="text/css" media="screen">
            .hidden {
                display: none;
            }
        </style>
    </head>

    <body>
        <form name="form1" id="form1" method="post" action="<?php $_SERVER['PHP_SELF']?>">
            <h5>Bubble Sort</h5>
            <h6>Fill the values</h6>
            <label>Value 1<input type="text" name="bubble_values[]" id="bubble_values1" size="10" maxlength="10"></label><br>
            <label>Value 2<input type="text" name="bubble_values[]" id="bubble_values2" size="10" maxlength="10"></label><br>
            <label>Value 3<input type="text" name="bubble_values[]" id="bubble_values3" size="10" maxlength="10"></label><br>
            <label>Value 4<input type="text" name="bubble_values[]" id="bubble_values4" size="10" maxlength="10"></label><br>
            <label>Value 5<input type="text" name="bubble_values[]" id="bubble_values5" size="10" maxlength="10"></label><br>
            <input type="submit" value="Sort it!" id="bt-submit">
        </form>

        <h3>Result</h3>
        <?php
        function bubbleSort(array $arr)
        {
            $n = sizeof($arr);   
            for ($i = 1; $i < $n; $i++) {
                $flag = false;
                for ($j = $n - 1; $j >= $i; $j--) {
                    if($arr[$j-1] > $arr[$j]) {
                        $tmp = $arr[$j - 1];
                        $arr[$j - 1] = $arr[$j];
                        $arr[$j] = $tmp;
                        $flag = true;
                    }
                }
                if (!$flag) {
                    break;
                }
            }

            return $arr;
        }

        // Example:
        if (isset($_POST['bubble_values']) && !empty($_POST['bubble_values'])) {
            echo '<pre>';
            echo 'Before sort: ';
            print_r($_POST['bubble_values']);
            echo '<br>--------------------<br>';
            echo 'After sort:' ;
            print_r(bubbleSort($_POST['bubble_values'])); 
            echo '</pre>';
        }
        ?>
    </body>
</html>

score 0 · Answer 3 · answered Apr 24 '14 at 17:28

This is probably a 'homework' question, but I'll take a stab.

I'd provide the user a . Indicate in the page's text that each value should be separated by a line break. Then, in the $_POST variables, use split('\r\n', $_POST['myvar']) to get an array where each line is an element in the array.

How to get an input from a user and bubble sort that input?

3 Answers3