Use a single textbox to keep adding values to array after post

Question

So I'm currently working on a little project that allows a user to input a number into a textbox, after clicking a button that says "add" it should store that value into an array and then allow the user to input another value into that array. There is also a button on the page when the user is finished and wants to sum the values called "Submit". The problem I'm running into is everytime the form posts back, it recreates a new blank array. Any tips?

See the code below:

<html>
<head>
</head>
<body>
<h2>Please Select your title and name:</h2>
<form action='<?php echo $_SERVER["PHP_SELF"]; ?>' method='post'>
    <p>
        <label for="strFirstname">Type number to add: </label>
        <input type='text' name='strNumber' id='strNumber'/>
    </p>
    <p>
        <input type='submit' name='submit' value='Add' />
    </p>
    <p>
        <input type='submit' name='calculate' value='Compute' />
    </p>
    <?php

    $array = array();

    if (isset($_POST['submit']))
    $num = $_POST['strNumber'];
    $array[] = $num;
        foreach($array as $num)
        echo $num . ' + ';

    if(isset($_POST['calculate']))
        foreach($array as $num)
            echo $num . ' + ';
    ?>
</form>
</body>
</html>

Note that arrays only "live" during the page execution. You will have to use sessions, or cookies, or hidden inputs, or whatever else. However, for me it sounds like a client-side solution (JS, for example) will be the most suitable. — Yeldar Kurmangaliyev
– Yeldar Kurmangaliyev, Commented Nov 10, 2015 at 4:54
I was thinking about using a session, but am unfamiliar with the process @YeldarKurmangaliyev — Oystermaker
– Oystermaker, Commented Nov 10, 2015 at 4:58

Velko Georgiev · Accepted Answer · 2015-11-10 05:21:48Z

1

<?php
session_start();
?>
<html>
    <head>
    </head>
    <body>
        <h2>Please Select your title and name:</h2>
        <form action='' method='post'>
            <p>
                <label for="strFirstname">Type number to add: </label>
                <input type='text' name='strNumber' id='strNumber'/>
            </p>
            <p>
                <input type='submit' name='submit' value='Add' />
            </p>
            <p>
                <input type='submit' name='calculate' value='Compute' />
                <input type='submit' name='clear' value='clear' />
            </p>
            <?php
                if (isset($_POST['submit'])) {
                    if(!array_key_exists("numbers", $_SESSION)) {
                        $_SESSION["numbers"] = array();
                    }

                    array_push($_SESSION["numbers"], $_POST["strNumber"]);
                }

                if(isset($_POST['clear'])) {
                    $_SESSION["numbers"] = array();
                }

                if(array_key_exists("numbers", $_SESSION)) {
                    echo implode("+", $_SESSION["numbers"]);
                }

                if(isset($_POST['calculate'])) {
                    if(array_key_exists("numbers", $_SESSION)) {
                        $expression = implode("+", $_SESSION["numbers"]);
                        eval( '$result = (' . $expression . ');' );
                        echo "=" . $result;
                    }
                }
            ?>
        </form>
    </body>
</html>

Start a session
When the action is "submit"
- Check if the session which will store the numbers is initialized
- If it's not initialize it as an array
- Finally push the number into the array
Check if there is a session initialized if there is print all the numbers ( you can use implode to do that)
if the action is calculate .. just make the calculation ( check eval function )

edited Nov 10, 2015 at 5:21

answered Nov 10, 2015 at 5:08

Velko Georgiev

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3 Comments

Oystermaker Over a year ago

This is working, now I just need to echo all the numbers such as if I input 5, 6, 8. I need to echo 5 + 6 + 8 = 19

Velko Georgiev Over a year ago

Sorry SO is buging me this is not the entire source 1 min

Oystermaker Over a year ago

What did you change, I don't see the difference?

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