switch function throwing off my code

Discussion in 'PHP' started by mnymkr, Apr 29, 2007.

  1. #1
    Hi , I want to lead in to this saying I am just learning this stuff. I thought I would code something I knew so I went with chemistry stuff.

    This code works great when I enter Ka values into a text box but when I try to use this switch for my radio buttons. I lose it.....any help would be great and any overall code improvements.....

    
    <html><head><title>Calculation Result</title></head>
    <body>
    <?php
    
    // moloarity calculation
    $neglog = $pH*-1;
    
    
    $hydronium = pow (10,$neglog);
    
    
    if($calc != null)
       {
            switch($calc)
            {
                 case "aceticacid" : $Ka=2; break;
                 case "ethanoicacid" : $Ka=100; break;
                 case "boricacid" : $Ka=1000; break;
                 
    
            }
    
    
    
       
       $result = (pow($hydronium,2)/$Ka) + $hydronium  ;
    $resulta = (pow($hydronium,2)/$Ka)   ;
            
            echo("Calculation result: $result");
       
    
    
    
    $volume = 0.400;
    $moles = $result* $volume;
    ?>
    
    <form method  = "post" action = "<?php echo $PHP_SELF;?>">
    PH: <input type="text" name="pH" size="10">
    Ka: 
    <input type="radio" name="calc" value= "aceticacid">Acetic Acid
    <input type="radio" name="calc" value="ethanoicacid">Ethanoic Acid
    <input type="radio" name="calc" value="boricacid">Boric Acid
    
    
    <input type="submit" value="Calculate">
    <input type="reset" value="Clear">
    </form>
    
    Hydronium concentration:
    <?php echo number_format($hydronium, "6", ".", ","); ?><br />
    Inital Molarity (no apprixmation): <?php echo number_format($result, "6", ".", ","); ?> <br />
    Inital Molarity (neglect x): <?php echo number_format($resulta, "6", ".", ","); ?> <br />
    moles required for <? echo $volume?> Liters of solution: <?php echo number_format($moles, "6", ".", ","); ?> <br />
    
    
    </body></html> 
    Code (markup):
     
    mnymkr, Apr 29, 2007 IP
  2. frankcow

    frankcow Well-Known Member

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    #2
    well, for one, you're not picking up the form $_POST value in the php and assigning it to a variable
     
    frankcow, Apr 29, 2007 IP
  3. mnymkr

    mnymkr Well-Known Member

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    #3
    im not sure if i see what you are talking about

    what do i need to change

    all i know is that i am copying a similar script that does something similar and if i take out the switch it works

    sorry very new to this...
     
    mnymkr, Apr 29, 2007 IP
  4. manilodisan

    manilodisan Peon

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    #4
    manilodisan, Apr 29, 2007 IP
  5. frankcow

    frankcow Well-Known Member

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    #5
    try adding
    
    $calc = $_POST['calc'];
    
    PHP:
    before
    
    if($calc != null)
    
    PHP:
     
    frankcow, Apr 30, 2007 IP