www.webdeveloper.com
Results 1 to 5 of 5

Thread: Undefined variables in a random number function

  1. #1
    Join Date
    Jun 2006
    Location
    Doncaster
    Posts
    78

    Undefined variables in a random number function

    Evening all.

    I have a problem with some undefined variables ina function.

    Although there are comments in the code below, this is how it works.
    • When the user presses the button, a ranom number is generated
    • This numer is converted to a 1 or 0
    • this updates the running totals
    • the totals are displayed in the table

    The problem is that although it loads properly, I can't get the variable to update the table - I just getundefined.

    Here's the code:
    Code:
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Teabag calculator</title>
    <script language="javascript" type="text/javascript">
    i=0;
    var total=80;
    var single=0;
    var dbl=80;
    var i=0;
    function maketea()
    {
    document.getElementById('tries').innerHTML=i.value;
    var randomnumber=Math.floor(Math.random()*2);
    if (randomnumber==0)
    //low, ie single
    /*if a single bag is pulled, the doubles are unaffected, the singles fall by one 
    the total number falls by one, and the number of tries increases by one*/
    	{
    		single=single-1;
    		total=dbl+single;
    		i=i+1
    		document.getElementById('tries').innerHTML=i.value;
    		document.getElementById('doubles').innerHTML=dbl.value;
    		document.getElementById('singles').innerHTML=single.value;
    		document.getElementById('total').innerHTML=total.value;
    		document.getElementById('doubles').style.color="black";
    		document.getElementById('singles').style.color="red"
    	}
    else if(randomnumber==1)
    //high, ie double
    /*if a double is pulled, the doubles fall by one, the singles increase by one, 
    thetotal number stays the same and the tries goes up*/
    	{
    		dbl=dbl-1;
    		single=single+1;
    		total=dbl+single;
    		i=i+1;
    		document.getElementById('tries').innerHTML=i.value;
    		document.getElementById('doubles').innerHTML=dbl.value;
    		document.getElementById('singles').innerHTML=single.value;
    		document.getElementById('total').innerHTML=total.value;
    		document.getElementById('singles').style.color="black";
    		document.getElementById('doubles').style.color="red";
    	}
    };
    </script>
    <style type="text/css">
    <!--
    .style1 {font-size: large}
    -->
    </style>
    </head>
    
    <body>
    This page simulates the "Dad problem", as illustrated on <a href="http://answers.yahoo.com/question/index;_ylt=AvyknayS8m5RMuoYpmoj_lPsy6IX;_ylv=3?qid=20090106022211AAr5W7Q">Yahoo! Answers</a>.
    <hr />
    <INPUT TYPE="button" NAME="myButton" VALUE="Make the tea!" onClick="maketea()">
    <table width="125" border="0" cellspacing="0" cellpadding="0">
      <caption align="top">
      <span class="style1">In the box</span>
      </caption>
      
      <tr>
        <td>Number of cups made</td>
        <td>Doubles left</td>
        <td>Singles left</td>
        <td>Total in the box</td>
      </tr>
      <tr>
        <td id="tries">&nbsp;
        </td>
        <td id="doubles">80</td>
        <td id="singles">&nbsp;</td>
        <td id="total">80</td>
      </tr>
    </table>
    
    </body>
    </html>
    Can anyone help?

  2. #2
    Join Date
    Nov 2003
    Location
    Worthington, OH, USA
    Posts
    3,634
    Remove the .value on JS variables:
    HTML Code:
    <!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
    <html xmlns="http://www.w3.org/1999/xhtml">
    <head>
    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />
    <title>Teabag calculator</title>
    <script language="javascript" type="text/javascript">
    i=0;
    var total=80;
    var single=0;
    var dbl=80;
    var i=0;
    function maketea()
    {
    document.getElementById('tries').innerHTML=i.value;
    var randomnumber=Math.floor(Math.random()*2);
    if (randomnumber==0)
    //low, ie single
    /*if a single bag is pulled, the doubles are unaffected, the singles fall by one 
    the total number falls by one, and the number of tries increases by one*/
    	{
    		single=single-1;
    		total=dbl+single;
    		i=i+1
    		document.getElementById('tries').innerHTML=i;
    		document.getElementById('doubles').innerHTML=dbl;
    		document.getElementById('singles').innerHTML=single;
    		document.getElementById('total').innerHTML=total;
    		document.getElementById('doubles').style.color="black";
    		document.getElementById('singles').style.color="red"
    	}
    else if(randomnumber==1)
    //high, ie double
    /*if a double is pulled, the doubles fall by one, the singles increase by one, 
    thetotal number stays the same and the tries goes up*/
    	{
    		dbl=dbl-1;
    		single=single+1;
    		total=dbl+single;
    		i=i+1;
    		document.getElementById('tries').innerHTML=i;
    		document.getElementById('doubles').innerHTML=dbl;
    		document.getElementById('singles').innerHTML=single;
    		document.getElementById('total').innerHTML=total;
    		document.getElementById('singles').style.color="black";
    		document.getElementById('doubles').style.color="red";
    	}
    };
    </script>
    <style type="text/css">
    <!--
    .style1 {font-size: large}
    -->
    </style>
    </head>
    
    <body>
    This page simulates the "Dad problem", as illustrated on <a href="http://answers.yahoo.com/question/index;_ylt=AvyknayS8m5RMuoYpmoj_lPsy6IX;_ylv=3?qid=20090106022211AAr5W7Q">Yahoo! Answers</a>.
    <hr />
    <INPUT TYPE="button" NAME="myButton" VALUE="Make the tea!" onClick="maketea()">
    <table width="125" border="0" cellspacing="0" cellpadding="0">
      <caption align="top">
      <span class="style1">In the box</span>
      </caption>
      
      <tr>
        <td>Number of cups made</td>
        <td>Doubles left</td>
        <td>Singles left</td>
        <td>Total in the box</td>
      </tr>
      <tr>
        <td id="tries">&nbsp;
        </td>
        <td id="doubles">80</td>
        <td id="singles">&nbsp;</td>
        <td id="total">80</td>
      </tr>
    </table>
    
    </body>
    </html>
    54 68 65 42 65 61 72 4D 61 79

  3. #3
    Join Date
    Dec 2005
    Location
    FL
    Posts
    7,380
    It's just not fair that "TheBearMay" types faster than me!

  4. #4
    Join Date
    Nov 2003
    Location
    Worthington, OH, USA
    Posts
    3,634
    Lol
    54 68 65 42 65 61 72 4D 61 79

  5. #5
    Join Date
    Jun 2006
    Location
    Doncaster
    Posts
    78
    Thank-you for your quick and accurate reply!

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Tags for this Thread

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •  
HTML5 Development Center



Recent Articles