Going nuts with random number routine HELP!

Jim Davidson · Sep 21, 2003

Here's what I'm trying to do:

I have a string with 30 numbers in it. I want to generate a random
number between 0 an 30, go to that position in the string and get that
number. Here is the code you can run it and see it doesn't work. I'm
new at this (only about a week) but I thought this should work. Please
help.

It's probably something simple, but I don't see it.

<html>
<SCRIPT LANGUAGE="JavaScript1.3">

var nRandom = 0;
var nIndex = 0;
var string_of_Numbers = "849029184628003328749103294901"
/* *********************************** */
function buttonCheck()
/* *********************************** */
{
if (document.carForm.spinButton.value == "Start")
{
document.carForm.spinButton.value = "Stop";
}
else
{
document.carForm.spinButton.value ="Start";

nRandom = Math.round(Math.random() * 30 + 1);
nIndex = string_of_Numbers.indexOf(nRandom);

document.carForm.slot1.value = "Random number generated "+nRandom;
document.carForm.slot2.value = string_of_Numbers;
document.carForm.slot3.value = "Value located at that position
"+nIndex;

}
}

</SCRIPT>
<body>

<FORM NAME="carForm">
<p>
<INPUT TYPE=button VALUE=Start NAME="spinButton"
onClick=buttonCheck()>
<p>
<INPUT TYPE=text name="slot1" value="" size=50>
<p>
<INPUT TYPE=text name="slot2" value="" size=40>
<p>
<INPUT TYPE=text name="slot3" value="" size=50>
</form>
</body>
</html>

Lee · Sep 21, 2003

Jim Davidson said:

Here's what I'm trying to do:

I have a string with 30 numbers in it. I want to generate a random
number between 0 an 30, go to that position in the string and get that
number. Here is the code you can run it and see it doesn't work. I'm
new at this (only about a week) but I thought this should work. Please
help.

It's probably something simple, but I don't see it.

<html>
<SCRIPT LANGUAGE="JavaScript1.3">

Since you don't actually require version 1.3, that should be:

var nRandom = 0;
var nIndex = 0;
var string_of_Numbers = "849029184628003328749103294901"
/* *********************************** */
function buttonCheck()
/* *********************************** */
{
if (document.carForm.spinButton.value == "Start")
{
document.carForm.spinButton.value = "Stop";
}
else
{
document.carForm.spinButton.value ="Start";
nRandom = Math.round(Math.random() * 30 + 1);

That line will generate numbers ranging from 1 to 31, with
the first and last selected only half as often as any of
the others. Since the character positions are numbered from
0 to 29, you're going to have problems. To get values evenly
distributed over the character positions in your string, use:

nRandom = Math.floor(Math.random()*string_of_Numbers.length);

nIndex = string_of_Numbers.indexOf(nRandom);

The indexOf() method doesn't do what you think it does.
Change that line to:

nIndex = string_of_Numbers.charAt(nRandom);

Jim Davidson · Sep 21, 2003

Lee, what can I say...thank you, thank you, thank you! You don't know
how long I sat here scratching my head wondering why it wouldn't work

Thanks again

Dr John Stockton · Sep 21, 2003

JRS: In article <[email protected]>, seen

Lines: 81

Lee, what can I say...thank you, thank you, thank you! You don't know
how long I sat here scratching my head wondering why it wouldn't work

Thanks again

Reading the FAQ on the subject would have given you the answer.
It would also have guided you in the proper formatting of a Usenet News
reply,

I Need Help with making a function that draws in a canvas using location data.	1	Dec 17, 2021
Need help with code on website (noob)	2	Jul 18, 2022
Help with Visual Lightbox: Scripts	2	May 3, 2023
Please Help?	0	Jul 23, 2022
Help with code	0	Jun 12, 2022
I dont get this. Please help me!!	2	Jan 24, 2023
Help with my responsive home page	2	Dec 14, 2022
I need help making a zooming function	11	Dec 14, 2021

Going nuts with random number routine HELP!

Jim Davidson

Lee

Jim Davidson

Dr John Stockton

Ask a Question

Similar Threads

Members online

Forum statistics

Latest Threads