generate non repeting random numbers

[eihabisaac]

hey
i wrote this function to generete random numbers. it works but i don't wont these number to be repeated so any idea.
i'm using images to show the numbers.

<script type="text/javascript">

function shuffle()
{
var imgval;
 
document.write("<table border='1'>")
var k=1;
 
for (var i=1;i<=3;i++)
{
    document.write("<tr>");
        for(var j=0;j<3;j++)
        {
        imgval = Math.floor( 1 + Math.random() * 9);
 
        document.write("<td><img src='Image"+(imgval)+".bmp' </td>");
 
        }
        k+=3;
    document.write("</tr>");
}
document.write("</table>");
 
 
}

</script>

[acoder]

Not quite, that'd give you 0 - 9.

However, your solution (in post #8) for this particular case (1-9) works fine. It'd have to change if you wanted anything greater than 9.

[mrhoo]

I would get the randomized array at one go,
and then build the html string so that
only one write needs to be called.

function shuffleImages(){
    var A= [], i= 1;
    while(i<10) A.push(i++);
    A.sort(function(){return Math.random()-.5})
 
    var str= '<table>\n<tbody>\n';
    var prefix= '<td><img src="Image';
    var suffix= '.bmp"></td>';
    while(A.length){
        str+= '<tr>'+prefix+ 
        A.splice(0,3).join(suffix+prefix)+suffix+'</tr>\n';
    }
    return(str+'</tbody>\n</table>');
    //document.write(str+'</tbody>\n</table>');
}

shuffleImages()

/* returned value:
<table>
<tbody>
<tr><td><img src="Image4.bmp "></td>
<td><img src="Image8.bmp "></td>
<td><img src="Image1.bmp "></td></tr>
<tr><td><img src="Image5.bmp "></td>
<td><img src="Image2.bmp "></td>
<td><img src="Image9.bmp "></td></tr>
<tr><td><img src="Image6.bmp "></td>
<td><img src="Image7.bmp "></td>
<td><img src="Image3.bmp "></td></tr>
</tbody>
</table>
*/