generate random NOT in array [duplicate]

If your problem is about how to implement the "try again" part, just call getRand recursively:

var restricted = [3, 4, 7];

function getRand() {
    var rand = Math.floor(Math.random() * 10);
    if ($.inArray(rand, restricted) === -1) {
        return rand;
    } else {
        return getRand();
    }
}

var rand = getRand();

Also, if all you're using jQuery for is the $.inArray method, I suggest using Array.prototype.indexOf instead (for incompatible browsers, a shim is available here).

You need a while loop that tests if rand is in your restricted array and, if so, re-generate a new random number:

var rand;
do { 
    rand = Math.floor(Math.random() * 10); // re-randomize
} while ($.inArray(rand, restricted) > -1);
return rand;

http://jsfiddle.net/mblase75/dAN8R/

Try this -

var restricted = [3, 4, 7];

function getRand () {
    var gotRand = false;
    var rand;
    while(!gotRand){  // loop until you got random number
       rand = Math.floor(Math.random() * 10);
       if ($.inArray(rand, restricted) === -1) {
          gotRand = true;
       }
    }
    return rand;
}

rand = getRand();