Fisher Yates随机播放1个显示的数字

Question

I am using the Fisher Yates Shuffle and gone through the little tutorial, I can see that you can randomize an order such as 4,1,3,2,6,7,5 etc... but I want to find out how to have only 1 number shown. There could be a submit button and when I press submit a random number between 1 to 7 is shown. That number is then put aside so when I hit submit again there will be a 100% chance I wont see that number again. So basically I can press submit 7 times and the 8th time nothing will happen. this was the Javascript i was using:

    <script>
Array.prototype.shuffle = function(){
  var i = this.length, j, temp;
while(--i > 0) {
    j = Math.floor(Math.random() * (i+1));
    temp = this[j];
    this[j] = this[i];
    this[i] = temp;
    }
    return this;
}
var arr = ['A','B','C','D','E','F','G','H'];
var result = arr.shuffle();

document.write(result);
</script>

I have googled this with no success, Many thanks.

Answer 1

Here is my implementation of it that I have used.

function fisherYates ( myArray,stop_count ) {
  var i = myArray.length;
  if ( i == 0 ) return false;
  var c = 0;
  while ( --i ) {
     var j = Math.floor( Math.random() * ( i + 1 ) );
     var tempi = myArray[i];
     var tempj = myArray[j];
     myArray[i] = tempj;
     myArray[j] = tempi;
     c++;
     if(c == stop_count)return;
   }
}

You can call this with :

fisherYates(arr,Math.min(nr_items, selectionSize));

---

Note that

 var tempi = myArray[i];
 var tempj = myArray[j];
 myArray[i] = tempj;
 myArray[j] = tempi;

is a dumber version of:

 var temp = myArray[i];
 myArray[i] = myArray[j];
 myArray[j] = temp;

Answer 2

You could print a particular position within the array, because it's randomised each time- isn't it? So, you could create a variable with that position, and then print the variable. Eg

var finalResult = arr[2]; //you can have any position you want
document.write(finalResult);

That should work for you.