How to Loop randomly in javascript?

Question

$rowCount = 40 ; 
for (var $j = 0; $j < $rowCount -1; $j++) {
    var currentNum = #something
}

I need to have a mechanism, where I can loop in a way that I will be applying the values to the currentNum in a random way.

Eg: At the end of the loop, the currentNum should have the value (0....39). But it shouldn't be applied starting from 0,1,2,3,4,5,6,7,8,.....39.

It should be applied in a random way like 39, 4, 5,17, 28 , 16 .... and it should cover all the numbers from 0-40. I figured this can be achieved using a HashMap in java, but how to implement in javascript?

http://stackoverflow.com/questions/2450954/how-to-randomize-shuffle-a-javascript-array Like [this](https://jsfiddle.net/rayon_1990/sp6uvjek/) — Rayon, Mar 21 '16 at 10:29
HashMap is not guaranteed to preserve the order. But it might do so. — Simon, Mar 21 '16 at 10:35

score 0 · Answer 1 · answered Mar 21 '16 at 10:48

0

var numbers = Array(rowCount);
for(var i = 0; i < rowCount; i++) numbers[i] = i;

shuffle(numbers); // randomly shuffle array elements

for (var $j = 0; $j < $rowCount -1; $j++) {
    var currentNum = numbers[i];
}

answered Mar 21 '16 at 10:48

Simon

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34

score 0 · Answer 2 · answered Mar 21 '16 at 10:50

You can try something like this:

var _data = [];
for (var i = 0; i < 40; i++) {
  _data.push(i);
}

var result = [];

_data.slice().forEach(function(){
 result.push(getRandomValue(_data))
});

function getRandomValue(arr,i) {
  var r = Math.floor(Math.random() * arr.length);
  var result = arr[r];
  arr.splice(r, 1);
  return result;
}

document.write("<pre>" + JSON.stringify(result,0,4) + "</pre>");

How to Loop randomly in javascript?

2 Answers2