generate an array of random numbers javascript

1//get random value from array
2var colors = ["red","blue","green","yellow"];
3var randColor = colors[Math.floor(Math.random() * colors.length)];
4

1//This example is to generate an array with 40 random elements, with random values from 0 to 39 
2
3for (var a=[],i=0;i<40;++i) a[i]=i;
4
5// http://stackoverflow.com/questions/962802#962890
6function shuffle(array) {
7  var tmp, current, top = array.length;
8  if(top) while(--top) {
9    current = Math.floor(Math.random() * (top + 1));
10    tmp = array[current];
11    array[current] = array[top];
12    array[top] = tmp;
13  }
14  return array;
15}
16
17a = shuffle(a);
18

1let numbersArray = [] , max = 100;
2
3for( var i=1; numbersArray.push(i++) < max;);  // numbers = [1,2,3 ... 100] 

1const randomElement = array[Math.floor(Math.random() * array.length)];
2