The application of random in JS

1. Generate a random number

var r = math.random (); Console.info (r);

The result is a random number of 0-1 ( returns the pseudo-random number between 0 and 1, possibly 0, but always less than 1,[0,1))

2. Generate a random integer of a specified range

/* *start < end* */ function Randomnum (start,end) {    return Math.floor (Math.random () * (End-start) +start;} Console.log (Randomnum (10,90));

First of all, there is no guarantee that this is absolutely right, I think it's right.

For example (10,90) because the value generated by Math.random () is at 0-1, so the Math.random () * (End-start) range is in [0,80], and Math.floor () guarantees that the value taken is an integer. Finally add 10, it becomes the [10,90];

3. Scrambled array sorting

function Resortarr () {        var length = arr.length;      for (var i=0;i<length;i++) {        var rnum = Math.floor (Math.random () * (length-1));         var temp = arr[i];         = Arr[rnum];         = temp;    }     return arr;} var arr = [1,2,3,4,5,6];console.log (Resortarr (arr));

Results

The application of random in JS