JS get random number function to customize minimum maximum value _javascript technique

Copy Code code as follows:

/**
* Lowervalue Minimum value
* Uppervalue Maximum Value
*/
function Selectfrom (Lowervalue, Uppervalue) {

Total Value Range
var choices = Uppervalue-lowervalue + 1;
Return Math.floor (Math.random () * choices + lowervalue);
}
var num = Selectfrom (2, 10);
alert (num);//A numeric value between 2 and 10 (including 2 and 10)

var colors = ["Red", "green", "blue", "yellow", "black", "Brown"];
var color = colors[selectfrom (0, colors.length-1)];
alert (color);//may be any one of the values contained in the array