Usage of generating random numbers in JS and related function _ javascript skills

This article mainly introduces how to generate random numbers in JS and provides related functions, if you are interested, you can refer to the following functions to introduce random numbers:
Var Rand = Math. random ();

• 1. Math. random (); the result is a random number (including 0, not 1) between 0 and 1)
• 2. Math. floor (num); the num parameter is a numerical value, and the function result is an integer part of num.
• 3. Math. round (num); the num parameter is a numerical value, and the function result is an integer rounded to num.

Math:Mathematical object that provides mathematical calculation of data.
Math. random ();Returns a random number between 0 and 1 (including 0, excluding 1.

Math. ceil (n );Returns the smallest integer greater than or equal to n.
UseMath. ceil (Math. random () * 10 );Obtain a random integer ranging from 1 to 10. the probability of getting 0 is very small.

Math. round (n );Returns the integer value after n rounding.
UseMath. round (Math. random ());Returns a random integer ranging from 0 to 1.
UseMath. round (Math. random () * 10 );You can obtain a random integer ranging from 0 to 10 in a balanced manner. the probability of obtaining a minimum value of 0 and a maximum value of 10 is less than half.

Math. floor (n );Returns the largest integer less than or equal to n.
UseMath. floor (Math. random () * 10 );You can obtain random integers ranging from 0 to 9 in a balanced manner.
The random lottery can also be expanded. for example, you can set the probability of a lottery and use it with the database.

// Demand for the probability of winning, 100% winning, three prizes, but the probability of getting a book is 20% function draw () {var d_s = GetRandom (100 ); if (d_s> = 1 & d_s <= 40) {alert ('Congratulations, you have drawn XXX! ');} Else if (d_s> = 41 & d_s <= 80) {alert ('Congratulations, you have drawn XXX! ');} Else {alert (' Congratulations, you have obtained the book! ');}}

Function code for generating random numbers in the corresponding js:

《script》  2function GetRandomNum(Min,Max){    var Range = Max - Min;    var Rand = Math.random();    return(Min + Math.round(Rand * Range));  }   8var num = GetRandomNum(1,10);   9alert(num);  《script》var chars = ['0','1','2','3','4','5','6','7','8','9','A','B','C','D','E','F','G','H','I','J','K','L','M','N','O','P','Q','R','S','T','U','V','W','X','Y','Z'];function generateMixed(n) {   var res = "";   for(var i = 0; i < n ; i ++) {     var id = Math.ceil(Math.random()*35);     res += chars[id];   }   return res;}

The above is the detailed content of this article, hoping to help you learn.