let result = Math
.random
()*(m+
1
-n)+n;
while
(result>m){
result = Math
.random
()*(m+
1
-n)+n;
return result;
function
fullOpen
(n,m){
let result = Math
.random
()*(m-n)+n;
while
(result == n){
result = Math
.random
()*(m-n)+n;
return result;
function
leftOpen
(n,m){
let result = Math
.random
()*(m-n+
1
)+n-
1
;
while
(result<n){
result = Math
.random
()*(m-n+
1
)+n-
1
;
return result;
4.生成随机整数
Math.round(num):四舍五入取整
Math.floor(num):将num向下取整,即返回num得整数部分。也可用parseInt()
//生成[0,n)范围内得随机整数
Math.floor(Math.random()*n)
//生成[nim,max]范围内得随机整数
Math.floor(Math.random()*(max-min+1))+min
//生成[1,n]范围内随机数
Math.floor(Math.random()*n)+1
5.随机字符串生成
//生成n位数字字符串
function randomNum(n){
let res = ''
for(let i=0
res += Math.floor(Math.random()*10)
return res
//生成n位数字字母混合得字符串
function generateMixed(n){
let 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']
let res = ''
for(let i=0
let id = Math.floor(Math.random()*36)
res += chars[id]
return res
复制代码