javaScript产生随机数的用法小结: 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