JS生成指定长度的随机数

 /**
  * 生成指定长度的UUID
  * @param len
  * @param radix
  * @returns uuid
  * eg: createUUID(8, 2) "01001010" createUUID(8, 10) "47473046" createUUID(8, 16) "098F4D35"
  */
调用
 var num = createUUID(6, 10);
 function createUUID(len, radix) {
     var chars = '0123456789'.split('');
     var uuid = [], i;
     radix = radix || chars.length;
     if(len){
       for (i = 0; i < len; i++){
           uuid[i] = chars[0 | Math.random()*radix];
       }
     }
     return '-'+uuid.join('');
 }