JS如何获取指定范围内的随机数含小数

 randomNum(maxNum, minNum, decimalNum) {
            // 获取指定范围内的随机数, decimalNum指小数保留多少位
            var max = 0,
                min = 0;
            minNum <= maxNum ? (min = minNum, max = maxNum) : (min = maxNum, max = minNum);
            switch (arguments.length) {
                case 1:
                    return Math.floor(Math.random() * (max + 1));
                    break;
                case 2:
                    return Math.floor(Math.random() * (max - min + 1) + min);
                    break;
                case 3:
                    return (Math.random() * (max - min) + min).toFixed(decimalNum);
                    break;
                default:
                    return Math.random();
                    break;
            }
        },

<script>
    console.log(Math.random());
</script>

function getRandom(min,max) {
    min = Math.ceil(min);        // 确保当输入为小数时，仍能取范围内的整数
    max = Math.floor(max); 
    return Math.floor(Math.random() * (max - min)) + min;
 }
 console.log(getRandom(1.5,5.5));

function getRandom(min,max) {
    min = Math.ceil(min);        // 确保当输入为小数时，仍能取范围内的整数
    max = Math.floor(max);
    return Math.floor(Math.random() * (max - min + 1)) + min;
}
console.log(getRandom(10.5,20.5));

<script>
   function getRandom(min,max) {
        min = Math.ceil(min);        
        max = Math.floor(max); 
        return Math.floor(Math.random() * (max - min)) + min;
   }
 
   var flag = getRandom(1,10);
   console.log(flag);
 
   while(1){
       var number = prompt("请输入您所猜的数值范围（1-10）");
       if(number < flag) {
           alert("猜小了，请重新输入！");
       } else if(number > flag) {
           alert("猜大了，请重新输入！");
       }else {
           alert("猜对了，该随机数为：" + flag); 
           break;
       }
   }
</script>