js 生成任意长度的随机数

function randomWord(length=32){//默认32位
			//由以下元素组成
            let arr=['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 num='';
            for(let i=0;i<length;i++){
                num+=arr[parseInt(Math.random()*arr.length)];
            }
            return num;
        }
        let key=randomWord(12);//生成12位随机数
        console.log(key);