1. 十进制转二进制

     let arr = 12;
     console.log(arr.toString(2));//1100

2.二进制转换十进制

    let tmp = 1100;
    let num = parseInt(tmp,2);

字符串补充长度

'1100'.padStart(32,'0');//00000000000000000000000000001100
'1100'.padEnd(32,'*');// 1100****************************