用js函数加判断做出对象中负数四舍五入的效果

let x = prompt('请输入一个数字');
    function a ( t ){
      let q = Number(x);
      let b = parseInt(x);
      let c = 0;
      if( b > 0 ){
        if( q - b > 0.5){
          b = parseInt(b);
          b++;
          console.log(b);
        } else{
          b = parseInt(b);
          console.log(b);
        }
      } else if( b < 0 ) {
        if(q - b < -0.6){
          b = parseInt(b);
          b--;
          console.log(b);
        }else{
          b = parseInt(b);
          console.log(b);
        }
      }else{
        console.log(c);
      }
    }
    a( x );