js求整，取個位 ，十位，百位，千位，萬位，十萬位，百萬位，千萬位

var max =19.00;
    var ge = max - ((Math.floor(max / 10)) * 10);
    var shi = (max - ((Math.floor(max / 100)) * 100) - ge) / 10;
    var qian= (max-((Math.floor(max / 10000)) * 10000) -(bai*100)- (shi * 10) - ge) / 1000;
    var wan= (max-((Math.floor(max / 100000)) * 100000) -(qian*1000)-(bai*100)- (shi * 10) - ge) / 10000;
    var shiwan=(max-((Math.floor(max / 1000000)) * 1000000) -(wan*10000)-(qian*1000)-(bai*100)- (shi * 10) - ge) / 100000;
    var baiwan=(max-((Math.floor(max / 10000000)) * 10000000) -(shiwan*100000)-(wan*10000)-(qian*1000)-(bai*100)- (shi * 10) - ge) / 1000000;
    var qianwan=(max-((Math.floor(max / 100000000)) * 100000000) -(baiwan*1000000)-(shiwan*100000)-(wan*10000)-(qian*1000)-(bai*100)- (shi * 10) - ge) / 10000000;
    
     var maxval;
   if (qianwan != 0) {
        if ((baiwan + 1) > 9) {
            maxval = parseInt((qianwan+1)  + '0000000');
        }
        else {
            maxval = parseInt(qianwan + '' + (baiwan + 1) + '000000');
        }
        
    }
    else if (baiwan != 0) {
        if ((shiwan + 1)>9)
        {
            maxval = parseInt((baiwan+1) + '000000');
        }
        else{
            maxval = parseInt(baiwan + '' + (shiwan + 1) + '00000');
        }
      
    }
    else if (shiwan != 0) {
        if ((wan + 1) > 9) {
            maxval = parseInt((shiwan + 1)+ '00000');
        }
        else {
            maxval = parseInt(shiwan + '' + (wan + 1) + '0000');
        }
    }
    else if (wan != 0) {
        if ((qian + 1) > 9) {
            maxval = parseInt((wan + 1)  + '0000');
        }
        else {
            maxval = parseInt(wan + '' + (qian + 1) + '000');
        }
    }
    else if (qian != 0) {
        if ((bai + 1) > 9) {
            maxval = parseInt((qian + 1) +'000');
        }
        else {
            maxval = parseInt(qian + '' + (bai + 1) + '00');
        }
       
    }
    else if (bai != 0) {
        if ((shi + 1) > 9) {
            maxval = parseInt((bai + 1) + '00');
        }
        else {
            maxval = parseInt(bai + '' + (shi + 1) + '0');
        }
    }
    //else if (shi != 0) {
    //    if ((ge + 1) > 9) {
    //        maxval = parseInt((shi + 1) + '0');
    //    }
    //    else {
    //        maxval = parseInt(shi + (ge + 1) + '0');
    //    }
    //}
    else{
        maxval = parseInt((shi + 1) + '0');
    }
    alert(maxval);