functionformatNumber(val){if(val===undefined){return'nodata'}elseif(isNaN(+val)){returnval}elseif(!val){return0}letnewVal=val.toString()letarr=newVal.split('.')letinpart=arr[0].replace(/(\d)(?=(?:\d{3})+$)/g,'$1,')if(arr[1]){returninpart+'.'+arr[1]}else{returninpart}}console.log(formatNumber(12345678));结果：
