/**
* 格式化數字顯示方式
* 用法
* formatNumber(12345.999,'#,##0.00');
* formatNumber(12345.999,'#,##0.##');
* formatNumber(123,'000000');
* @param num
* @param pattern
*/
function formatNumber(num,pattern){
var strarr = num?num.toString().split('.'):['0'];
var fmtarr = pattern?pattern.split('.'):[''];
var retstr='';
// 整數部分
var str = strarr[0];
var fmt = fmtarr[0];
var i = str.length-1;
var comma = false;
for(var f=fmt.length-1;f>=0;f--){
switch(fmt.substr(f,1)){
case '#':
if(i>=0 ) retstr = str.substr(i--,1) + retstr;
break;
case '0':
if(i>=0) retstr = str.substr(i--,1) + retstr;
else retstr = '0' + retstr;
break;
case ',':
comma = true;
retstr=','+retstr;
break;
}
}
if(i>=0){
if(comma){
var l = str.length;
for(;i>=0;i--){
retstr = str.substr(i,1) + retstr;
if(i>0 && ((l-i)%3)==0) retstr = ',' + retstr;
}
}
else retstr = str.substr(0,i+1) + retstr;
}
retstr = retstr+'.';
// 處理小數部分
str=strarr.length>1?strarr[1]:'';
fmt=fmtarr.length>1?fmtarr[1]:'';
i=0;
for(var f=0;f<fmt.length;f++){
switch(fmt.substr(f,1)){
case '#':
if(i<str.length) retstr+=str.substr(i++,1);
break;
case '0':
if(i<str.length) retstr+= str.substr(i++,1);
else retstr+='0';
break;
}
}
return retstr.replace(/^,+/,'').replace(/\.$/,'');
}
alert(formatNumber(12345.999,'#,##0.00'));
</script>