几个javascript的小工具

//判断是否是日期型数据
function isDate(dateVal)
{
var a1=dateVal.replace(/-/g,"/");
var dd=new Date(a1);
var ss=dd.getYear();
if(isNaN(ss))
return false;
else
return true;
}

//保留小数点精度，发现有些版本比较低的IE用不了toFixed函数，才写了这个
//oldData：原数据
//precision：精度
function toFixedFunc(oldData,precision)
{
if(oldData.indexOf(".")>=0)
{
var diff=oldData.length-(oldData.lastIndexOf(".")+1)
if(diff<=precision)
{
for(var i=0;i<precision-diff;i++)
oldData=oldData+"0";
}
else
{
//四舍五入
oldData=oldData.substring(0,oldData.indexOf(".")+1+precision+1);
var lastNum=parseInt(oldData.substring(oldData.length-1,oldData.length));
oldData=oldData.substring(0,oldData.length-1);
if(lastNum>=5)
{
var newData=parseInt(oldData.substring(0,oldData.indexOf("."))+oldData.substring(oldData.indexOf(".")+1,oldData.length));
newData=newData+1;
oldData=newData.toString();
oldData=oldData.substring(0,oldData.length-precision)+"."+oldData.substring(oldData.length-precision,oldData.length);
}
}
}
else
{
oldData=oldData+".";
for(var i=0;i<precision;i++)
oldData=oldData+"0";
}
return oldData;
}

//去掉空格
//oldStr:原数据
//place:left,right,为空的话去掉左右空格
function trim(oldStr,place)
{
if(place=="left")
newStr=lTrim(oldStr);
if(place=="right")
newStr=rTrim(oldStr);
if(place.length==0)
newStr=lTrim(rTrim(oldStr));
dd.value=newStr;
}
//去掉左边的空格
//oldStr:原数据
function lTrim(oldStr)
{
var beginPlace=0;
var newStr="";
var tmpStr=oldStr.split(" ");
for(var i=0;i<tmpStr.length;i++)
if(tmpStr[i].length>0)
{
beginPlace=i;
break;
}
for(var i=beginPlace;i<tmpStr.length;i++)
newStr=newStr+tmpStr[i]+" ";
return newStr.substring(0,newStr.length-1);
}
//去掉右边的空格
//oldStr:原数据
function rTrim(oldStr)
{
var beginPlace=0;
var newStr="";
var tmpStr=oldStr.split(" ");
for(var i=tmpStr.length-1;i>=0;i--)
if(tmpStr[i].length>0)
{
beginPlace=i;
break;
}
for(var i=0;i<=beginPlace;i++)
newStr=newStr+tmpStr[i]+" ";
return newStr.substring(0,newStr.length-1);
}