几个Javascript的小工具-JAVA91知识库

几个Javascript的小工具

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//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);
	
}