Js中parseFloat()方法所产的精度不一致问题

Js中parseFloat()方法所产的精度不一致问题

<script language="javascript"> 
var a = "0.11"; 
var b = "0.2801"; 
var c = "1.002"; 
var sum1 =parseFloat(a)+parseFloat(b)+parseFloat(c); 
var sum2 =(parseFloat(a)+parseFloat(b)+parseFloat(c)).toFixed(4) 
document.write("a+b+c="+sum1); 
document.write("<br/>") 
document.write("a+b+c="+sum2) 
</script>