<script type="text/javascript">
//parseFloat
function actionoftext(){
var price = 10.99;
var quantity = 7;
var a="18.11";
var b="36.23"
 //54.339999999999996
 
var t=0;
var needPay = parseFloat(a);
    needPay = needPay+parseFloat(b);
	  alert("test"+needPay);
	  document.write("test  "+needPay);
}
 
 
 
</script>
原文:http://www.cnblogs.com/rojas/p/6903308.html