jQuery calculation NaN | 易学教程

问题

I have a view that output decimal values that represent money data types on the database. To output I am using the following formatting code

string price = String.Format("{0:f}", (item.Price + item.VAT));

that produce a string like this

12,99 (with comma as the decimal separator)

I am now using this string to make some calculation on the client using jQuery

elmProductSelected.children("option").each(function(n) {
    var pIdx = $(this).attr("rel"); 
    var pObj = products.eq(pIdx);
    var pValue = $(this).attr("value");
    var valueArray = pValue.split('|');
    var prdId = valueArray[0];
    var pQty = valueArray[1];
    /* the value of pPrice is 12,99 after the following call */
    var pPrice =  $(pObj).attr(attrProductPrice);
    /* I get NaN here! */
    sTotal = sTotal + ((pPrice - 0) * (pQty - 0));
    cProductCount++;
    cItemCount = cItemCount + (pQty-0);
});

I am getting NaN right on the line I have commented. I suppose that this is due to the fact that the pPrice value use the comma as the decimal separator because if I manually set it as 12.99 everything works.

Is there a way to read the 12,99 as a number using javascript/jQuery?

回答1:

NaN = Not a number

By using parseInt you can tell Javascript that it should be treated as a number.

var pPrice = parseInt($(pObj).attr(attrProductPrice));

You might need parseFloat if you're using a decimal.

回答2:

There are two problems with the code. First, you should cast the string to float, as Webnet suggests. The parseFloat function, however, will expect the argument to use dot as a decimal separator. Therefore, the following code will do what you want:

var pPrice = $(pObj).attr(attrProductPrice);
pPrice = parseFloat(pPrice.replace(',', '.'));

First, you replace the comma for a dot, then convert the result to a float.

回答3:

If that's the only comma separator there will be (none for a thousands separator), then just replace it.

var num = parseInt( str.replace( ',', '.' ) ); // or parseFloat

If there are other characters that will prevent correct parsing, then I'd suggest having a custom attribute that stores the undecorated number.

<input data-undecorated="123.45" value="123,45" />

var num = parseInt( $('#myInput').data('undecorated') ); // or parseFloat

You can use data() like this to get data- attributes if you're using jQuery 1.4.3 or later.

回答4:

try this

var pPrice = $(pObj).attr(attrProductPrice).split(",").join(".");

回答5:

Try this RegEx:

Update: Changed the expression, since I missed the part(with comma as the decimal separator).

var pPrice = $(pObj).attr(attrProductPrice)..replace(/(,)(\d+)$/, ".$2").replace(",","")

回答6:

This looks related: How to convert string into float in javascript?

It looks like you'll have to replace the comma with a decimal.

parseFloat('12,99'.replace(',', '.'))

来源：https://stackoverflow.com/questions/4542012/jquery-calculation-nan

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