删除变量时从输入字段中删除NaN

Question

I'm making a simple calculator and i have a bit of code that i got from a previous question:

$("input[type=text]").keyup(function () {
        var number = parseFloat($(this).val());
        var inc = parseFloat($(this).attr("inc"));
        var newValue = number / inc;
        $("input[type=text]").each(function () {
                $(this).val(newValue * parseFloat($(this).attr("inc")));
                });
        });

When i enter a value then delete it the box's equal NaN, i just need to know how to stop it from displaying it and display 0 in its place.

JSFiddle Here

Answer 1

You can use isNaN(val) : to check if its number is illegal.

$("input[type=text]").each(function () {
if(isNaN(newValue * parseFloat($(this).attr("inc"))))
  $(this).val(0);
else
  $(this).val(newValue * parseFloat($(this).attr("inc")));
});

Working Demo

Answer 2

Test if the number if NaN before using it:

var number = parseFloat($(this).val());
if (isNaN(number)) {
    number = 0;
}

Answer 3

Test the value using isNaN() this will allow you to alter the output

http://jsfiddle.net/J24yN/153/

        newValue * parseFloat($(this).attr("inc"))

        if(!isNaN(newValue)){
            $(this).val(newValue);
        } else {
            $(this).val(0);
        }