jQuery-如何将NaN更改为其他内容

Question

I have a function that displays a numerical total of various dropdowns. If one of the dropdowns is set to # (the starting value), the resulting value is displayed as NaN.

I want to change how NaN is displayed on my page. I want it to read "--" instead of "NaN".

Here is the function with variables and if/elses omitted:

function multiply() {
    $('#total').text((((beds * perhour) + (addbath)) * discount ));
}

How can I set the text to -- instead of NaN ?

Answer 1

An easy fix is to use the fact that NaN is a falsy value

function multiply() {
    $('#total').text(((((beds * perhour) + (addbath)) * discount)) || 0);//instead of 0 you can pass any default value here like an empty string
}

Answer 2

You can use isNaN() to compare if you got number or NaN, you can use ternary conditional operator to get assign result or string constant "--" to div.

result = isNaN((((beds * perhour) + (addbath)) * discount ))
$('#total').text(isNaN((result) ? "--" : result) 

Answer 3

function multiply() {
    var total = ((beds * perhour) + (addbath)) * discount; 
    $('#total').text(!isNan(total) ? total : '--');
}

Answer 4

You can use isNumeric function in jquery,

 $.isNumeric(NaN);    // false

Refer this, http://api.jquery.com/jQuery.isNumeric/