Simple math but its not working?

Question

I have a table where users can enter a part number, part price and quantity. It then multiple's the price and the quantity to get you a total. I got this part up and running.

Now i have to get the taxes on the part and then a grand total but this is what im getting:

function calculateit() {
    var myBox1 = $( 'input[name=tax2]:checked' ).val(); //taxes value
    var myBox2 = document.getElementById('partstotalvalue').value; //parts total value
    var result = document.getElementById('partstax'); // input field for the total of taxes * parts
    var myResult = myBox1 * myBox2; //result = taxes * parts total
    result.value = myResult; // display the results

    var result2 = document.getElementById('partstotalwithtax');  // inputp field for taxes + total value
    var totalResult = myResult + myBox2; // totalresult = taxes on part + the parts total
    result2.value = totalResult; // display the results
}

Here's the fiddle:

https://jsfiddle.net/jdarville/hxqev0be/

Looks like you are trying to add strings instead of numbers. — gen_Eric, Sep 07 '16 at 15:37
FYI, when you read values from DOM, they are read as string and not numbers. You will have to manually parse it to number using `parseFloat` or `parseInt`. Also, `+` operator is also a concatination operator for string — Rajesh, Sep 07 '16 at 15:37
@AshokMandal: The code is right there. Why can't you make one? — , Sep 07 '16 at 15:39
Be careful when voting to close: `parseInt` isn't the right solution for a floating point number. — Denys Séguret, Sep 07 '16 at 15:40
@DenysSéguret - That's already addressed in both dupe targets. — BSMP, Sep 07 '16 at 15:41

score 3 · Accepted Answer · answered Sep 07 '16 at 15:39

3

Problem with + operator and variable types.

In your case you try to add string like this

var a = "1" + "2"; <- 12

What you need is to use ParseFloat and then do math

var a = parseFloat("2") + parseFloat("2.14") <- 4.14

Hope this helps.

answered Sep 07 '16 at 15:39

Mykola Borysyuk

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score 0 · Answer 2 · answered Sep 07 '16 at 15:40

0

You could use the unary + operator for casting to Number.

var myBox1 = +$( 'input[name=tax2]:checked' ).val(); //taxes value
var myBox2 = +document.getElementById('partstotalvalue').value; //parts total

answered Sep 07 '16 at 15:40

Nina Scholz

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You should not answer a question which is an obvious duplicate. – Rajesh Sep 07 '16 at 15:42
Why are you hating? – JCD Sep 07 '16 at 15:51
@JCD - no hate here. just stating the facts. – devlin carnate Sep 07 '16 at 15:57
@JCD: Apparently you've never experienced real hate. If you had, you'd never use that word so casually. – Sep 07 '16 at 18:36

Simple math but its not working?

2 Answers2