How to CONCAT 0 with number

Question

I have 2 input box value `"bill_amount" with value 1250, "xray" with value 0

when i tried to find the sum it returns 12500 but when i tried to find the subtracted value it returns 1250 . why for addition it concat 0 while subtraction not including 0.

And how to avoid that?

 console.log( document.getElementById("bill_amount").value-document.getElementById("xray").value);

Cast it to the number before performing arithmetic operations. Use `Number(value)` or simply `+value` — abhishekkannojia, Jul 10 '17 at 10:59
I think your value will be in string format so use parseInt() — Nair Athul, Jul 10 '17 at 11:00

Milan Chheda · Answer 1 · 2017-07-10T11:07:18.963

0

You need to parse your values using parseFloat():

function calculate() {
  console.log(parseFloat(document.getElementById("bill_amount").value) - parseFloat(document.getElementById("xray").value));
}

<input type='text' id='bill_amount' />
<input type='text' id='xray' />
<button onclick="calculate()">Calculate</button>

edited Jul 10 '17 at 11:07

answered Jul 10 '17 at 11:00

Milan Chheda

8,159
3
20
35

score 0 · Answer 2 · answered Jul 10 '17 at 11:00

0

- converts strings to numbers:

"1250" - "0" => 1250

+ does not:

"1250" + "0" => "12500"

So may convert first:

+"1250" +" 0" => 1250

answered Jul 10 '17 at 11:00

Jonas Wilms

132,000
20
149
151

score 0 · Answer 3 · answered Jul 10 '17 at 11:02

You need to parse your values as numbers:

var billAmount = document.getElementById("bill_amount");
var xray = document.getElementById("xray");
var calculate = document.getElementById("calculate");

calculate.onclick = function() {
  console.log(parseFloat(billAmount.value, 10) - parseFloat(xray.value, 10));
}

<input id="bill_amount" type="number" min="0" value="1250" step="0.0001"/>
<input id="xray" type="number" min="0" value="0" step="0.0001"/>
<input id="calculate" type="button" value="calculate" />

score 0 · Answer 4 · answered Jul 10 '17 at 11:06

0

 console.log(eval( document.getElementById("bill_amount").value-document.getElementById("xray").value));

Try this

answered Jul 10 '17 at 11:06

Anubrij Chandra

1,592
2
14
22

How to CONCAT 0 with number

4 Answers4