How to keep value as number in JSON.stringify()

Question

I'm trying to use JSON.stringify() to parse some values into JSON format. That amount is a string variable.I want the final value in JSON format as a number, but my current way doesn't work. It still comes out as "price":"1.00" after JSON.stringify() . How do I make sure the final value in JSON is a number? Thanks for your help!

My current code:

var data = JSON.stringify({
 "payer": "a cat",     
 "price": parseFloat(amount).toFixed(2),

});

So why are you converting it to a string with toFixed? – epascarello Jan 12 '17 at 22:50 — epascarello, Jan 12 '17 at 22:50

score 11 · Accepted Answer · answered Jan 12 '17 at 22:47

11

toFixed returns a string. If you want to output a number, just use parseFloat:

JSON.stringify({
  "payer": "a cat",
  "price": parseFloat(amount)
});

I don't think there's a way to output a number to any precision after the decimal without converting it to a string.

answered Jan 12 '17 at 22:47

Cappielung

322
3
6

2

Or just `+amount`. – RobG Jan 12 '17 at 23:12
1

multiply, floor/round/ceil, divide – juanitogan Sep 28 '20 at 00:42

score 4 · Answer 2 · answered Oct 18 '19 at 10:19

4

I think Number() will work too

The differences are here. I have worked with both in JSON.stringify

var data = JSON.stringify({
  "payer": "a cat",
  "price": Number(amount)
});

answered Oct 18 '19 at 10:19

Stavros

743
8
19

score 0 · Answer 3 · answered Oct 26 '17 at 13:09

I had the same problem, creating random float number, this is my solution:

// Create a random float number between 10 and 120, with only 2 decimal place
var number = Math.floor((Math.random()*110+10)*100)/100

So is still a floating value, with 2 decimal place, also after JSON.stringify()

score 0 · Answer 4 · answered Jul 14 '21 at 21:13

0

This way has served me.

function replace(key, value) {
  if (typeof value != "object") {
    let change = parseFloat(value);
    return change;
  }
  return value;
}

const msg = JSON.stringify(params, replace);`

Params is a variable that contains a query parameter.

answered Jul 14 '21 at 21:13

Ezequiel Larena

1
1

Won't this try to convert every string to float, whether the string contains a number or not? – Marco Castanho Sep 26 '21 at 13:36
Yes. In case you want to avoid that, you should add another validation. – Ezequiel Larena Sep 27 '21 at 15:34

score 0 · Answer 5 · answered Aug 01 '22 at 13:05

0

JSON.stringify(obj, (key, value) => {
    if (!isNaN(value))
        value = Number(value)
    return value
})

answered Aug 01 '22 at 13:05

Fliens

19
1
7

How to keep value as number in JSON.stringify()

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