How to remove the 0 at the start in javascript?

Question

I was getting this error in the console.


core.js:6014 ERROR SyntaxError: Unexpected number in JSON at position 2
    at JSON.parse (<anonymous>)
    at SafeSubscriber.httpObj.userService.getTaxRate.subscribe.httpObj [as _next] (geotax.component.ts:404)
    at SafeSubscriber.__tryOrUnsub (Subscriber.js:183)
    at SafeSubscriber.next (Subscriber.js:122)
    at Subscriber._next (Subscriber.js:72)
    at Subscriber.next (Subscriber.js:49)
    at MapSubscriber._next (map.js:35)
    at MapSubscriber.next (Subscriber.js:49)
    at FilterSubscriber._next (filter.js:33)
    at FilterSubscriber.next (Subscriber.js:49)

When i debug the code i found out that this was coming because the sevice which was returning a latitude, was appending 0 at the start . Example latitude = "-048.55" instead of latitude="-48.55".
How can i remove this '0' at the start of this latitude?

You should fix the service so it returns valid JSON instead of trying to hack invalid JSON after it arrives on the client. — Quentin, Apr 12 '20 at 11:05
This is specific to some cases as sometimes valid json is coming — sunny, Apr 12 '20 at 11:07
I assume the cases it is specific to are ones where the latitude is between -100 and +100 (not inclusive). You should still fix the code generating the invalid JSON and not try to hack it once it gets to the client. — Quentin, Apr 12 '20 at 11:08
maybe a number type would help better for stringify than a string. — Nina Scholz, Apr 12 '20 at 11:09
The JSON endpoint should be fixed: it's not something you can do much on your end. That's because JSON cannot support leading zeros in numbers, as leading zeros indicate an octal number: https://stackoverflow.com/questions/27361565/why-is-json-invalid-if-an-integer-begins-with-a-leading-zero. Since octal numbers cannot contain '8', then `-048.55` will throw an error as `JSON.parse` fails to parse an invalid octet. — Terry, Apr 12 '20 at 11:11

score 1 · Accepted Answer · answered Apr 12 '20 at 11:19

1

You can clean the data before processing using helper function like below -

let coordinates = [{
    latitude: '56.56'
  },
  {
    latitude: '-048.55'
  }
];

let cleanData = (data = []) => {
  return data.map(item => {
      return {
        ...item,
        latitude: Number(item.latitude).toString()
      }
  })
}

console.log(cleanData(coordinates));

answered Apr 12 '20 at 11:19

Varun Goel

435
2
7

1

It is not that simple. OP gets the data as an invalid JSON *string* which you cannot just parse with `JSON.parse`. You would have to fix the string first. – str Apr 12 '20 at 11:21
In that case a reviver function may help.We can transform the data before it is returned. https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse – Varun Goel Apr 12 '20 at 11:41
Even using a reviver function, you cannot parse invalid JSON. – str Apr 12 '20 at 12:09
Fixing the inccorect JSON response from source is the best choice left rathar adding any patches then. – Varun Goel Apr 12 '20 at 15:47

How to remove the 0 at the start in javascript?

1 Answers1