Angular 6: SyntaxError: Unexpected token O in JSON at position 0 at JSON.parse with valid JSON

Question

I am not sure whether my function is wrong, which should send data to the server, or the function on the server is wrong. I looked up similar questions but the solution I adopted to my problem did not work.

My function looks like this:

postData(number){
   let array = JSON.stringify(this.locArr);
   return this.http.post<any>(this.url, array)
    .subscribe(),
    error => console.log("Error: ", error)
    }

JSON which is send:

[ 
  { 
      "id":222,
      "name":"Lars",
      "sLA":37
   },
  { 
      "id":223,
      "name":"Sim",
      "sLA":12
   }
]

All parameters like token etc. are received by the server function but the array I wrote above is null, although it is valid json. I wonder why this error is occuring.

Any advice is appreciated

this json is invalid . please check your json : jsonlint.com — Joel Joseph
– Joel Joseph, Commented Nov 15, 2019 at 7:43
sorry, I changed it, forgot to remove the coma. Now it should be valid json. — Cara
– Cara, Commented Nov 15, 2019 at 7:45
also you are posting an array to the server which is not valid json or more like text. you should be posting it as json object — Joel Joseph
– Joel Joseph, Commented Nov 15, 2019 at 7:49
I am not sure what you mean. The array above is valid json? I checked it with a validator, or do you mean something else? — Cara
– Cara, Commented Nov 15, 2019 at 7:55
I tried it with Object.assign and send it as a JSON object but it is still not working.. — Cara
– Cara, Commented Nov 15, 2019 at 8:02

Morsh · Accepted Answer · 2019-11-15 08:07:48Z

0

The local array will be converted into JSON automatically by Angular, you need not stringify or parse it.

postData(number){
    this.http.post<any>(this.url, this.locArr)
    .subscribe((data)=>{
        //code after receiving data from server
    },
        error => console.log("Error: ", error))
}

answered Nov 15, 2019 at 8:07

Morsh

3413 silver badges5 bronze badges

Sign up to request clarification or add additional context in comments.

Comments

Joel Joseph · Accepted Answer · 2019-11-15 08:15:11Z

0

I believe you are using httpClientModule so then there is no need of tyou need't JSON.stringify remove this step JSON.stringify(this.locArr);
Also you need to send it as json object {} not json array []

postData($locArr){ // pass the array to the service function
   let data = { data : $locArr}; // note that you have to post it as json object {} not []
   return this.http.post<any>(this.url,data);
}

answered Nov 15, 2019 at 8:15

Joel Joseph

6,1974 gold badges34 silver badges37 bronze badges

2 Comments

Joel Joseph Over a year ago

@Cara please check this

Cara Over a year ago

Hey, thank you for your answere! I think it is a server side error. I will try it!

Collectives™ on Stack Overflow

Angular 6: SyntaxError: Unexpected token O in JSON at position 0 at JSON.parse with valid JSON

2 Answers 2

Comments

2 Comments

Linked

Hot Network Questions

Collectives™ on Stack Overflow

2 Answers 2

Comments

2 Comments

Linked

Related