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I am making an http request from ionic app(Angular4) and receiving a response in form of a Js object, but on receiving i am getting some error.

This is the object which i am receiving from API

{"up_votes":"1","down_votes":"0"}

using http.get to receive data in app, home.ts

..
public vote_response:any={};
...
this.http.get(this.baseURI+'votesNum.php?'+this.question.question_id)
        .subscribe(result =>{this.vote_response = result.json();});

this is the error which i am receiving:

ERROR SyntaxError: Unexpected token < in JSON at position 0
    at JSON.parse (<anonymous>)
    at Response.Body.json (http.es5.js:800)
    at MapSubscriber.project (forum-quest-details.ts:44)
    at MapSubscriber._next (map.js:77)
    at MapSubscriber.Subscriber.next (Subscriber.js:89)
    at XMLHttpRequest.onLoad (http.es5.js:1229)
    at t.invokeTask (polyfills.js:3)
    at Object.onInvokeTask (core.es5.js:4119)
    at t.invokeTask (polyfills.js:3)
    at r.runTask (polyfills.js:3)

Can anyone help me solve this issue.

herehere
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  • You are probably not receiving the object you think. Debug the code and check. – Arg0n Jun 05 '17 at 08:11
  • Arg0n has a point. It is possible you are receiving and xml. Something hints on the first character being "<" – Khan Jun 05 '17 at 08:12
  • Try JSON.stringify the result and console.log it, and then see what it says. It could be several things like your parameters are wrong and its sending an html page in return or something – Chris Jun 05 '17 at 08:13
  • I think with that request you are fetching a php file instead of a JSON string, that's why you get `<` at position `0`. You should check if the url `this.baseURI+'votesNum.php?'+this.question.question_id` is correct. – cнŝdk Jun 05 '17 at 08:26
  • Yes you are correct Arg0n. I am getting this is the output for console.log(res) the **_body**: `
    ↵Notice: Undefined index: question_id in C:\xampp\htdocs\success\team\votesNum.php on line 5
    ↵{"up_votes":"0","down_votes":"0"}` I am getting the response from php server by using `echo json_encode(array('up_votes'=>$up_votes, 'down_votes'=> $down_votes ));` can anyone tell how to solve this ?     – herehere Jun 05 '17 at 08:56
  • [**This**](https://stackoverflow.com/questions/4064444/returning-json-from-a-php-script) may help here. – cнŝdk Jun 05 '17 at 09:12

1 Answers1

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this.vote_response = result.json();

Replace this one with console.log(result) and take the data and check with some online JSON validation site (https://jsonlint.com) to see if the data is valid JSON. You might be getting HTML body instead of JSON.

To response as JSON: 

header('Content-Type: application/json');
echo  json_encode(array('up_votes'=>$up_votes, 'down_votes'=> $down_votes ));
serkan
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  • Yes you are correct. I am getting this is the output for console.log(res) the _body:
    ↵Notice: Undefined index: question_id in C:\xampp\htdocs\success\team\votesNum.php on line 5
    ↵{"up_votes":"0","down_votes":"0"} I am getting the response from php server by using echo json_encode(array('up_votes'=>$up_votes, 'down_votes'=> $down_votes )); can anyone tell how to solve this ?     – herehere Jun 05 '17 at 08:57