JavaScript Includes Method

Question

Could someone take a look at this and help me out? I've been working on it for a little while now and can't figure out what I'm missing.

I'm trying to set the inner HTML of a DOM element based upon the presence of a code within the message value of this response object

{
  error: "{\"code\":-1121,\"msg\":\"Invalid symbol.\"}"
  message: "400 - \"{\\\"code\\\":-1121,\\\"msg\\\":\\\"Invalid symbol.\\\"}\""
  name: "StatusCodeError"
  statusCode: 400
}

const data = await res.json();
if (data.statusCode == 400) {
  let parsedData = data.toString();
  if (parsedData.includes('1121')) {
    statusMessage.className = 'alert alert-danger text-center err-message';
    statusMessage.innerHTML = 'Invalid symbol.'

  }
}

A much easier way to check this is to say `if (data.error.code === 1121) { /* do stuff */} ` — mhodges, May 12 '21 at 15:40
@VLAZ the statusMessage element isn't updating although the condition is met but instead defaulting to the else statement (which I forgot to include in the snippet). Regardless, I'm not sure I am using the includes method correctly. — user2079164, May 12 '21 at 15:44
@user2079164 "*although the condition is met*" how do you know it is? Have you tried logging anything? Or debugging? [What is a debugger and how can it help me diagnose problems?](https://stackoverflow.com/q/25385173) — VLAZ, May 12 '21 at 15:45
@user2079164 Please [edit] your question to include a full explanation of the problem. — Heretic Monkey, May 12 '21 at 15:45
@mhodges `data.error.code` is undefined because `data.error` is a string. — Heretic Monkey, May 12 '21 at 15:47
@VLAZ I know it _isn't_ being met because otherwise I wouldn't be here asking for help. I will try to semantically align my comments closer to your preference in the future. Thanks for the link. — user2079164, May 12 '21 at 16:13
@user2079164 the condition being met and an update not happening is *different* to a condition not being met therefore no update is happening. The first means that the `if` check succeeds and the code inside it doesn't work. The second means the `if` check doesn't succeed, so it's the check that fails. Crucial difference. With this in mind *basic debugging* would be to check why `parsedData.includes('1121')` produces unexpected result. Which would lead to checking `parsedData` and the problem becomes immediately apparent. Even a simple `console.log(parsedData)` would have sufficed. — VLAZ, May 12 '21 at 16:20

score 1 · Accepted Answer · answered May 12 '21 at 15:46

data.error is JSON, you should parse it and then check the code property.

const data = await res.json();
if (data.statusCode == 400) {
  let error = JSON.parse(data.error);
  if (error.code == -1121) {
    statusMessage.className = 'alert alert-danger text-center err-message';
    statusMessage.innerHTML = error.msg;

  }
}

XMehdi01 · Answer 2 · 2021-05-12T15:50:14.270

0

Before you parsed the data transform it to JSON format.

let parsedData = JSON.parse(data.error);

Check for a specific property code by using dot notation

if(parsedData.code === -1121))

edited May 12 '21 at 15:50

answered May 12 '21 at 15:41

XMehdi01

5,538
2
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Calling `toString` on an object won't give you JSON – Quentin May 12 '21 at 15:43
I didn't pay attention to that just meant `data.error` not `data.toString()`, check the __UPDATE__ – XMehdi01 May 12 '21 at 15:53

Caroline Mwasigala · Answer 3 · 2021-05-12T15:50:09.287

-1

The parsedData checked should be the message not the whole data

var data={
  error: "{\"code\":-1121,\"msg\":\"Invalid symbol.\"}",
  message: "400 - \"{\\\"code\\\":-1121,\\\"msg\\\":\\\"Invalid symbol.\\\"}\"",
  name: "StatusCodeError",
  statusCode: 400,
}


if (data.statusCode == 400) {
  let parsedData = data.message.toString();
  if (parsedData.includes('1121')) {
   console.log('alert alert-danger text-center err-message');
    console.log('Invalid symbol.')}
  }

edited May 12 '21 at 15:50

answered May 12 '21 at 15:41

Caroline Mwasigala

134
2
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That is because he hasn't posted full code and you are trying to run it inside a snippet – Nisanth Reddy May 12 '21 at 15:42

JavaScript Includes Method

3 Answers3