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I am new to both Javascript and JSON worlds. I am wondering how I could convert an ining Uint8Array data () to a JS object? Any help / pointers please. Here's what I have done as an experiment.

// arr is uint8Array ining data
function myConvertFunc(arr) {
  let str = "";
  for (var i=0; i<arr.byteLength; i++) {
    str += String.fromCharCode(arr[i]);
  }

  // Say, 'str' at this step looks like below :
  /* {"type": "newEvent", "content": {"rec": [{"id1": "1", "event": "3A=","payload": "EZm9ydW0ub="}]}} */

  var serializedData = JSON.stringify(str);
  let message = JSON.parse(serializedData);

  switch (message.type) {
    case "newEvent":
      log("In newEvent");
      break;
     .
     .
     .
    default:
      log("undefined message type");
  }
}

Contrary to my understanding, the default case log : "undefined message type" is show in my logs. Could someone please help me figure out my mistake here?

I am new to both Javascript and JSON worlds. I am wondering how I could convert an ining Uint8Array data () to a JS object? Any help / pointers please. Here's what I have done as an experiment.

// arr is uint8Array ining data
function myConvertFunc(arr) {
  let str = "";
  for (var i=0; i<arr.byteLength; i++) {
    str += String.fromCharCode(arr[i]);
  }

  // Say, 'str' at this step looks like below :
  /* {"type": "newEvent", "content": {"rec": [{"id1": "1", "event": "3A=","payload": "EZm9ydW0ub="}]}} */

  var serializedData = JSON.stringify(str);
  let message = JSON.parse(serializedData);

  switch (message.type) {
    case "newEvent":
      log("In newEvent");
      break;
     .
     .
     .
    default:
      log("undefined message type");
  }
}

Contrary to my understanding, the default case log : "undefined message type" is show in my logs. Could someone please help me figure out my mistake here?

• javascript
• json

Share Improve this question Follow asked May 24, 2013 at 0:01 SiddarthaSiddartha 13111 gold badge11 silver badge44 bronze badges 4

• 3 What is a "Uint8Array"? – Matt Ball Commented May 24, 2013 at 0:02
• The Uint8Array type represents an array of 8-bit unsigned integers. Not sure if this is the answer you are looking for – Siddartha Commented May 24, 2013 at 0:04
• @MattBall: It's a typed array. See developer.mozilla/en-US/docs/JavaScript/Typed_arrays/… – Bergi Commented May 24, 2013 at 0:13
• 1 @Siddartha: Why do you need to put a JSON string into a typed array (or the other way round)? – Bergi Commented May 24, 2013 at 0:14

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1 Answer 1

Sorted by: Reset to default 5

var serializedData = JSON.stringify(str);
let message = JSON.parse(serializedData);

That means if there are no errors that str === serializedData (or at least two equal-looking objects).

Say, 'str' at this step looks like below:

{"type": "newEvent", "content": {"rec": [{"id1": "1", "event": "3A=","payload": "EZm9ydW0ub="}]}}

Now, if str is the JSON string then you just want

var message = JSON.parse(str);

Currently, you did JSON-encode and then -decode the JSON string, with the result that message was the string again and its type property was undefined.

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