How to get specific data from object array?

A few points:

• data is not an array, is an Object (see the curly braces, arrays have squared brackets). To be really precise, your syntax is invalid, but I assume you wanted to type data = { ... }, as opposed to data { ... }
• Your syntax is almost correct, the only mistake you are making is that userinfo is an array, and arrays have numeric indexes (I.e. array[0], array[1]). What you are looking for is this.data.orderid.userinfo[0].status

Use data.userinfo[0].status to get the value (in your case this.data.userinfo[0].status)

var data = {
    "orderid": 5,
    "orderdate": "testurl.com",
    "username": "chris",
    "email": "",
    "userinfo": [
      {
        "status": "processing",
        "duedate": "" ,
      }
    ]
  };
  console.log(data.userinfo[0].status);

User Info is an array, so you would need to access it using indexer like so:

return this.data.userinfo[0].status

MDN on arrays: https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array

You need to iterate over data.userinfo (it's an array)

var data = {
    "orderid": 5,
    "orderdate": "testurl.com",
    "username": "chris",
    "email": "",
    "userinfo": [
      {
        "status": "processing",
        "duedate": "" ,
      }
    ]
  };
  
data.userinfo.forEach(function(element) {
  console.log(element.status);
});