Exam 70-480 topic 4 question 82 discussion

Actual exam question from Microsoft's 70-480

Question #: 82
Topic #: 4

[All 70-480 Questions]

You have the following code:

You need to convert objStr into an array.
Which line of code should you use?

A. var jsObject = Array.bind(objStr);
B. var jsObject = Array.valueOf(objStr);
C. var jsObject = JSON.parse(objStr);
D. var jsObject = $.makeArray(objStr);

Show Suggested Answer

Suggested Answer: C 🗳️
https://www.w3schools.com/js/js_json_parse.asp

by Bart_v_M at Dec. 11, 2020, 12:22 p.m.

Comments

Submit Cancel

AnetteK

4 years, 5 months ago

yeah seems weird but I guess this is the reason why it works: "When using the JSON.parse() on a JSON derived from an array, the method will return a JavaScript array, instead of a JavaScript object."

upvoted 1 times

...

Okay, I now also tested C. And I have to admit that this should be the correct answer. I didn't expect this at first because the string "[1, 2, 3, 4]" is not in Javascript Object Notation, like '{ "name":"James", "age":34, "city":"Jamestown"}'. Below you can see my test code: <script> var objStr = "[1, 2, 3, 4]"; var json = JSON.parse(objStr); for (var i in json) { alert(json[i]); } </script>

upvoted 1 times

...

Bart_v_M

4 years, 6 months ago

I think answer D should be the correct answer, not C. See: https://api.jquery.com/jquery.makearray/

upvoted 1 times

Bart_v_M

4 years, 6 months ago

I've tested it and it does create an array, however it doesn't automatically split the elements (the numbers) in the string, of course...

upvoted 1 times

Bart_v_M

4 years, 6 months ago

Therefore you could use the following JavaScript: <script src="../jquery.js"></script> <script> window.onload = function () { var objStr = "[1, 2, 3, 4]"; var jsObject = $.makeArray(objStr.replace("[", "").replace("]", "").split(", ")); alert($.isArray("jsObject is array: " + jsObject)); for (var i in jsObject) { alert(jsObject[i]); } } </script>

upvoted 1 times

...