Week - 5

Question 1

HTML:

JS 1:
console.log(document.getElementById(“name”).value
+ “ Coursera!”);
JS 2:
console.log(document.querySelector(“#name”).value
+ “ Coursera!”);
What will be the difference in the output between the 2 Javascript code snippets?

Answer 1

No difference
Both methods are valid. The querySelector method expects a CSS query, so the ‘#’ sign is therefore needed before referencing a value of an ‘id’ attribute.

Question 2

CODE:
…

document.addEventListener(“DOMContentLoaded”, function(event) {
console.log(“Yey!”);
});

…

<h1>Hello!</h1>

Answer 2

It will output Yey! when the web page is loaded, but before external resources like images are downloaded to the user’s machine.

Question 3

One of the differences between a GET request and POST is that a GET request passes query parameters as part of the URL whereas POST request passes them as part of the body of the request.

Answer 3

True

Question 4

JS:
var name = "";
// Making an Ajax call here, i.e., sendGetRequest
$ajaxUtils.sendGetRequest("someURL", function (request) {
  name = "Coursera";
});

document.querySelector(“#content”).innerHTML = name;
What will be the contents of the element with the ‘id’ value of ‘content’ after the execution of this Javascript code?

Answer 4

It will be empty.
The setting of the ‘name’ to ‘Coursera’ will happen AFTER the assigning of innerHTML when the ‘name’ variable still contains an empty string.

Question 5

Another name for Object Literal is JSON.

Answer 5

False

JSON is a string, Object Literal is a way of creating a real object in Javascript.

Question 6

Identify invalid JSON string below:
1. '{
  "courseName": "Coursera",
  "startingNumberOfStudents": 12500
}'
2. '{
  "courseName": "Coursera",
  "studentsLoveCourse": true
}'
3. '{
  'courseName': "Coursera",
  'startingNumberOfStudents': 12500
}'
4. '{
  "courseName": {"name": "Coursera"},
  "startingNumberOfStudents": 12500
}'

Answer 6

Option 3 as single quotes are not allowed in JSON.