Finished all exercises in 4-stretch-explore folder

Author: lintsang

Sprint-1/4-stretch-explore/chrome.md

@@ -10,9 +10,18 @@ Let's try an example.
 In the Chrome console,
 invoke the function `alert` with an input string of `"Hello world!"`;
 
+Answer: A modal window pop up showing Hello World! on it.
+
 What effect does calling the `alert` function have?
 
+Answer: When the modal window pop up, user would see message "Hello World!" and has to click OK on the window.
+
 Now try invoking the function `prompt` with a string input of `"What is your name?"` - store the return value of your call to `prompt` in an variable called `myName`.
 
 What effect does calling the `prompt` function have?
+
+Answer: A modal window pop up showing a question 'What is your name?' on it and a input field in shown under it for user to insert the name.
+
 What is the return value of `prompt`?
+
+Answer: 'Undefined' is shown in the return value.

Sprint-1/4-stretch-explore/objects.md

@@ -6,11 +6,22 @@ Open the Chrome devtools Console, type in `console.log` and then hit enter
 
 What output do you get?
 
+Answer: 'ƒ log() { [native code] }' is shown.
+
 Now enter just `console` in the Console, what output do you get back?
 
+Answer: I got 'console {debug: ƒ, error: ƒ, info: ƒ, log: ƒ, warn: ƒ, …}'.
+
 Try also entering `typeof console`
 
+Answer: 'object'.
+
 Answer the following questions:
 
 What does `console` store?
+
+Answer: 'Console' stores the varaiables we declared temporarily until we refresh the page.
+
 What does the syntax `console.log` or `console.assert` mean? In particular, what does the `.` mean?
+
+Both of it has the syntax XXX.XXX at the front is the object and after dot is the method called. So now I know console is the built-in browser object. The dot is the Member Access Operator which make connection or indication between the object and method.