Web Development

Question 1

For the following HTTP request, what line of code will be launched on the server?

POST/login HTTP/1.1

• app.post(‘/login’, …)
• app.post(‘/login/:id’, …)
• app.delete(‘/users/:id’, …)
• app.get(‘/login’, …)

Answer 1

app.post(‘/login’, …)

Question 2

In the following list, please check what is NOT an existing HTTP method:

• PUT
• GET
• DELETE
• CHANGE

Answer 2

Change

Question 3

What is the total number of ports available on a server?

• 128 000
• 64 000
• 65 536
• 128 796

Answer 3

65 536 (from 0-65535)

Question 4

What are the ‘well-known ports” you cannot use for your own server becase they are reserved for web services?
* 0 to 1023
* 1024 to 49151
* 800 to 2048
* 8080 to 65535

Answer 4

0 to 1023, for example well known ports: 443 https, 80 http, 21 jtp

Question 5

What famous name is associated with IP address 127.0.0.1?
* host-local
* hostlocal
* local-host
* localhost

Answer 5

• localhost

localhost or loopback is your own computer. If you can “ping 127.0.0.1”, it means TCP/IP is up and running on your own computer!

Question 6

Considering the HTML and CSS codes given:

<div>
My website is cool!
</div>

—————————————————————#textgreen {
color: green;
}

.textred {
color: red;
}
—————————————————————What is the color of the line -My website is cool!-?
* green
* A mix between red and green
* red
* violet

Answer 6

green,
the ID has higher priority than the class

Question 7

Considering the HTML code given:

<div>
My website is <span>cool</span>!
</div>

What is the simplest possible code to make the text -cool- orange?

• .textred span { color: orange; }
• .textorange { color: orange; }
• # textorange { color: orange; }
• # textgreen span { color: orange; }

Answer 7

textorange { color: orange; }

Direct and simple!

Question 8

Considering the HTML and CSS codes given:

<div>
<span>This text is in
a frame...</span>
</div>

.framedtext {
border: 3px solid red;
}

The result is not satisfying because the text touches the border. I want to add a 8px space between the border and the text, which alternative is correct?

• border-radius: 8px;
• box-sizing: border-box;
• margin: 8px;
• padding: 8px;

Answer 8

padding: 8px;

Padding is the gap between a border and a box content.

Question 9

A function that you declare in a Javascript program but you do not call yourself is called:

• A callback function
• A standalone function
• A system call function
• A basic function

Answer 9

A callback function
It is “called back” when a certain event occurs

Question 10

What is the text needed to replace ZZZ in the following code to get the list of index and role:

app.get(‘/roles2’, function (req, res) {
const persons=[
{“id”: “1”, “name”:”Mira”, “role”: “Lab Assistant”}, {“id”: “2”, “name”:”Susanne”, “role”: “Lecturer”}, {“id”: “3”, “name”:”Jasmin”, “role”: “Lecturer”}, {“id”: “4”, “name”:”Linus”, “role”: “Lecturer, Lab Assistant”}, {“id”: “5”, “name”:”Jerome”, “role”: “Lecturer, Lab Assistant”}
]

myText = “”
persons.forEach( ( ZZZ ) => {
myText += “<li>“+p.id+”: “+p.name+”</li>”
})
res.send(“<ul>“+myText+”</ul>”)
})

The expected result:
* 1: Mira
* 2: Susanne
* 3: Jasmin
* 4: Linus
* 5: Jerome

Select one alternative to replace ZZZ:
*myText
*roles
*p
*persons

Answer 10

p, We use p.id and p.name, so it is “p” that must be used in the forEach

Question 11

In my code, I want to extract all the fields (I have five fields in my table) from the table -projects-, what is the good code to execute to get the answer?

*db.all(“SELECT * FROM projects”, (error, theProjects) => { … })
* db.all(“SELECT projID, projName FROM projects”, (error, theProjects) => {…})
* db.run(“SELECT projID, projName FROM projects”, (error, theProjects) => {…})
* db.all(“SELECT * FROM Projects”, (error, theProjects) => {…})

Answer 11

• db.all(“SELECT * FROM projects”, (error, theProjects) => {…})

The table name is case sensitive!

Question 12

What is the correct code to change the year to “2023” of my project number (projectId) 4?

• UPDATE projects SET projectYear=”2023” WHERE project=4
• UPDATE projects SET projectYear=”2023” WHERE projectId=4
  *UPDATE projects/4 SET projectYear=”2023”
  *UPDATE projects SET projectYear=”2023”

Answer 12

• UPDATE projects SET projectYear=”2023” WHERE projectId=4

Question 13

If you delete your node_modules directory and you want to reinstall all the needed packages for your application. In which file npm will find the packages to install when the command “npm install” is run in the terminal?

• package.json
• main.handlebars
• package-lock.json
• app.js

Answer 13

package.json

This file contains all the dependencies of your project!

Question 14

Where are the packages installed when you use “npm install nameOfPackage”?

• Node-Modules/
• Node_Modules/
• node_modules/
• node-modules/

Answer 14

• node_modules/

The name contains only lowercase letters!

Question 15

Consider the following code:

app.get(‘/’, (req, res) => {
res.render(‘home’);
})

Rewrite the code with the function notation instead of the => notation

Answer 15

app.get(‘/’, function(req, res){
res.render(‘home’);
});

Question 16

var port = 8080
const app = express();
var port = 3333
app.listen(port, () => {
console.log(Server listening on port ${port})
})
Write the EXACT text (be careful of upper case and lower case characters in the string) written on the console when the program is run here:

Answer 16

Server listening on port 3333

Last defined value

Question 17

app.use((req, res, next) => {
console.log(“Req. URL: “, req.url)
next()
})

What is this full code called?

• A component
• A middleware
• A callback function
• A central function

Answer 17

• A middleware
  A function that will be called automatically at each coming request

Question 18

We consider we ask the user the id of the project he/she wants to see using a form. This id is put in the variable pid. Why does the following code is a security issue?

db.run(“SELECT * FROM projects WHERE id=”+pid, (error) => {
if(error) {console.log(“ERROR: “, error) }
else { console.log(“I got the result from the projects table!”)}
})

• The pid is not a number
• The pid is a number
• The pid is empty
• The pid can contain a string with corrupted inserted SQL code

Answer 18

The pid can contain a string with corrupted inserted SQL code

That is why we have the “?” notation when we write a parameter in our SQL queries!