w3

Question 1

What is Express?

Answer 1

Express is a web application framework for Node.js.

provides all of the tools and basic building blocks you need to get a web server up and running by writing very little code.

allowing us to focus on the application’s logic and content.

Question 2

In express what do we not have to do that in node.js we do?

Answer 2

we don’t need to-

specify the response headers 200,400 or

add a new line at the end of the string because the framework does it for us.

Question 3

URL routing

app.get(‘/ab?cd’, function (req, res) {
res.send(‘ab?cd’)
})

Answer 3

This route path will match acd and abcd.

b is silent

Question 4

app.get(‘/ab+cd’, function (req, res) {
res.send(‘ab+cd’)
})

Answer 4

This route path will match abcd, abbcd, abbbcd, and so on

b can be any number of letters

Question 5

app.get(‘/abcd’, function (req, res) {
res.send(‘abcd’)
})

Answer 5

This route path will match abcd, abxcd, abRANDOMcd, ab123cd, and so on.

Question 6

app.get(‘/ab(cd)?e’, function (req, res) {
res.send(‘ab(cd)?e’)
})

Answer 6

This route path will match /abe and /abcde.

cd is silent

Question 7

app.get(/a/, function (req, res) {
res.send(‘/a/’)
})

Answer 7

This route path will match anything with an “a” in it.

Question 8

app.get(/.fly$/, function (req, res) {
res.send(‘/.fly$/’)
})

Answer 8

This route path will match butterfly and dragonfly, but not butterflyman, dragonflyman, and so on.

Question 9

Router parameters

Answer 9

Route parameters are named URL segments that are used to capture the values specified at their position in the URL. The captured values are populated in the req.params object, with the name of the route parameter specified in the path as their respective keys.

Question 10

Query string

Answer 10

To get the list of query string parameters in a route, req.query can be used

Question 11

Router parameters vs query string

Answer 11

Router parameters- req.param object

Query string- req.query

Question 12

Router-level middleware use?

Answer 12

For the sake of separation of concerns (SoC) and maintainability,

t is possible to separate the routes from the main js file using Express.Router

Question 13

In order to accept requests with a path that starts with BI, ends with DX, and zero or more characters in between, we have to use:

Answer 13

app.get(‘/BI*DX, function(res,res){

});

Question 14

Assume you have this fragment of code

app.get(‘/item’, function (req, res) {
// print out the item id
})

and the client sends this request:

http://localhost:8080/item?id=123

Which statement prints the value of the id to the console?

Answer 14

console.log(req.query.id)

Question 15

Assume you have this fragment of code:

app.get(‘/item(w2)?warehouse’, function(req, res){
res.send(‘We got a match’);
})

This route path will match:

Answer 15

/itemwarehouse and /itemw2warehouse

Question 16

Assume you have this fragment of code:

app.get(‘/items/:itemid’, function (req, res) {
//do something
})

The data type of req.params is:

Answer 16

object