app.use() express code example

Example 1: express redirect

res.redirect('/foo/bar')
res.redirect('http://example.com')
res.redirect(301, 'http://example.com')
res.redirect('../login')

Example 2: express url redirect

const app = require('express')();

// The `res.redirect()` function sends back an HTTP 302 by default.
// When an HTTP client receives a response with status 302, it will send
// an HTTP request to the URL in the response, in this case `/to`
app.get('/from', (req, res) => {
  res.redirect('/to');
});
app.get('/to', (req, res) => res.send('Hello, World!'));

Example 3: what is app.use() used for

//app.get will see only exact match ex.> "/book" here app.get will not allow /book/1, etc 
//but app.use is different see below

//what is difference between app.use and app.all
//app.use takes only 1 callback while app.all takes multiple callbacks
//app.use will only see whether url starts with specified path But, app.all() will match the complete path

app.use( "/book" , middleware);
// will match /book
// will match /book/author
// will match /book/subject

app.all( "/book" , handler);
// will match /book
// won't match /book/author   
// won't match /book/subject    

app.all( "/book/*" , handler);
// won't match /book        
// will match /book/author
// will match /book/subject