restapi express node.js

const express = require('express');
const bodyParser = require('body-parser');

const app = express();

let applications = [];


app.use(bodyParser.urlencoded({extended : true}));
app.use(bodyParser.json());

app.post('/apply', (req, res) => {

    let name = req.body.name;
    let email = req.body.email;
    let phone = req.body.phone;
    let about = req.body.about;

    let application = {id: Math.random().toString(36).substring(2), name: name, email: email, phone: phone, about: about};

    applications.push(application);
    res.send('Your application has been sent')

});


app.get('/all_applications', (req, res) => {
   res.send(applications)
});


app.put('/update/:id', (req, res) => {
    
    let applicant = applications.find(applicant => applicant.id === req.params.id);
    let name = req.body.name || applicant.name;
    let email = req.body.email || applicant.email;
    let phone = req.body.phone || applicant.phone;
    let about = req.body.about || applicant.about;
    let id = applicant.id;

    applications.map(applicant => {
        if(applicant.id === id){
            applicant.name = name;
            applicant.email = email;
            applicant.phone = phone;
            applicant.about = about;
            return applicant
        }
    });

    res.send('Your application has been updated')
});


app.delete('/delete/:id', (req, res) => {
    applications = applications.filter(applicant => applicant.id !== req.params.id);
    res.send('Your application has been removed')
});


app.listen(3000, () => console.log('listening on post 3000'));