NodeJS Server

// Express Js Object Last Main Initilized with ()
const app = require('express')();

// Body Parser Only Library Imported
const bodyParser = require('body-parser');

// Telling App To Use Body Parser
app.use(bodyParser.json());


// Note - Every route get or post needs (req,res)
// So it is must to use

// Base Url Method Most Basic Method of routing
app.get("/",(req,res)=>{
    res.send("<h1>Hello World!</h1>");
});

// URL with URL Embeded Paramerters Method
//  Here name is subblied in URL
// And Can be accessed using req.prams.name
app.get("/greet/:name",(req,res)=>{
    const name = req.params.name;
    res.send("Hello : "+name);
});

// Querry Parameters Are Supplied after a ?
// They state not essential data from client
// It can be accessed using req.query.variableName
app.get("/greet2/:name",(req,res)=>{
    const name = req.params.name;
    const surname = req.query.sname;
    res.send("Hello 2 : "+name+" "+surname);
});


// Just like get post method is there
// Post method is secured and is utilized for
// Login and other confedinital work
// You can access post data using body-parser
// app.body.variableName

app.post("/login",(req,res)=>{

    console.log(req.body);

    const user = req.body.userId;
    const password = req.body.password;

    if(password == "1234"){
        res.send("Logged In");
    }
    else{
        res.send("Invalid Username And Password");
    }

});

// By default if path is called get route always respond first
app.get("/login",(req,res)=>{
    console.log("Login Get Called");
    res.send("Wrong Address");
});

// Here we are telling our app object defined in
// Line number 1 to listen or work in which port
// This can be any number in this case 3000
app.listen(3000,()=>{
    console.log("Server Is Running");
}
);