how can we write a perfect menu driven program using switch case in node js

Asked Mar 29 '17 at 05:54

Active Mar 29 '17 at 05:54

Viewed 938 times

I want to write something like this

var rl = readline.createInterface({
input: process.stdin,
output: process.stdout,
});
r1.setprompt('press 1 to load fle, press 2 to exit');
rl.prompt();

rl.on('line', (line) => {

switch(line.trim()) {
  case '1':
    r1.setPrompt('Enter file name to add');
    r1.prompt()
    r1.on('line',(filename)=>{
        settings = JSON.parse(fs.readFileSync(filename, 'utf8'));
    });
    break;
    case '2':
    console.log('Exit');
    process.exit(0);
    break;
  default:
    console.log(`Invalid command '${line.trim()}'`);
    break;
   }
 rl.prompt();
 }).on('close', () => {
process.exit(0);
});

I want the menu to be flashed again and again until user selects option 2. what I've written is wrong ,because r1 is undefined in the switch case. Is there any other correct way to achieve it.

asked Mar 29 '17 at 05:54

hrushilok

how are you defining r1? – meyer9 Mar 29 '17 at 05:55
hi @meyer9, const readline = require('readline'); and then I've written it in a code. – hrushilok Mar 29 '17 at 05:57
that's not r1. something like `var r1 = something` – meyer9 Mar 29 '17 at 05:58
I recommend you to read [this](http://stackoverflow.com/questions/8128578/reading-value-from-console-interactively). – MUT Mar 29 '17 at 05:59
Hi @MUT, But the problem prevails, coz any variable declared outside is undefined in the switch case statement. – hrushilok Mar 29 '17 at 06:07
@MUT it has worked... thank you... – hrushilok Apr 10 '17 at 14:46

how can we write a perfect menu driven program using switch case in node js

0 Answers0