How do I read a JSON file, change some values, and save it. Using FS/Javascript

Question

My current code is below.

bot.on('message', mssg => {
    io.emit('chat message', `${mssg.author.tag} - ${mssg.content}`);
    
    var message = mssg.content.toLowerCase()
    if(shydudearray.includes(message)) {
        var newMsg = message.replace(" ", "");
        fs.readFile('./assets/data/shydude.json', (err, data) => {
            if (err) throw err;
            let counter = JSON.parse(data);
            
            x = counter[newMsg];
            data[newMsg] = '2';
            
            console.log(`Before: ${x}\nAfter: ${counter[newMsg]}`)
        });
    }
});

I want to grab my JSON file and get the current number, then +1 to the current number, and save it to the JSON file. Using FS/Javascript, how could I get this to work?

Are you seeing any errors? What's wrong with the current code? — evolutionxbox, May 05 '21 at 14:48
There are no errors. What's wrong with my current code is that it's not saving to my JSON file in./assets/data/shydude.json. — Godz, May 05 '21 at 14:53
You have to convert the data back to JSON and write it to disk. — Felix Kling, May 05 '21 at 14:54
I'm a little confused. Changing a variable in JS will not affect a file. Are you expecting it to? — evolutionxbox, May 05 '21 at 14:55
I want to grab my JSON file and get the current number, then +1 to the current number, and save it to the JSON file. @evolutionxbox — Godz, May 05 '21 at 14:56

score 1 · Accepted Answer · edited May 05 '21 at 15:05

1

Here

const fs = require('fs');
const filepath = './myJSONfile.json';
const data = JSON.parse(fs.readFileSync(filepath));
data[someKey] = "newValue";
fs.writeFileSync(filepath, JSON.stringify(data, null, 4));

PS: This is a NodeJS question more than JavaScript

Edit From Question Asker: Fixed Variable Mistake

edited May 05 '21 at 15:05

Godz

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answered May 05 '21 at 14:54

savageGoat

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Wow, thank you so much. I would have been searching for ages. Works perfectly. – Godz May 05 '21 at 15:01

How do I read a JSON file, change some values, and save it. Using FS/Javascript

1 Answers1