JSON output not showed correctly , javascript

Question

I create class in javascript to output config.json

const fs = require('fs');

class config {
    static put(input1,input2) {
        let json = {
            input1 , input2 }
        json = JSON.stringify(json);
        fs.writeFile('./config.json', json, (err) => {
            if (!err) {
                console.log('done');
            }
        });
    }
}

config.put('site_name', 'Blog');       
config.put('maintenance', false);   
config.put('age', 30);                  
config.put('meta', {"description": "lorem ipsum"});

will output config.json like this

{"input1":"meta","input2":{"description":"lorem ipsum"}}

i expect to output config.json

{ input1: 'site_name', input2: 'Blog' }
{ input1: 'maintenance', input2: false }
{ input1: 'age', input2: 30 }
{ input1: 'meta', input2: { description: 'lorem ipsum' } }

aren't you overwriting the file each time instead of appending into it? — zedling, May 29 '18 at 07:31
Possible duplicate of [How to append to a file in Node?](https://stackoverflow.com/questions/3459476/how-to-append-to-a-file-in-node) — Nikhil Aggarwal, May 29 '18 at 07:34
Why do you call the file config.json when you don't store JSON in it? — str, May 29 '18 at 07:35

score 1 · Accepted Answer · answered May 29 '18 at 07:33

Use append instead of write

const fs = require('fs');

class config {
    static put(input1,input2) {
        let json = { input1 , input2 };

        json = JSON.stringify(json);

        fs.appendFile('./config.json', json, (err) => {
            if (!err) {
                console.log('done');
            }
        });
    }
}

score 0 · Answer 2 · answered May 29 '18 at 07:37

Default options flag for writeFile is 'w' which will overwrite, you will need to specify 'a' for appending.

See here: https://nodejs.org/api/fs.html#fs_fs_writefile_file_data_options_callback and here for the file system flags: https://nodejs.org/api/fs.html#fs_file_system_flags

JSON output not showed correctly , javascript

2 Answers2