javascript - Node.js console.log() in txt file

I have another question (last question). At the moment i am working on a Node.js project and in this I have many console.log() functions. This has worked okay so far but I also want everything that's written to the console to also be written in a log-file. Can someone please help me?

For example:

Console.log('The value of array position [5] is '+ array[5]);

In my real code its a bit more but this should give you an idea.

Thank you hopefully.

Answer

I would use a library instead of re-inventing the wheel. I looked for a log4j-type library on npm, and it came up with https://github.com/nomiddlename/log4js-node

if you want to log to the console and to a file:

var log4js = require('log4js');
log4js.configure({
  appenders: [
    { type: 'console' },
    { type: 'file', filename: 'logs/cheese.log', category: 'cheese' }
  ]
});

now your code can create a new logger with

var logger = log4js.getLogger('cheese'); 

and use the logger in your code

logger.warn('Cheese is quite smelly.');

logger.info('Cheese is Gouda.');
logger.debug('Cheese is not a food.');