node js write read string to file

// basic read-write string from-to file with node.js 
var fs = require('fs');
var opath = 'test.txt'; 
var ostring = 'Hello!'
fs.writeFileSync(opath, ostring, 'utf8');
var istring = fs.readFileSync('test.txt').toString();
console.log(istring);

// with error handling and logging:  
fs.readFile('test.txt', 'utf8' , (err, data) => {
    if (err) {
        console.error(err)
        return
    }
    console.log(data)
  });

// or fs.readFileSync() or use streams for large files
// for better memory consumption and execution speed
// https://nodejs.dev/learn/reading-files-with-nodejs