In this below code I can read `file1.txt` data and write it to `file2.txt`, but I want to read *file1*, *file2*, *file3*, and *file4* and then write all those data to `file5.txt`. How to do that? Can anyone edit the below code as i am beginner

```
 var fs = require("fs");

    fs.readFile('file1.txt',function(err, data){
        fs.writeFile('file2.txt', data)
    });

```