node - execution context of callback function

Asked Dec 07 '16 at 16:18

Active Dec 07 '16 at 16:20

Viewed 12 times

Hi i'm getting confused about the following execution context

let fs = require('fs');
let text;

fs.readFile('message.txt', 'utf8', function(err, contents) {
    text = contents;
}
console.log(text)

text is undefined outside the callback function..thanks!

edited Dec 07 '16 at 16:20

asked Dec 07 '16 at 16:18

Han Che

i want to use text outside of the callback and store it in text globally – Han Che Dec 07 '16 at 16:20
Understood, but that's not really how async functionality works. – Dave Newton Dec 07 '16 at 16:22
ah the fs.readFile is async? ok that explains it :D – Han Che Dec 07 '16 at 16:22
Precisely as the docs state: "Asynchronously reads the entire contents of a file." If it wasn't, why would you need a callback function to do something with the contents? – Dave Newton Dec 07 '16 at 16:23

0 Answers0