Storing nodejs fs.readfile's result in a variable and pass to global variable

Question

I\'m wondering if it\'s possible to pass the contents of fs.readfile out of the scope of the readfile method and store it in a variable similar to.

var a;

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Answer 1

The problem you have isn't a problem of scope but of order of operations.

As readFile is asynchronous, console.log(global_data); occurs before the reading, and before the global_data = data; line is executed.

The right way is this :

fs.readFile("example.txt", "UTF8", function(err, data) {
    if (err) { throw err };
    global_data = data;
    console.log(global_data);
});

In a simple program (usually not a web server), you might also want to use the synchronous operation readFileSync but it's generally preferable not to stop the execution.

Using readFileSync, you would do

var global_data = fs.readFileSync("example.txt").toString();