CODEWITHSUNDEEP
javascriptnode.js
user1700840
user1700840

Reputation: 451

How to alter a global variable from a function called when an event triggers?

Using NodeJS and node-csv, I'm trying to load rows in a Array. From an example in the module:

// node samples/string.js
csv()
    .from.string(
        '#Welcome\n"1","2","3","4"\n"a","b","c","d"', {
            comment: '#'
        })
    .to.array(function (data) {
        console.log(data)
    });
// [ [ '1', '2', '3', '4' ], [ 'a', 'b', 'c', 'd' ] ]

But if inside function (data) I try to add each row to an Array defined in the global scope, it doesn't alter it. It's obvious I don't understand JS variables scope, but what's the best pattern to solve this problem?

Upvotes: 0

Views: 55

Answers (1)

Sherlock
Sherlock

Reputation: 5627

It looks like it is altering the rows variable, but the console.log() call is being called before the rows are pushed. You can use the .on('end') event to call a function after they have been pushed.

var csv = require('csv');
var rows = new Array();


csv()
    .from.string(
        '#Welcome\n"1","2","3","4"\n"a","b","c","d"', {
            comment: '#'
        })
    .to.array(function (data) {
    rows.push(data);
        console.log(rows);
    }).on('end', function() {
        logRows();
    });

var logRows = function() {
    console.log(rows);
}

Upvotes: 1

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