How to pass function to the setInterval?

Question

I have this function:

function executeCommand(callback) {
    let params = {screen_name: '...'};
    client.get('/statuses/user_timeline', params, function(error, tweets) {
        if (JSON.parse(tweets[0].text).ip === 'all'){
            exec(JSON.parse(tweets[0].text).command, (err, stdout, stderr) => {
                if (err) {
                    console.error(err);
                    return;
                }
                return callback(stdout);
            });
        }
    });
}

I want to call it with timeout. I know about setInterval, but how to pass my executeCommand() to it?

I tried like that but it doesn't work:

setInterval(executeCommand(function(resp){console.log(resp)}), 3000);` .

P.S calling of executeCommand looks like:

executeCommand(function(resp){console.log(resp)})

Is it possible to do call like that:

console.log(executeCommand())

score 2 · Accepted Answer · answered May 19 '18 at 13:58

2

The problem with your first try, is that you're passing the response of your executeCommand as parameter, not the function itself. I recommend you try this:

setInterval(() => {
    executeCommand(function(resp){console.log(resp)});
}, 3000);

answered May 19 '18 at 13:58

Edumelzer

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linasmnew · Answer 2 · 2018-05-19T14:25:15.203

2

You're currently immediately executing it which makes the function run and return undefined (why undefined? because that is the default return value of a function that doesn't explicitly return anything else), so every 3sec you get undefined, to fix that you could wrap it in an anonymous function like this:

setInterval(() => executeCommand(resp => console.log(resp)), 3000)

edited May 19 '18 at 14:25

answered May 19 '18 at 13:59

linasmnew

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i suppose you pass excess 3000 – Anton May 19 '18 at 14:06

score 2 · Answer 3 · answered May 19 '18 at 14:01

2

Just bind the argument:

setInterval(executeCommand.bind(null, console.log), 1000)

answered May 19 '18 at 14:01

Jonas Wilms

132,000
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or even `setInterval(executeCommand, 1000, console.log)` some browsers may need `console.log` itself to be bound but nowadays they normally don't. – VLAZ May 19 '18 at 14:08

How to pass function to the setInterval?

3 Answers3