Constantly push into array in Javascript

Question

I currently have a function in my javascript in which I am trying to constantly push elements into an array. It looks something like this:

setInterval(function () {
    var currentdate = new Date(); 
    var datetime = currentdate.getFullYear() + "-" +
                   (currentdate.getMonth() + 1) + "-" +
                   currentdate.getDate();

    var arrayofdates = [];
    arrayofdates.push(datetime);
    document.getElementById("demo").innerHTML = arrayofdates;

    var a = (Math.random() * 100) + 1;
    var b = (Math.random() * 100) + 1;
    var c = (Math.random() * 100) + 1;

    chart.load({
        columns: [
            ['x', datetime],
            ['data1', a],
            ['data2', b],
            ['data3', c]
        ]
    });
}, 1000);

For some reason, the arrayofdates is only stuck in one. I have checked the properties of the arraylist and even if the string is already in the list, it should still add onto the list. In this case, I am getting a string similar to 2015-08-11, but I expect the arraylist to keep on adding 2015-08-11 after every second. What am I doing wrong?? Thanks!

That keeps happening because you keep re-declare your array every single time. — André Silva
– André Silva, Commented Aug 12, 2015 at 1:03
@Isuckatprogramming—you mean re–initialising every time. ;-) — RobG
– RobG, Commented Aug 12, 2015 at 1:19

Peter Peng · Accepted Answer · 2015-08-12 01:02:38Z

4

Your 'var arrayofdates' variable is re-created each time when the setInterval callback fires. Try declare it outside the setInterval()

answered Aug 12, 2015 at 1:02

Peter Peng

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1 Comment

user2677095 Over a year ago

Can't believe I missed that. One of the dumbest errors I've made! Thanks a lot!

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