CODEWITHSUNDEEP
javascriptphparraysjsonajax
Ben
Ben

Reputation: 1914

How to empty an array?

Yesterday I ask a question about json

Link: How to return an array from jQuery ajax success function and use it in a loop?

And one of the answers was this

setInterval(updateTimestamps,30000);
var ids = new Array();

function updateTimestamps(){
    $(".timestamp").each(function(i){
    var obj = new Object();
    obj.id = $(this).attr("postID");
    obj.timestamp = $(this).attr("postdate");
        ids.push(obj);
    }

    $.post("http://site.com/ajax/humanTime.php", {"time": ids}, function(data) {
        for (i = 0; i < data.length; i++) {
            $("#" + data[i].id).html(data[i].content);
        }
    }, "json");
}

The problem with this script is that the data is dublicated

The first time when this is executed is something like this

Array
(
    [0] => Array
        (
            [id] => 26629
            [timestamp] => 1332273712
        )

    [1] => Array
        (
            [id] => 26628
            [timestamp] => 1332243526
        )

    [2] => Array
        (
            [id] => 26627
            [timestamp] => 1332237777


)

And the second time is

Array
(
    [0] => Array
        (
            [id] => 26629
            [timestamp] => 1332273712
        )

    [1] => Array
        (
            [id] => 26628
            [timestamp] => 1332243526
        )

    [2] => Array
        (
            [id] => 26627
            [timestamp] => 1332237777
        )

    [3] => Array
        (
            [id] => 26629
            [timestamp] => 1332273712
        )

    [4] => Array
        (
            [id] => 26628
            [timestamp] => 1332243526
        )

    [5] => Array
        (
            [id] => 26627
            [timestamp] => 1332237777
        )

)

I try with var ids= Array(); , vas ids = []; but that dosent work

Upvotes: 1

Views: 120

Answers (5)

Salman Arshad
Salman Arshad

Reputation: 272106

Set ids = [] before you start pushing new items. Here is your code, re-factored:

var ids;

function updateTimestamps() {
    ids = []; // <-- the answer
    $(".timestamp").each(function(i) {
        ids.push({
            id: $(this).attr("postID"),
            timestamp: $(this).attr("postdate")
        });
    });
    $.post("http://site.com/ajax/humanTime.php", {"time": ids}, function(data) {
        for (var i = 0; i < data.length; i++) {
            $("#" + data[i].id).html(data[i].content);
        }
    }, "json");
}

setInterval(updateTimestamps, 30000);​

Upvotes: 3

KooiInc
KooiInc

Reputation: 122906

A short way to reset an array: ids.length = 0;. So

function updateTimestamps(){
  ids.length = 0;
  // [...]
}

Upvotes: 3

xdazz
xdazz

Reputation: 160833

setInterval(updateTimestamps,30000);

function updateTimestamps(){
    var ids = []; // put it here

    $(".timestamp").each(function(i){
    var obj = {};
    obj.id = $(this).attr("postID");
    obj.timestamp = $(this).attr("postdate");
        ids.push(obj);
    }

    $.post("http://site.com/ajax/humanTime.php", {"time": ids}, function(data) {
        for (i = 0; i < data.length; i++) {
            $("#" + data[i].id).html(data[i].content);
        }
    }, "json");
}

Upvotes: 2

Dogbert
Dogbert

Reputation: 222128

After

function updateTimestamps(){

Add

ids = [];

Upvotes: 2

Fabrizio Calderan
Fabrizio Calderan

Reputation: 123377

try this:

var ids;

function updateTimestamps(){
  ids = [];
   ...

Upvotes: 2

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