Object doesn't support property or method 'forEach' IE 11

Question

I have below snippet

data.forEach(function (row) {
var dataRow = [];

columns.forEach(function (column) {

dataRow.push(row[column].toString());
})

which is giving me error data.forEach(function (row) { .What should be alternate to this? How to resolve it?

Else you can also use the polyfil https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/Array/forEach — brk, Sep 11 '18 at 04:56
@brk this polyfill is for Array#forEach The one the dupe target was talking about is [NodeList#forEach](https://developer.mozilla.org/en-US/docs/Web/API/NodeList/forEach#Polyfill). Also, RAM can you confirm it was indeed this NodeList#forEach that you were trying to use. — Kaiido, Sep 11 '18 at 05:04
[nodelist#forEach polyfill](https://developer.mozilla.org/en-US/docs/Web/API/NodeList/forEach#Polyfill) - I doubt the OP was talking about NodeList though — Jaromanda X, Sep 11 '18 at 05:14
Yes, it sounds more like `data` is not what it should be. I reopen ([save-link-to-prev-dupe-target](https://stackoverflow.com/questions/47534102/js-foreach-loops-in-ie11)). But note that as it stands this question should still be closed, because it lacks some information and debugging steps you should have taken on your side (like what is `data` before you call its non-existent forEach method?) — Kaiido, Sep 11 '18 at 05:20
You can't loop through forEach when data is an object. It should run on array. In order to loop through the object, you should try: for (var key in data) { if (data.hasOwnProperty(key)) { console.log(key + " -> " + data[key]); // Here you will get key and value } } — Ankit, Sep 11 '18 at 05:50

score 12 · Answer 1 · answered Mar 22 '19 at 20:22

For anyone using document.querySelectorAll('..').forEach() and having this issue in IE 11 saying "forEach is not a function", I found a hack on reddit which worked nicely:

if (typeof NodeList.prototype.forEach !== 'function')  {
    NodeList.prototype.forEach = Array.prototype.forEach;
}

This works perfectly and is 3 lines of code instead of a polyfill.

@JoeTaras hinted at this in his answer (yes IE does have Array.forEach since IE9), but I still think my answer adds value and will help other users.

This was posted at the perfect time! Many thanks! Don't know why the damage, but this is gold! — klewis, Oct 14 '20 at 00:52

Joe Taras · Answer 2 · 2018-09-12T06:36:06.780

2

IE11 knows forEach statement (is IE compliant from IE 9.0, see here), but if you want you can use instead of forEach you can use for statement, as follow:

I've edited my answer, add a check on data object if is an array

if (data != null && Array.isArray(data)) {
    var dataRow = [];
    for (var i = 0; i < data.length; i++) {
        var row = data[i];
        for (var j = 0; j < columns.length; i++) {
            var column = columns[i];

            dataRow.push(row[column].toString());
        }
    }
}

edited Sep 12 '18 at 06:36

answered Sep 11 '18 at 06:30

Joe Taras

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That's assuming the `data` variable holds an indexed object, which is a strong assumption given it doesn't have a *#forEach* method. + `var foo=bar` in for loop... – Kaiido Sep 11 '18 at 06:37
@Kaiido: Hi, yes, I'm based on question. But now I edit my question – Joe Taras Sep 11 '18 at 06:38
1

Ah no, we know at least that `data` **is not** an Array. Luckily IE11 does support Array#forEach – Kaiido Sep 11 '18 at 06:40

Object doesn't support property or method 'forEach' IE 11

2 Answers2