javascript let not working in various browsers

Question

let doesnt't work in some browsers. Not in their interpeters/ web consoles either. Why?

(originally I thought there was an inconsistency b/t the browser interpeter and the jsFiddle, but it turns out not to be true, just bad tests on my part.)

If your bowser doesn't support it, it won't work in JSFiddle either. Can you a link a fiddle where it does "work"? — Alex Wayne, Apr 30 '12 at 18:18
@EliranMalka: https://developer.mozilla.org/en/New_in_JavaScript_1.7#let_statement — Evert, Apr 30 '12 at 18:21
seriously when will they stop adding useless features to javascript — mihai, Apr 30 '12 at 18:24
@Mathletics: How 'bout these: https://developer.mozilla.org/en/JavaScript/Reference/Scope_Cheatsheet , specifically the for heads part? — user420667, Apr 30 '12 at 18:29

score 5 · Answer 1 · answered Apr 30 '12 at 18:25

5

In order to use some of the new features of JavaScript 1.7, you need to specify that you wish to use JavaScript 1.7. In HTML or XUL code, use

<script type="application/javascript;version=1.7"/>

answered Apr 30 '12 at 18:25

suhair

10,895
11
52
63

score 3 · Accepted Answer · edited Apr 30 '12 at 18:22

3

It is a non-standard keyword introduced in JS 1.7, not necessarily implemented in different browsers.

https://developer.mozilla.org/en/JavaScript/Reference/Statements/let

edited Apr 30 '12 at 18:22

Evert

93,428
18
118
189

answered Apr 30 '12 at 18:19

Evan Davis

35,493
6
50
57

2

Only implemented in Gecko, from what I understand. What Mozilla calls 'Javascript 1.7' has nothing to do with 'Ecmascript' which is what everybody implements. – Evert Apr 30 '12 at 18:22

javascript let not working in various browsers

2 Answers2

Linked