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#7260 closed bug (invalid)
Opened October 20, 2010 08:02PM UTC
Closed October 20, 2010 09:32PM UTC
Last modified July 24, 2012 01:09AM UTC
$.each() fails on an object when the object has a key named 'length'
| Reported by: | lucas.madar@gmail.com | Owned by: | |
|---|---|---|---|
| Priority: | undecided | Milestone: | 1.5 |
| Component: | unfiled | Version: | 1.4.2 |
| Keywords: | Cc: | ||
| Blocked by: | Blocking: |
Description
If you have an object, like this:
var obj = { name: "something", length: 12, height: 32 };
and then you try to iterate over it using $.each:
$.each( obj, function( key, value ) {
...
} );
The inner function is never called because jquery treats the object as an array instead of an object. This behavior is unexpected; it should either be documented or fixed.
Attachments (0)
Change History (9)
Changed October 20, 2010 09:23PM UTC by comment:1
| _comment0: | I think you misread the documentation. `$.each` behaves exactly as expected and as documented. \ \ From http://api.jquery.com/jQuery.each/ \ >Arrays and **array-like objects with a length property** (such as a function's arguments object) are iterated by numeric index, from 0 to length-1. Other objects are iterated via their named properties. \ \ This sentence covers your case, stating that objects with a length property (as in your example) are iterated by numeric index. \ \ So if you remove/name the length property in your sample object `$.each` while behave as expected. \ \ Here a [http://www.jsfiddle.net/jitter/qvWAQ/ live test case] to show what is happening. → 1287609930874185 |
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Changed October 20, 2010 09:32PM UTC by comment:2
| resolution: | → invalid |
|---|---|
| status: | new → closed |
Changed March 06, 2011 12:17AM UTC by comment:3
I fail to see how a json object with a quoted length property could be considered an array-like object.
Changed March 31, 2011 02:37PM UTC by comment:4
This is also a problem in jQuery templates when using {{each}} to iterate through an object which happens to have a "length" key.
Changed April 16, 2011 06:35PM UTC by comment:5
| _comment0: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now:''' \ isObj = length === undefined || jQuery.isFunction( object ); \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ This would allow looping over objects with length props. I'm not sure the speed implications, that would have to be tested. \ → 1302979008229212 |
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| _comment1: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now being used in jQuery.each (object/array detection):''' \ \ {{{ \ isObj = length === undefined || jQuery.isFunction( object ); \ }}} \ \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ \ {{{ \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ }}} \ \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ This would allow looping over objects with length props. I'm not sure the speed implications, that would have to be tested. \ → 1302979914983617 |
| _comment2: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now being used in jQuery.each (object/array detection):''' \ \ {{{ \ isObj = length === undefined || jQuery.isFunction( object ); \ }}} \ \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ \ {{{ \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ }}} \ \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ Here's a fiddle with me changing that one line: http://jsfiddle.net/jboesch26/Ungsa/ \ \ This would allow looping over objects with length props. I'm not sure the speed implications, that would have to be tested. \ → 1302982098738507 |
| _comment3: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now being used in jQuery.each (object/array detection):''' \ \ {{{ \ isObj = length === undefined || jQuery.isFunction( object ); \ }}} \ \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ \ {{{ \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ }}} \ \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ Here's a fiddle with me changing that one line: http://jsfiddle.net/jboesch26/Ungsa/ \ \ This would allow looping over objects with length props. This newEach proposal seems to be slightly faster as well: http://jsperf.com/each-object-supporting-length-key \ → 1302982139150960 |
| _comment4: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now being used in jQuery.each (object/array detection):''' \ \ {{{ \ isObj = length === undefined || jQuery.isFunction( object ); \ }}} \ \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ \ {{{ \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ }}} \ \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ Here's a fiddle with me changing that one line: http://jsfiddle.net/jboesch26/Ungsa/ \ \ This would allow looping over objects with length props. This newEach proposal seems to be slightly faster as well: http://jsperf.com/each-object-supporting-length-key \ \ If this is cool, I'll make a pull request. \ → 1303088355745872 |
| _comment5: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now being used in jQuery.each (object/array detection):''' \ \ {{{ \ isObj = length === undefined || jQuery.isFunction( object ); \ }}} \ \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ \ {{{ \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ }}} \ \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ Here's a fiddle with me changing that one line: http://jsfiddle.net/jboesch26/Ungsa/ \ \ This would allow looping over objects with length props. This newEach proposal seems to be slightly faster as well: http://jsperf.com/each-object-supporting-length-key/4 \ \ If this is cool, I'll make a pull request. \ → 1303155014015869 |
| _comment6: | I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here. \ \ '''Here is what the code is right now being used in jQuery.each (object/array detection):''' \ \ {{{ \ isObj = length === undefined || jQuery.isFunction( object ); \ }}} \ \ \ '''This can be changed to what's being used in jQuery.map (v 1.6):''' \ \ {{{ \ isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ; \ }}} \ \ \ Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files \ \ Here's a fiddle with me changing that one line: http://jsfiddle.net/jboesch26/Ungsa/ \ \ This would allow looping over objects with length props. This newEach proposal seems to be slightly faster as well: http://jsperf.com/each-object-supporting-length-key/6 \ \ If this is cool, I'll make a pull request. \ → 1303155026828096 |
I think we can fix this issue. If jQuery.map is supporting objects in 1.6 (and works with length props) I think we should maybe consider adding it here.
Here is what the code is right now being used in jQuery.each (object/array detection):
isObj = length === undefined || jQuery.isFunction( object );
'''This can be changed to what's being used in jQuery.map (v 1.6):'''
isArray = elems instanceof jQuery || length !== undefined && typeof length === "number" && ( ( length > 0 && elems[ 0 ] && elems[ length -1 ] ) || jQuery.isArray( elems ) ) ;
Here's Dan's isArray var in action in the jQuery.map function: https://github.com/jquery/jquery/pull/299/files
Here's a fiddle with me changing that one line: http://jsfiddle.net/jboesch26/Ungsa/
This would allow looping over objects with length props. This newEach2 proposal seems to be slightly faster as well: http://jsperf.com/each-object-supporting-length-key/6
If this is cool, I'll make a pull request.
Changed April 18, 2011 05:20AM UTC by comment:6
| _comment0: | I've committed a patch, but I'm gonna finish testing in IE before making a pull request: \ https://github.com/jboesch/jquery/commit/507e48c040cd5aaf70a50d402d5f91fc07f0ea7b → 1303182363336430 |
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| _comment1: | Pull requested: https://github.com/jquery/jquery/pull/336/files → 1303182373397782 |
Pull request: https://github.com/jquery/jquery/pull/336/files
This exact behavior is well documented thus
$.eachbehaves exactly as expected.From http://api.jquery.com/jQuery.each/
>Arrays and **array-like objects with a length property** (such as a function's arguments object) are iterated by numeric index, from 0 to length-1. Other objects are iterated via their named properties.
Here a live test case to show what is happening.