[`parseInt`][1] receives two arguments: string and radix:

&gt; `var intValue = parseInt(string[, radix]);`

while [`map`][2] handler&#39;s second argument is index:

&gt; ... callback is invoked with three arguments: the value of the element,
&gt; the index of the element, and the Array object being traversed.



  [1]: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/parseInt
  [2]: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/Array/map

`parseInt` uses the first two arguments being passed in by map, and uses the second argument to specify the radix.

Here&#39;s what&#39;s happening in your code:

    parseInt(&#39;10&#39;, 0) // 10
    parseInt(&#39;10&#39;, 1) // NaN
    parseInt(&#39;10&#39;, 2) // 2
    parseInt(&#39;10&#39;, 3) // 3
    parseInt(&#39;10&#39;, 4) // 4

Here&#39;s a link to MDN on `parseInt`: https://developer.mozilla.org/en-US/docs/JavaScript/Reference/Global_Objects/parseInt.

From MDN:

&gt; callback is invoked with three arguments: the value of the element,
&gt; the index of the element, and the Array object being traversed.

`parseInt()` takes two arguments. The value and the radix. That means that the `parseInt()` function is being called with unintended parameters.

I have a html page where I am appending html at dynamically through a javascript like below

    &lt;script type=&quot;text/javascript&quot; src=&quot;/myapp/htmlCode&quot;&gt;&lt;/script&gt;

I want to call a js function e.g. loadedContent(); once the above script adds dynamic html.

Can someone help me how I can do that?

Call javascript function after script is loaded

I have an input defined as

    &lt;input class=&quot;datepicker&quot; type=&quot;text&quot; ng-model=&quot;clientForm.birthDate&quot; /&gt;

Which is rigged up to be displayed elsewhere on the page:

    &lt;tr&gt;
        &lt;th&gt;Birth Date&lt;/th&gt;
        &lt;td&gt;{{client.birthDate|date:&#39;mediumDate&#39;}}&lt;/td&gt;
    &lt;/tr&gt;

When the page loads the birth date is nicely formatted as something like `Dec 22, 2009`. However, when I look inside my `&lt;input&gt;` it&#39;s shown as `Tue Dec 22 2009 00:00:00 GMT-0800 (Pacific Standard Time)` which I guess is how JS renders `Date` objects as strings.

Firstly, how do I tell Angular to show the date in the `&lt;input&gt;` as something like `12/22/2009`? I can&#39;t seem to apply `|filters` inside the `ng-model` attribute.

Secondly, as soon as I edit the date, even keeping it in it&#39;s original format, my other text (inside the `&lt;td&gt;`) doesn&#39;t seem to apply the `|date` filter anymore; it suddenly changes formats to match that of the input textbox. How do I get it to apply the `|date` filter every time the model changes?

---

Related questions:

- https://stackoverflow.com/q/14494026/65387
- https://stackoverflow.com/q/14494095/65387

How to format a date using ng-model?

&gt; **Possible Duplicate:**  
&gt; [javascript - Array.map and parseInt](https://stackoverflow.com/questions/262427/javascript-array-map-and-parseint)  

&lt;!-- End of automatically inserted text --&gt;

I saw this example of strange JavaScript behavior [on twitter](https://twitter.com/garybernhardt/status/294874591120211968)

    [&#39;10&#39;,&#39;10&#39;,&#39;10&#39;,&#39;10&#39;,&#39;10&#39;].map(parseInt)

evaluates to

    [10, NaN, 2, 3, 4]

could somebody explain this behavior?  I verified it in chrome and firebug


    [&#39;10&#39;,&#39;10&#39;,&#39;10&#39;,&#39;10&#39;,&#39;10&#39;].map(function(x){return parseInt(x);})

correctly returns an array of 10s as integers.  Is this an improper use of map(), a bug with parseInt, or something else?

Strange behavior for Map, parseInt

> Possible Duplicate: 
> <a href="https://stackoverflow.com/questions/262427/javascript-array-map-and-parseint" target="_blank" rel="noopener noreferrer">javascript - Array.map and parseInt</a>

I saw this example of strange JavaScript behavior <a href="https://twitter.com/garybernhardt/status/294874591120211968" target="_blank" rel="noopener noreferrer">on twitter</a>
<pre><code class="hljs language-scss">['10','10','10','10','10'].map(parseInt)
</code></pre>
evaluates to
<pre><code class="hljs language-csharp">[10, NaN, 2, 3, 4]
</code></pre>
could somebody explain this behavior? I verified it in chrome and firebug
<pre><code class="hljs language-javascript">['10','10','10','10','10'].map(function(x){return parseInt(x);})
</code></pre>
correctly returns an array of 10s as integers. Is this an improper use of map(), a bug with parseInt, or something else?

I have a model returning in the storeLocations object with a isDefault value. if isDefault returns true, I wan&#39;t to set that radio button in the group as checked.

Not sure if I need to do a $each(data, function(index,value) and iterate through each object returned or if there&#39;s an easier way to do this using angular constructs.

Object:

    storeLocations = [
     {
      ... more values,
      isDefault: true
     }
    ]


Markup:

        &lt;tr ng-repeat=&quot;location in merchant.storeLocations&quot;&gt;
        	&lt;td&gt;{{location.name}}&lt;/td&gt;
        	&lt;td&gt;{{location.address.address1}}&lt;/td&gt;
        	&lt;td&gt;{{location.address.address2}}&lt;/td&gt;
        	&lt;td&gt;{{location.address.city}}&lt;/td&gt;
        	&lt;td&gt;{{location.address.stateProvince}}&lt;/td&gt;
        	&lt;td&gt;{{location.address.postalCode}}&lt;/td&gt;
        	&lt;td&gt;{{location.address.country}}&lt;/td&gt;
        	&lt;td&gt;{{location.website}}&lt;/td&gt;
        	&lt;td&gt;{{location.zone}}&lt;/td&gt;
        	&lt;td&gt;&lt;input type=&quot;radio&quot; ng-model=&quot;location.isDefault&quot; value=&quot;{{location.isDefault}}&quot; name=&quot;isDefault_group&quot;&gt;&lt;/td&gt;



AngularJs: How to set radio button checked based on model

I am trying to save a data object in chrome sync storage and then retrieve it, however the get() function always returns an empty object. The code I am using is,

    function storeUserPrefs() {
    	var key=&#39;myKey&#39;, testPrefs = {&#39;val&#39;: 10};
            chrome.storage.sync.set({key: testPrefs}, function() {console.log(&#39;Saved&#39;, key, testPrefs);});
    }

    function getUserPrefs() {
   		chrome.storage.sync.get(&#39;myKey&#39;, function (obj) {
   			console.log(&#39;myKey&#39;, obj);
   		});
    }

Could someone please tell me what I am doing wrong here?

saving and retrieving from chrome.storage.sync

While JavaScript&#39;s type-strict comparison operators (`===`, `!==`) are nice, it doesn&#39;t have corresponding strict comparisons for greater/less than.

    var x = 10;

    x &lt;= 20;    // true
    x &lt;= &#39;20&#39;;    // true
    x &lt;== 20;   // true (or would be, if JS had such an operator)
    x &lt;== &#39;20&#39;; // false (ditto)

Why not?  I ask this question fully expecting the answer to be &quot;uh, because it doesn&#39;t&quot;, but I&#39;m asking anyway, in case there&#39;s an interesting and/or disheartening historical reason for such operators being omitted.

Why doesn&#39;t JavaScript have strict greater/less than comparison operators?

Is there an `addEventListener` for the &lt;kbd&gt;Enter&lt;/kbd&gt; key?

I have

    document.querySelector(&#39;#txtSearch&#39;).addEventListener(&#39;click&#39;, search_merchants);

I know this is intended for `&lt;button&gt;`, but wanted to know if there&#39;s an equivalent for catching the &lt;kbd&gt;Enter&lt;/kbd&gt; key.

EventListener Enter Key

Recently I have been working with the Chrome Plugin API and I am looking to develop a plugin which will make life easier for me for managing a website.

Now what I wish to do is to fire an event when a certain checkbox is checked.
As this website does not belong to me I cannot change the code therefore I am using the Chrome API. One of the main problems is that rather than there being an ID, there is a Name. I was wondering if I could fire the function once the certain checkbox with the &#39;name&#39; is checked.




Checkbox Check Event Listener

I want to have a binary operator `cross` (cross-product/cartesian product) that operates with traversables in Scala:

    val x = Seq(1, 2)
    val y = List(&#39;hello&#39;, &#39;world&#39;, &#39;bye&#39;)
    val z = x cross y    # i can chain as many traversables e.g. x cross y cross w etc
    
    assert z == ((1, &#39;hello&#39;), (1, &#39;world&#39;), (1, &#39;bye&#39;), (2, &#39;hello&#39;), (2, &#39;world&#39;), (2, &#39;bye&#39;))

What is the best way to do this in Scala only (i.e. not using something like scalaz)?

Cross product in Scala

I have an object:

    myObject = { &#39;a&#39;: 1, &#39;b&#39;: 2, &#39;c&#39;: 3 }

I am looking for a native method, similar to `Array.prototype.map` that would be used as follows:

    newObject = myObject.map(function (value, label) {
        return value * value;
    });
    
    // newObject is now { &#39;a&#39;: 1, &#39;b&#39;: 4, &#39;c&#39;: 9 }

Does JavaScript have such a `map` function for objects? (I want this for Node.JS, so I don&#39;t care about cross-browser issues.)

map function for objects (instead of arrays)

I am not able to get my head on how the partial works in functools.
I have the following code from [here](https://stackoverflow.com/questions/3252228/python-why-is-functools-partial-necessary):

    &gt;&gt;&gt; sum = lambda x, y : x + y
    &gt;&gt;&gt; sum(1, 2)
    3
    &gt;&gt;&gt; incr = lambda y : sum(1, y)
    &gt;&gt;&gt; incr(2)
    3
    &gt;&gt;&gt; def sum2(x, y):
        return x + y
    
    &gt;&gt;&gt; incr2 = functools.partial(sum2, 1)
    &gt;&gt;&gt; incr2(4)
    5

Now in the line

    incr = lambda y : sum(1, y)

I get that whatever argument I pass to `incr` it will be passed as `y` to `lambda` which will return `sum(1, y)` i.e `1 + y`.

I understand that. But I didn&#39;t understand this `incr2(4)`.

How does the `4` gets passed as `x` in partial function? To me, `4` should replace the `sum2`. What is the relation between `x` and `4`?



How does functools partial do what it does?

Assuming that I have a list with a huge number of items,

    l = [ 1, 4, 6, 30, 2, ... ]

I want to get the number of items from that list, where an item satisfies a certain condition. My first thought was:

    count = len([i for i in l if my_condition(l)])

But if the filtered list also has a great number of items, I think that
creating a new list for the filtered result is just a waste of memory.  For efficiency, IMHO, the above call can&#39;t be better than:

    count = 0
    for i in l:
        if my_condition(l):
            count += 1

Is there any functional-style way to get the # of items that satisfy the condition without generating a temporary list?

Get number of items from list (or other iterable) with certain condition

Suppose you&#39;re building a fairly large simulation in Haskell. There are many different types of entities whose attributes update as the simulation progresses. Let&#39;s say, for the sake of example, that your entities are called Monkeys, Elephants, Bears, etc..

What is your preferred method for maintaining these entities&#39; states?

The first and most obvious approach I thought of was this:

    mainLoop :: [Monkey] -&gt; [Elephant] -&gt; [Bear] -&gt; String
    mainLoop monkeys elephants bears =
      let monkeys&#39;   = updateMonkeys   monkeys
          elephants&#39; = updateElephants elephants
          bears&#39;     = updateBears     bears
      in
        if shouldExit monkeys elephants bears then &quot;Done&quot; else
          mainLoop monkeys&#39; elephants&#39; bears&#39;

It&#39;s already ugly having each type of entity explicitly mentioned in the `mainLoop` function signature. You can imagine how it would get absolutely awful if you had, say, 20 types of entities. (20 is not unreasonable for complex simulations.) So I think this is an unacceptable approach. But its saving grace is that functions like `updateMonkeys` are very explicit in what they do: They take a list of Monkeys and return a new one.

So then the next thought would be to roll everything into one big data structure that holds all state, thus cleaning up the signature of `mainLoop`:

    mainLoop :: GameState -&gt; String
    mainLoop gs0 =
      let gs1 = updateMonkeys   gs0
          gs2 = updateElephants gs1
          gs3 = updateBears     gs2
      in
        if shouldExit gs0 then &quot;Done&quot; else
          mainLoop gs3

Some would suggest that we wrap `GameState` up in a State Monad and call `updateMonkeys` etc. in a `do`. That&#39;s fine. Some would rather suggest we clean it up with function composition. Also fine, I think. (BTW, I&#39;m a novice with Haskell, so maybe I&#39;m wrong about some of this.)

But then the problem is, functions like `updateMonkeys` don&#39;t give you useful information from their type signature. You can&#39;t really be sure what they do. Sure, `updateMonkeys` is a descriptive name, but that&#39;s little consolation. When I pass in a [god object](http://en.wikipedia.org/wiki/God_object) and say &quot;please update my global state,&quot; I feel like we&#39;re back in the imperative world. It feels like global variables by another name: You have a function that does *something* to the global state, you call it, and you hope for the best. (I suppose you still avoid some concurrency problems that would be present with global variables in an imperative program. But meh, concurrency isn&#39;t nearly the only thing wrong with global variables.)

A further problem is this: Suppose the objects need to interact. For example, we have a function like this:

    stomp :: Elephant -&gt; Monkey -&gt; (Elephant, Monkey)
    stomp elephant monkey =
      (elongateEvilGrin elephant, decrementHealth monkey)

Say this gets called in `updateElephants`, because that&#39;s where we check to see if any of the elephants are in stomping range of any monkeys. How do you elegantly propagate the changes to both the monkeys and elephants in this scenario? In our second example, `updateElephants` takes and returns a god object, so it could effect both changes. But this just muddies the waters further and reinforces my point: With the god object, you&#39;re effectively just mutating global variables. And if you&#39;re not using the god object, I&#39;m not sure how you&#39;d propagate those types of changes.

What to do? Surely many programs need to manage complex state, so I&#39;m guessing there are some well-known approaches to this problem.

Just for the sake of comparison, here&#39;s how I might solve the problem in the OOP world. There would be `Monkey`, `Elephant`, etc. objects. I&#39;d probably have class methods to do lookups in the set of all live animals. Maybe you could lookup by location, by ID, whatever. Thanks to the data structures underlying the lookup functions, they&#39;d stay allocated on the heap. (I&#39;m assuming GC or reference counting.) Their member variables would get mutated all the time. Any method of any class would be able to mutate any live animal of any other class. E.g. an `Elephant` could have a `stomp` method that would decrement the health of a passed-in `Monkey` object, and there would be no need to pass that

Likewise, in an Erlang or other actor-oriented design, you could solve these problems fairly elegantly: Each actor maintains its own loop and thus its own state, so you never need a god object. And message passing allows one object&#39;s activities to trigger changes in other objects without passing a bunch of stuff all the way back up the call stack. Yet I have heard it said that actors in Haskell are frowned upon.

Content Type	Original Author	Original Content on Stackoverflow
Question	Ben McCormick	View Question on Stackoverflow
Solution 1 - Javascript	VisioN	View Answer on Stackoverflow
Solution 2 - Javascript	Joseph Silber	View Answer on Stackoverflow
Solution 3 - Javascript	Justin Niessner	View Answer on Stackoverflow

Strange behavior for Map, parseInt

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

How to format a date using ng-model?

Call javascript function after script is loaded

Attributions