[Start of Time][1] 
&lt;!-- language: lang-js --&gt;

    moment().startOf(&#39;day&#39;)


  [1]: http://momentjs.com/docs/#/manipulating/start-of/

Suppose **date** is the moment object which contains the date having some hours and minutes.

You can use the following code to reset hours, minutes and seconds to 0.
```
date.utcOffset(0);
date.set({
 hour: 0,
 minute: 0,
 second: 0,
 millisecond: 0,
});

to set second for example to &quot; 0 &quot;
`time = moment().second(0);`


If you want in string format, you can use like this: 
moment().format(&quot;YYYY-MM-DD 00:00:00&quot;)

I am Copying the same Question asked Before [Question][1].
I have tried the solutions given and was not able to solve it since **sizetofit** was not effective when I use Autolayout.

![first screenshot][2]

The expected display is like below.

![second screenshot][3]

  [1]: https://stackoverflow.com/questions/1054558/vertically-align-text-within-a-uilabel
  [2]: http://i.stack.imgur.com/656W8.jpg
  [3]: http://i.stack.imgur.com/RWPg7.png

Vertically align text within a UILabel (Note : Using AutoLayout)

I have a compile error involving a macro:

    &lt;mdo macros&gt;:6:19: 6:50 error: cannot move out of captured outer variable in an `FnMut` closure
    &lt;mdo macros&gt;:6 bind ( $ e , move | $ p | mdo ! { $ ( $ t ) * } ) ) ; (
                                     ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    &lt;mdo macros&gt;:1:1: 14:36 note: in expansion of mdo!
    &lt;mdo macros&gt;:6:27: 6:50 note: expansion site
    &lt;mdo macros&gt;:1:1: 14:36 note: in expansion of mdo!
    &lt;mdo macros&gt;:6:27: 6:50 note: expansion site
    &lt;mdo macros&gt;:1:1: 14:36 note: in expansion of mdo!
    src/parser.rs:30:42: 37:11 note: expansion site
    error: aborting due to previous error

Unfortunately, the macro is recursive so it&#39;s hard to figure out what the compiler is complaining about, plus it seems like the line numbers are for the expanded macro rather than my code.

How can I see the expanded macro? Is there a flag I can pass to rustc (or even better, cargo) to dump this out?

(This macro is from [rust-mdo](https://github.com/TeXitoi/rust-mdo), though I don&#39;t think it matters.)

How do I see the expanded macro code that&#39;s causing my compile error?

What is the easiest equivalent of `date.setHours(0,0,0,0)` when using moment.js?

Basically, if I need a `new Date()` moment with hours, minutes, seconds, and milliseconds zeroed out.

.setHours(0,0,0,0) with moment.js

<p>What is the easiest equivalent of <code>date.setHours(0,0,0,0)</code> when using moment.js?</p>
<p>Basically, if I need a <code>new Date()</code> moment with hours, minutes, seconds, and milliseconds zeroed out.</p>


I&#39;m extremely new to Gulp.  I&#39;m basically trying to watch for a modified JavaScript file, and then make a new copy of it with a new name.  (eventually there&#39;ll be some processing on it, but Rome wasn&#39;t built in a day).

My (naive) attempt is this:

    gulp.task(&#39;default&#39;, function() {
    
        return gulp.watch(&#39;../**/**.js&#39;, function(obj){
            gulp.src(obj.path)
                .pipe(gulp.dest(&#39;foobar.js&#39;));
        });
    
    });

This takes the modified file and successfully copies it into a folder now called foobar.js.  Is there anything simple I can replace `gulp.dest(&#39;foobar.js&#39;)` with that will simply copy and rename the src file in place?

---

EDIT

By copy in place, I mean I want to take the modified file, and make a copy of it right **where it currently is** with a new name.  The equivalent of clicking the file (in windows) and hitting control-c control-v, then renaming the resulting file.

Gulp - copy and rename a file

I&#39;m new to JavaScript ,to understand this concept i have read many articles regarding prototype and constructors but where ever i go i&#39;m left with confusion.

The confusion arises when people talk about constructor and prototype simultaneously.

In the following example 

    var employee = function Emp(name) {
        this.name = name;
    }
    var jack = new employee(&quot;Jack Dwain&quot;);
    
    employee.constructor //gives Function()
    
    employee.prototype // gives  Emp {}
    
    employee.prototype.constructor //gives Emp(name)
    
    jack.constructor //gives Emp(name)
    
    jack.prototype //gives undefined

1. prototype is a way JS achieves inheritance,since `Emp(name)` is the base function prototype is referenced to the same function itself. Is that what happened?


2. In what way `employee.constructor` and `employee.prototype.constructor` differ?

3. Why was `jack.prototype` is `undefined` i.e If it is inheriting from the function `Emp(name)` why it didn&#39;t reference that function?

4. How can I clearly predict  myself without typing in the console what the prototype or the constructor or the prototype.constructor ......yields

Trying to understand the difference between prototype and constructor in JavaScript

In certain situations, it may happen that we have `undefined` or generally *falsy* values in Array structures. For instance when reading and filling data from some unknown sources like Databases or HTML structures. Like

    var data = [42, 21, undefined, 50, 40, undefined, 9]

Since that might cause trouble when looping over such arrays and working on the elements, what is the best practice to remove `undefined` (falsy values) ?

Removing undefined values from Array

I&#39;m doing a small project to play around the goody bag the ES6 is bringing, I&#39;m trying to set register a class as an angular directive, but I&#39;m running into this error &quot;TypeError: Cannot call a class as a function&quot;, but from the examples I&#39;m finding they just write the class and register it with angular as a directive. Here&#39;s my directive.

    class dateBlock {
      constructor () {
        this.template = &#39;/app/dateblock/dateblock.html&#39;;
        this.restrict = &#39;AE&#39;;
        this.scope = {};
      }
    };

    export default dateBlock

and my index where I import it and then declare it.

    import calendarController from &#39;./calendar/calendar.js&#39;
    import dateBlock from &#39;./dateblock/dateblock.js&#39;

    function setup($stateProvider) {
        $stateProvider
          .state(&#39;base&#39;, {
            url: &#39;&#39;,
            controller: calendarController,
            templateUrl: &#39;/app/calendar/calendar.html&#39;
          });
        };

    setup.$inject = [&#39;$stateProvider&#39;]

    var app = angular.module(&#39;calApp&#39;,[&#39;ngAnimate&#39;,&#39;ui.router&#39;,&#39;hmTouchEvents&#39;, &#39;templates&#39;])
      .config(setup)
      .controller(&#39;calendarController&#39;, calendarController)
      .directive(&#39;dateBlock&#39;, dateBlock)

If I missed some crucial step I&#39;d love to hear it. Also side question is it cleaner to import all the apps components to the index and register them all there or export the app and import and register within the components?


Using ES6 Classes as Angular 1.x directives

The React way to set which option is selected for a select box, is to set a special `value` prop on the `&lt;select&gt;` itself, corresponding to the `value` attribute on the `&lt;option&gt;` element you desire to be selected. For a `multiple` select this prop can accept an array instead.

Now because this is a special attribute, I&#39;m wondering what the canonical way is to *retrieve* the selected options in the same array-of-option-values-structure when the user changes things (so I can pass it through a callback to a parent component etc), since presumably the same `value` property won&#39;t be available on the DOM element.

To use an example, with a text field you would do something like this (JSX):

    var TextComponent = React.createClass({
      handleChange: function(e) {
        var newText = e.target.value;
        this.props.someCallbackFromParent(newText);
      },
      render: function() {
        return &lt;input type=&quot;text&quot; value={this.props.someText} onChange={this.handleChange} /&gt;;
      }
    });

What is the equivalent to replace `???` for this multiple select component?

    var MultiSelectComponent = React.createClass({
      handleChange: function(e) {
        var newArrayOfSelectedOptionValues = ???;
        this.props.someCallbackFromParent(newArrayOfSelectedOptionValues);
      },
      render: function() {
        return (
          &lt;select multiple={true} value={this.props.arrayOfOptionValues} onChange={this.handleChange}&gt;
            &lt;option value={1}&gt;First option&lt;/option&gt;
            &lt;option value={2}&gt;Second option&lt;/option&gt;
            &lt;option value={3}&gt;Third option&lt;/option&gt;
          &lt;/select&gt;
        );
      }
    });

Retrieving value from &lt;select&gt; with multiple option in React

I use the Moment.js and Moment-Timezone frameworks, and have a Moment.js date object which is explicitly in UTC timezone. How can I convert that to the current timezone of the browser?

    var testDateUtc = moment.tz(&quot;2015-01-30 10:00:00&quot;, &quot;UTC&quot;);
    var localDate = ???


So it would be fine if I could find out the users local time zone; or alternatively I&#39;d like to convert the date object into another data object which just uses the &quot;local timezone&quot;, no matter what that actually is.

How to convert Moment.js date to users local timezone?

I am new to moment.js. I have a date object and it has some time associated with it. I just want to check if that date is greater than or equal to today&#39;s date, ***excluding the time when comparing.***

     var dateToCompare = 2015-04-06T18:30:00.000Z

I just want to check if dateToCompare is equal or greater than today&#39;s date.
I have checked isSame of moment.js, but it seems to take string and only the date part. But I do not want to convert my date to string or manipulate it further. Because I am worried that javascript may do something unexpected when converting that date to string(like adding the offset or dst,etc), or may be I am wrong.

Sample isSame() from docs

    moment(&#39;2010-10-20&#39;).isSame(&#39;2010-10-20&#39;);
Also I am looking for something like isSame() and isAfter() combined as one statement.

I need to compare using moment.js only.Please do not suggest plain javascript date comparison.

How to compare only date in moment.js

In using webpack to build my project, I typically require modules in CommonJS from npm modules. I need moment-timezone in my project, however in building the package you must also build all the data from moment-timezone, which can be quite a lot. 

Additionally the build is failing with the following error:

    ERROR in ./~/moment-timezone/data/packed/latest.json
    Module parse failed: /site/node_modules/moment-timezone/data/packed/latest.json Line 2: Unexpected token :
    You may need an appropriate loader to handle this file type.
    | {
    | 	&quot;version&quot;: &quot;2015a&quot;,
    | 	&quot;zones&quot;: [
    | 		&quot;Africa/Abidjan|LMT GMT|g.8 0|01|-2ldXH.Q&quot;,
    @ ./~/moment-timezone/index.js 4:15-51

At this point I am not as concerned with the build failing, as I am about the size of the build if it actually succeeds. Though, obviously the failing build will need to be addressed too at some point.

I would appreciate any pointers on how to handle this, especially if any of you have encountered this same issue using webpack (or browserify too, probably).

How should I use moment-timezone with webpack?

I would like a variable to hold yesterday&#39;s date in the format `DD-MM-YYYY` using Moment.js. So if today is 15-04-2015, I would like to subtract a day and have 14-4-2015.

I&#39;ve tried a few combinations like this:

    startdate = moment().format(&#39;DD-MM-YYYY&#39;);
    startdate.subtract(1, &#39;d&#39;);
 
and this:

    startdate = moment().format(&#39;DD-MM-YYYY&#39;).subtract(1, &#39;d&#39;);

and also this:

    startdate = moment();
    startdate.subtract(1, &#39;d&#39;);
    startdate.format(&#39;DD-MM-YYYY&#39;)

But I&#39;m not getting it...

Format date and Subtract days using Moment.js

I&#39;m using moment.js to do most of my date logic in a helper file for my React components but I haven&#39;t been able to figure out how to mock a date in Jest a la `sinon.useFakeTimers()`.

The Jest docs only speak about timer functions like `setTimeout`, `setInterval` etc but don&#39;t help with setting a date and then checking that my date functions do what they&#39;re meant to do. 

Here is some of my JS file:

```javascript
var moment = require(&#39;moment&#39;);

var DateHelper = {
  
  DATE_FORMAT: &#39;MMMM D&#39;,
  API_DATE_FORMAT: &#39;YYYY-MM-DD&#39;,
  
  formatDate: function(date) {
    return date.format(this.DATE_FORMAT);
  },

  isDateToday: function(date) {
    return this.formatDate(date) === this.formatDate(moment());
  }
};


module.exports = DateHelper;
```

and here is what I&#39;ve set up using Jest:

```javascript
jest.dontMock(&#39;../../../dashboard/calendar/date-helper&#39;)
    .dontMock(&#39;moment&#39;);

describe(&#39;DateHelper&#39;, function() {
  var DateHelper = require(&#39;../../../dashboard/calendar/date-helper&#39;),
      moment = require(&#39;moment&#39;),
      DATE_FORMAT = &#39;MMMM D&#39;;

  describe(&#39;formatDate&#39;, function() {

    it(&#39;should return the date formatted as DATE_FORMAT&#39;, function() {
      var unformattedDate = moment(&#39;2014-05-12T00:00:00.000Z&#39;),
          formattedDate = DateHelper.formatDate(unformattedDate);

      expect(formattedDate).toEqual(&#39;May 12&#39;);
    });

  });

  describe(&#39;isDateToday&#39;, function() {

    it(&#39;should return true if the passed in date is today&#39;, function() {
      var today = moment();

      expect(DateHelper.isDateToday(today)).toEqual(true);
    });
    
  });

});
```

Now these tests pass because I&#39;m using moment and my functions use moment but it seems a bit unstable and I would like to set the date to a fixed time for the tests. 

Any idea on how that could be accomplished?


Content Type	Original Author	Original Content on Stackoverflow
Question	Nelu	View Question on Stackoverflow
Solution 1 - Javascript	Nelu	View Answer on Stackoverflow
Solution 2 - Javascript	nawaz anjum	View Answer on Stackoverflow
Solution 3 - Javascript	Grini Soufyane	View Answer on Stackoverflow
Solution 4 - Javascript	venkateshwar	View Answer on Stackoverflow

.setHours(0,0,0,0) with moment.js

Javascript Problem Overview

Javascript Solutions

Solution 1 - Javascript

Solution 2 - Javascript

Solution 3 - Javascript

Solution 4 - Javascript

How do I see the expanded macro code that's causing my compile error?

Vertically align text within a UILabel (Note : Using AutoLayout)

Attributions