You should use the [`Time.IsZero()`](https://pkg.go.dev/time#Time.IsZero) function instead:

    func (Time) IsZero

or

    func (t Time) IsZero() bool
    
&gt; IsZero reports whether t represents the zero time instant, January 1, year 1, 00:00:00 UTC.


Invoking an empty `time.Time` struct literal will return Go&#39;s zero date. Thus, for the following print statement:

    fmt.Println(time.Time{})

The output is:
   
    0001-01-01 00:00:00 +0000 UTC

For the sake of completeness, the [official documentation][1] explicitly states:

&gt; The zero value of type Time is January 1, year 1, 00:00:00.000000000 UTC.


  [1]: http://golang.org/pkg/time/#Time

The zero value for time.Time is `0001-01-01 00:00:00 +0000 UTC`  See http://play.golang.org/p/vTidOlmb9P


I need to set CORS to be enabled on scripts served by express. How can I set the headers in these returned responses for public/assets?

How can I set response header on express.js assets

If I have the following array of objects:

    [ { id: 1, username: &#39;fred&#39; }, { id: 2, username: &#39;bill&#39; }, { id: 2, username: &#39;ted&#39; } ]

Is there a way to loop through the array to check whether a particular username value already exists and if it does do nothing, but if it doesn&#39;t to add a new object to the array with said username (and new ID)?

Thanks!



Check if object value exists within a Javascript array of objects and if not add a new object to array

In an error condition, I tried to return `nil`, which throws the error:

    cannot use nil as type time.Time in return argument

What is the `zero` value for `time.Time`?

What is the `zero` value for time.Time in Go?

In an error condition, I tried to return <code>nil</code>, which throws the error:
<pre><code class="hljs language-lua">cannot use nil as type time.Time in return argument
</code></pre>
What is the <code>zero</code> value for <code>time.Time</code>?

I&#39;ve been playing with Go recently and it&#39;s awesome. The thing I can&#39;t seem to figure out (after looking through documentation and blog posts) is how to get the `time.Time` type to format into whatever format I&#39;d like when it&#39;s encoded by `json.NewEncoder.Encode`

Here&#39;s a minimal Code example: 

    package main
    
    type Document struct {
        Name        string
        Content     string
        Stamp       time.Time
        Author      string
    }

    func sendResponse(data interface{}, w http.ResponseWriter, r * http.Request){
         _, err := json.Marshal(data)
        j := json.NewEncoder(w)
        if err == nil {
            encodedErr := j.Encode(data)
            if encodedErr != nil{
                //code snipped
            }
        }else{
           //code snipped
        }
    }

    func main() {
        http.HandleFunc(&quot;/document&quot;, control.HandleDocuments)
        http.ListenAndServe(&quot;localhost:4000&quot;, nil)
    }

    func HandleDocuments(w http.ResponseWriter,r *http.Request) {
        w.Header().Set(&quot;Content-Type&quot;, &quot;application/json&quot;)
        w.Header().Set(&quot;Access-Control-Allow-Origin&quot;, &quot;*&quot;)

        switch r.Method {
            case &quot;GET&quot;: 
                //logic snipped
                testDoc := model.Document{&quot;Meeting Notes&quot;, &quot;These are some notes&quot;, time.Now(), &quot;Bacon&quot;}    
                sendResponse(testDoc, w,r)
                }
            case &quot;POST&quot;:
            case &quot;PUT&quot;:
            case &quot;DELETE&quot;:
            default:
                //snipped
        }
    }

Ideally, I&#39;d like to send a request and get the Stamp field back as something like `May 15, 2014` and not `2014-05-16T08:28:06.801064-04:00`

But I&#39;m not really sure how, I know I can add `json:stamp` to the Document type declaration  to get the field to be encoded with the name stamp instead of Stamp, but I don&#39;t know what those types of things are called, so I&#39;m not even sure what to google for to find out if there is some type of formatting option in that as well. 

Does anyone have a link to the an example or good documentation page on the subject of those type mark ups (or whatever they&#39;re called) or on how I can tell the JSON encoder to handle `time.Time` fields? 

Just for reference, I have looked at these pages: [here][1] and [here][2] and of course, [at the official docs][3]


  [1]: http://pauladamsmith.com/blog/2011/05/go_time.html
  [2]: https://gobyexample.com/json
  [3]: http://golang.org/pkg/json/

How to format timestamp in outgoing JSON

How can I get Unix time in Go in milliseconds?

I have the following function:

    func makeTimestamp() int64 {
    	return time.Now().UnixNano() % 1e6 / 1e3
    }

I need less precision and only want milliseconds. 




Go time.Now().UnixNano() convert to milliseconds?

I have a while loop, and I want it to keep running through for 15 minutes. it is currently:
    
    while True:
        #blah blah blah


(this runs through, and then restarts. I need it to continue doing this except after 15 minutes it exits the loop)

Thanks!

Python loop to run for certain amount of seconds

I&#39;m running Go version 1.3 on Windows 7x64. After I run the following code I always get **2009-11-10 23:00:00 +0000 UTC**.

    package main

    import (
	    &quot;fmt&quot;
	    &quot;time&quot;
    )

    func main() {
	    fmt.Println(time.Now())
    }

I know that Go Playgroud has this fixed time for a reason, but I don&#39;t understand why I get this date in my box.

**UPDATE:**
I solved this issue by upgrading the Go version from 1.2.2 to 1.3.

Trying to reproduce the issue, I realized this had been fixed after switching the computer off and on the next day. 

I recommend to restart the computer after upgrading to 1.3.

Go time.Now() is always 2009-11-10 23:00:00 +0000 UTC

In a swift playground, I have been using

    NSDate.date() 

But, this always appears with the time element appended. For my app I need to ignore the time element. Is this possible in Swift? How can it be done? Even if I could set the time element to be the same time on every date that would work too.

Also, I am trying to compare two dates and at the moment I am using the following code:

    var earlierDate:NSDate = firstDate.earlierDate(secondDate)

Is this the only way or can I do this in a way that ignores the time element? For instance I don&#39;t want a result if they are the same day, but different times.

Comparing NSDates without time component

I&#39;m trying to copy the contents of a map ( ``amap`` ) inside another one (``aSuperMap``) and then clear  ``amap`` so that it can take  new values on the next iteration/loop. 
  The issue is that you can&#39;t clear the map [without to clear its reference][1] in the supermap as well.
 Here is some pseudo code.

    for something := range fruits{
            aMap := make(map[string]aStruct)
            aSuperMap := make(map[string]map[string]aStruct)
            
            for x := range something{
            	aMap[x] = aData
            	aSuperMap[y] = aMap
                delete(aMap, x)
        }
    //save aSuperMap
      saveASuperMap(something)
    
    }

  I&#39;ve also tried some dynamic stuff but obviously it throws an error (cannot assign to nil)

	aSuperMap[y][x] = aData

The question is how can I create an associative map ? In PHP I simply use  aSuperMap[y][x] = aData. It seems that golang doesn&#39;t have any obvious method. If I delete  ``delete(aMap, x)`` its reference from the super map is deleted as well. If I don&#39;t delete it the supermap ends up with duplicate data. Basically on each loop it gets ``aMap`` with the new value plus all the old values. 

  [1]: https://stackoverflow.com/a/23058707/3257971

How to copy a map?

I&#39;m new to interfaces and trying to do SOAP request by [github][1]  


  [1]: https://github.com/webconnex/xmlutil/blob/master/xmlutil.go

I don&#39;t understand the meaning of 

    Msg interface{}

in this code:  

    type Envelope struct {
    	Body `xml:&quot;soap:&quot;`
    }
    
    type Body struct {
    	Msg interface{}
    }

I&#39;ve observed the same syntax in

    fmt.Println

but don&#39;t understand what&#39;s being achieved by 

    interface{}

What&#39;s the meaning of interface{}?

I&#39;m running a test in Go with a statement to print something (i.e. for debugging of tests) but it&#39;s not printing anything.

    func TestPrintSomething(t *testing.T) {
    	fmt.Println(&quot;Say hi&quot;)
    }

When I run go test on this file, this is the output:

    ok  	command-line-arguments	0.004s

The only way to really get it to print, as far as I know, is to print it via t.Error(), like so: 

    func TestPrintSomethingAgain(t *testing.T) {
    	t.Error(&quot;Say hi&quot;)
    }

Which outputs this:

    Say hi
    --- FAIL: TestPrintSomethingAgain (0.00 seconds)
    	foo_test.go:35: Say hi
    FAIL
    FAIL	command-line-arguments	0.003s
    gom:  exit status 1


I&#39;ve Googled and looked through the manual but didn&#39;t find anything.

How do you print in a Go test using the &quot;testing&quot; package?

How can one remove selected keys from a map?
Is it safe to combine `delete()` with range, as in the code below?

    package main
    
    import &quot;fmt&quot;
    
    type Info struct {
    	value string
    }
    
    func main() {
    	table := make(map[string]*Info)
    	
    	for i := 0; i &lt; 10; i++ {
    		str := fmt.Sprintf(&quot;%v&quot;, i)
    		table[str] = &amp;Info{str}
    	}
    
    	for key, value := range table {
    		fmt.Printf(&quot;deleting %v=&gt;%v\n&quot;, key, value.value)
    		delete(table, key)
    	}
    }

https://play.golang.org/p/u1vufvEjSw

Is it safe to remove selected keys from map within a range loop?

I created an application that I want to run invisibly in the background (no console). How do I do this?

(This is for Windows, tested on Windows 7 Pro 64 bit)


How do I create an executable from Golang that doesn&#39;t open a console window when run?

What is best way to check if value is null or empty string in Postgres sql statements?

Value can be long expression so it is preferable that it is written only once in check.

Currently I&#39;m using:

    coalesce( trim(stringexpression),&#39;&#39;)=&#39;&#39;

But it looks a bit ugly.

`stringexpression` may be `char(n)` column or expression containing `char(n)` columns with trailing spaces.

What is best way?

Best way to check for &quot;empty or null value&quot;

What I have:
-------------

I have jQuery AJAX function that returns HTML after querying a database. Depending on the result of the query, the function will either return HTML code or nothing (i.e. blank) as desired.

What I need:
-------------

I need to conditionally check for when the data is blank.

My code:
-------------

    $.ajax({
    	type:&quot;POST&quot;,
    	url: &quot;&lt;?php echo admin_url(&#39;admin-ajax.php&#39;); ?&gt;&quot;,
    	data: associated_buildsorprojects_form,
    	success:function(data){
    		if(!data){	
    		//if(data=&quot;undefined&quot;){
    		//if(data===&quot;undefined&quot;){
    		//if(data==null){
    		//if(data.length == 0){
    		//if ( data.length != 0 ){
    		//if(data===0){
    		//if(data===&quot;0&quot;){	
    			alert(&quot;Data: &quot; + data);
    		}
    	},
    	error: function(errorThrown){
    		alert(errorThrown);
    		alert(&quot;There is an error with AJAX!&quot;);
    	}  				
    });

My problem:
-------------

I&#39;ve tried a variety of conditions but none correctly check the data. Based on my findings, a blank alert message does not mean data is 

 1. empty
 2. non-existent
 3. equal to zero
 4. of length zero
 5. null
 6. undefined

If it&#39;s none of these things, how can I therefore conditionally check for the data that yields a blank alert message?

Check if AJAX response data is empty/blank/null/undefined/0

I have a Postgres function:

    CREATE OR REPLACE FUNCTION get_stats(
        _start_date timestamp with time zone,
        _stop_date timestamp with time zone,
        id_clients integer[],
        OUT date timestamp with time zone,
        OUT profit,
        OUT cost
    )
    RETURNS SETOF record
    LANGUAGE plpgsql
    AS $$
    DECLARE
        query varchar := &#39;&#39;;
    BEGIN
    ... -- lot of code
    IF id_clients IS NOT NULL THEN
        query := query||&#39; AND id = ANY (&#39;||quote_nullable(id_clients)||&#39;)&#39;;
    END IF;
    ... -- other code
    END;
    $$;

So if I run query something like this:

    SELECT * FROM get_stats(&#39;2014-07-01 00:00:00Etc/GMT-3&#39;
                          , &#39;2014-08-06 23:59:59Etc/GMT-3&#39;, &#39;{}&#39;);

Generated query has this condition:

    &quot;... AND id = ANY(&#39;{}&#39;)...&quot;

But if an array is empty this condition should not be represented in query.  
How can I check if the array of clients is not empty?

I&#39;ve also tried two variants:

    IF ARRAY_UPPER(id_clients) IS NOT NULL THEN
        query := query||&#39; AND id = ANY (&#39;||quote_nullable(id_clients)||&#39;)&#39;;
    END IF;

And:

    IF ARRAY_LENGTH(id_clients) THEN
        query := query||&#39; AND id = ANY (&#39;||quote_nullable(id_clients)||&#39;)&#39;;
    END IF;

In both cases I got this error: `ARRAY_UPPER(ARRAY_LENGTH) doesn&#39;t exists`;

How to check if an array is empty in Postgres

I&#39;m pretty new to Guava (let&#39;s be honest, I&#39;m not &quot;pretty new&quot;, I&#39;m a complete rookie on that subject) and so I decided to go through some documentation and got quite amazed while reading this:

[`com.google.common.base.Preconditions.checkNotNull(...)`][1]

I don&#39;t get the point of this method.
This means that instead of doing : 

    myObject.getAnything();

*(which might cause a `NullPointerException` if myObject is null)*

I should use

    checkNotNull(myObject).getAnything();

which **will** throw a `NullPointerException` if `myObject` is null and return `myObject` if it is not null.

I&#39;m puzzled and this might be the stupidest question ever but ...

What is the point of this?
Those two lines do the exact same thing as for outcomes given any situations I can think of.

I don&#39;t even think that the latter is more readable.

So I must be missing something. What is it?


  [1]: https://google.github.io/guava/releases/23.0/api/docs/com/google/common/base/Preconditions.html#checkNotNull-T-

What&#39;s the point of Guava checkNotNull

I have made a request to my server in my app. And posted data something like this.Server side is waiting for all parameters even they are nil. But i couldn&#39;t add nil values to dictionary.

   

     var postDict = Dictionary&lt;String,AnyObject&gt;
     postDict[pass]=123
     postDict[name]=&quot;ali&quot;
     postDict[surname]=nil // dictionary still has only pass and name variables.

Is there a way to add nil value to dictionary ? 


Content Type	Original Author	Original Content on Stackoverflow
Question	Mingyu	View Question on Stackoverflow
Solution 1 - Time	gextra	View Answer on Stackoverflow
Solution 2 - Time	zeantsoi	View Answer on Stackoverflow
Solution 3 - Time	dethtron5000	View Answer on Stackoverflow

What is the `zero` value for time.Time in Go?

Time Problem Overview

Time Solutions

Solution 1 - Time

Solution 2 - Time

Solution 3 - Time

Check if object value exists within a Javascript array of objects and if not add a new object to array

How can I set response header on express.js assets

Attributions