
    select (string_to_array(&#39;1,2,3,4&#39;,&#39;,&#39;))[2];

I&#39;m trying to make a simple program to test the new .NET async functionality within Visual Studio 2012. I generally use BackgroundWorkers to run time-consuming code asynchronously, but sometimes it seems like a hassle for a relatively simple (but expensive) operation. The new async modifier looks like it would be great to use, but unfortunately I just can&#39;t seem to get a simple test going.

Here&#39;s my code, in a C# console application:

&lt;!-- language: c# --&gt;

    static void Main(string[] args)
    {
        string MarsResponse = await QueryRover();
        Console.WriteLine(&quot;Waiting for response from Mars...&quot;);
        Console.WriteLine(MarsResponse);
        Console.Read();
    }
    
    public static async Task&lt;string&gt; QueryRover()
    {
        await Task.Delay(5000);
        return &quot;Doin&#39; good!&quot;;
    }

I checked out some examples on MSDN and it looks to me like this code should be working, but instead I&#39;m getting a build error on the line containing &quot;await QueryRover();&quot; Am I going crazy or is something fishy happening?

Await operator can only be used within an Async method

I am trying to run a script that installs pip: get-pip.py and am getting a connection timeout due to my network being behind an HTTP proxy. Is there some way I could configure an HTTP proxy in my Python 2.7 installation to be able to install what I am trying to install?

Note: I am using Windows. Below is the error I am getting:

    C:\SetupFiles&gt;python get-pip.py
    Downloading/unpacking pip
      Cannot fetch index base URL http://pypi.python.org/simple/
      Could not find any downloads that satisfy the requirement pip
    No distributions at all found for pip



How to set an HTTP proxy in Python 2.7?

I am searching for a way to access to the Nth element of an array which is a result of `string_to_array()` function in PostgreSQL. For example,

Assume that a cell contains the string value: &quot;A simple example&quot; . If I use `string_to_array()` function, I will have an array of three strings as (&#39;A&#39;,&#39;simple&#39;,&#39;example&#39;). Now, without storing (I mean, on the fly) I want to access the 2nd element of this array, which is &#39;simple&#39;.

During my googling, I saw an example to access the last element of the array but this barely solved my problem.

Is there a way to do this?

Get Nth element of an array that returns from &quot;string_to_array()&quot; function

I am searching for a way to access to the Nth element of an array which is a result of <code>string_to_array()</code> function in PostgreSQL. For example,
Assume that a cell contains the string value: "A simple example" . If I use <code>string_to_array()</code> function, I will have an array of three strings as ('A','simple','example'). Now, without storing (I mean, on the fly) I want to access the 2nd element of this array, which is 'simple'.
During my googling, I saw an example to access the last element of the array but this barely solved my problem.
Is there a way to do this?

Struggling with a tiny problem.

I have an array:

    Array
    (
        [0] =&gt; 
        [6] =&gt; 6
        [3] =&gt; 5
        [2] =&gt; 7
    )

I am checking if a set value is in the array.

    if(in_array(5, $array)) {
    //do something
    } else {
    // do something else
    }

The thing is, when it find the value 5 in array, I really need the key to work with in my &quot;do something&quot;.

In this case I need to set:

    $key = 3;

(key from the found value in_array).

Any suggestions?

PHP if in_array() how to get the key as well?

I have an array of hashes like so:

     [{&quot;testPARAM1&quot;=&gt;&quot;testVAL1&quot;}, {&quot;testPARAM2&quot;=&gt;&quot;testVAL2&quot;}]

And I&#39;m trying to map this onto single hash like this:

    {&quot;testPARAM2&quot;=&gt;&quot;testVAL2&quot;, &quot;testPARAM1&quot;=&gt;&quot;testVAL1&quot;}

I have achieved it using

      par={}
      mitem[&quot;params&quot;].each { |h| h.each {|k,v| par[k]=v} } 

But I was wondering if it&#39;s possible to do this in a more idiomatic way (preferably without using a local variable).

How can I do this?


Rails mapping array of hashes onto single hash

I have a nested data structure containing objects and arrays. How can I extract the information, i.e. access a specific or multiple values (or keys)?

For example:

    var data = {
        code: 42,
        items: [{
            id: 1,
            name: &#39;foo&#39;
        }, {
            id: 2,
            name: &#39;bar&#39;
        }]
    };

How could I access the `name` of the second item in `items`?

How can I access and process nested objects, arrays or JSON?

I&#39;m trying to calculate the total, mean and median of an array thats populated by input received by a textfield. I&#39;ve managed to work out the total and the mean, I just can&#39;t get the median to work. I think the array needs to be sorted before I can do this, but I&#39;m not sure how to do this. Is this the problem, or is there another one that I didn&#39;t find? Here is my code:

    import java.applet.Applet;
    import java.awt.Graphics;
    import java.awt.*;
    import java.awt.event.*;
    
    public class whileloopq extends Applet implements ActionListener
    {
    	Label label;
    	TextField input;
    	int num;
    	int index;
    	int[] numArray = new int[20];
    	int sum;
    	int total;
    	double avg;
    	int median;
    
    
    
    	public void init ()
    	{
    		label = new Label(&quot;Enter numbers&quot;);
    		input = new TextField(5);
    		add(label);
    		add(input);
    		input.addActionListener(this);
    		index = 0;
    	}
    
    	public void actionPerformed (ActionEvent ev)
    	{
            int num = Integer.parseInt(input.getText());
    		numArray[index] = num;
    		index++;
    		if (index == 20)
    		input.setEnabled(false);
    			input.setText(&quot;&quot;);
    	    sum = 0;
    		for (int i = 0; i &lt; numArray.length; i++)
    		{
    			sum += numArray[i];
    		}
            total = sum;
            avg = total / index;
    
            median = numArray[numArray.length/2];
    
    
    
            repaint();
    
    	}
    
    
    
    	public void paint (Graphics graf)
    	{
    
    
    
    		graf.drawString(&quot;Total   = &quot; + Integer.toString(total), 25, 85);
    		graf.drawString(&quot;Average = &quot; + Double.toString(avg), 25, 100);
    		graf.drawString(&quot;Median = &quot; + Integer.toString(median), 25, 115);
    
    
    
    	}
    }

How to calculate the median of an array?

I am creating the following array from data attributes and I need to be able to grab the highest and lowest value from it so I can pass it to another function later on.


    var allProducts = $(products).children(&quot;li&quot;);
    prices = []
    $(allProducts).each(function () {
        var price = parseFloat($(this).data(&#39;price&#39;));
        prices[price] = price;
    });
    console.log(prices[0]) &lt;!-- this returns undefined


My list items look like this (I have cut down for readability):

    &lt;li data-price=&quot;29.97&quot;&gt;&lt;a href=&quot;#&quot;&gt;Product&lt;/a&gt;&lt;/li&gt;
    &lt;li data-price=&quot;31.00&quot;&gt;&lt;a href=&quot;#&quot;&gt;Product&lt;/a&gt;&lt;/li&gt;
    &lt;li data-price=&quot;19.38&quot;&gt;&lt;a href=&quot;#&quot;&gt;Product&lt;/a&gt;&lt;/li&gt;
    &lt;li data-price=&quot;20.00&quot;&gt;&lt;a href=&quot;#&quot;&gt;Product&lt;/a&gt;&lt;/li&gt;

A quick console.log on prices shows me my array which appears to be sorted so I could grab the first and last element I assume, but presently the names and values in the array are the same so whenever I try and do a prices[0], I get *undefined*

    []
    19.38   19.38
    20.00   20.00
    29.97   29.97
    31.00   31.00

Got a feeling this is a stupidly easy question, so please be kind :)

Get max and min value from array in JavaScript

I&#39;m developing an app on Heroku with a Postgresql backend. Periodically, I get this error message when trying to access the database, both from the CLI and from loading a page on the server:

    psql: FATAL: remaining connection slots are reserved for non-replication superuser connections

Anyone seen this before or please help point me in the right direction?

Heroku &quot;psql: FATAL: remaining connection slots are reserved for non-replication superuser connections&quot;

How do I invoke a postgresql sequence while inserting new row into a table?

I want to do something like this:

    insert into biz_term(
      biz_term_id, 
      biz_term_name, 
      ) 
    values(SELECT nextval(idsequence)&#39;,
    &#39;temp&#39;
    );

I want to do it because when I am trying to insert new record into `biz_term` table then sequence `idsequence` is not getting invoked directly.  How to invoke it?

How to invoke sequence while inserting new record into postgresql table?

I&#39;m writing a function in PL/pgSQL, and I&#39;m looking for the simplest way to check if a row exists.  
Right now I&#39;m SELECTing an `integer` into a `boolean`, which doesn&#39;t really work. I&#39;m not experienced with PL/pgSQL enough yet to know the best way of doing this.

Here&#39;s part of my function:

    DECLARE person_exists boolean;
    BEGIN

    person_exists := FALSE;

    SELECT &quot;person_id&quot; INTO person_exists
      FROM &quot;people&quot; p
    WHERE p.person_id = my_person_id
    LIMIT 1;

    IF person_exists THEN
      -- Do something
    END IF;

    END; $$ LANGUAGE plpgsql;

*Update* - I&#39;m doing something like this for now:

    DECLARE person_exists integer;
    BEGIN

    person_exists := 0;

    SELECT count(&quot;person_id&quot;) INTO person_exists
      FROM &quot;people&quot; p
    WHERE p.person_id = my_person_id
    LIMIT 1;

    IF person_exists &lt; 1 THEN
      -- Do something
    END IF;

PL/pgSQL checking if a row exists

Let say you have a `SELECT id from table` query (the real case is a complex query) that does return you several results.

The problem is how to get all `id` return in a single row, comma separated?


PostgreSQL query to return results as a comma separated list

I&#39;m setting up my PostgreSQL 9.1. I can&#39;t do anything with PostgreSQL: can&#39;t `createdb`, can&#39;t `createuser`; all operations return the error message

    Fatal: role h9uest does not exist

`h9uest` is my account name, and I `sudo apt-get install` PostgreSQL 9.1 under this account.  
Similar error persists for the `root` account.

Content Type	Original Author	Original Content on Stackoverflow
Question	iso_9001_	View Question on Stackoverflow
Solution 1 - Arrays	devanand	View Answer on Stackoverflow

Get Nth element of an array that returns from "string_to_array()" function

Arrays Problem Overview

Arrays Solutions

Solution 1 - Arrays

How to set an HTTP proxy in Python 2.7?

Await operator can only be used within an Async method

Attributions