Programs & Examples On #Compile time constant

Java switch statement: Constant expression required, but it IS constant

Because those are not compile time constants. Consider the following valid code:

public static final int BAR = new Random().nextInt();

You can only know the value of BAR in runtime.

Form/JavaScript not working on IE 11 with error DOM7011

I run into this when click on a html , it is fixed by adding type = "button" attribute.

Return array from function

neater:

function BlockID() {
  return {
    "s":"Images/Block_01.png",
    "g":"Images/Block_02.png",
    "C":"Images/Block_03.png",
    "d":"Images/Block_04.png"
   }
}

or just

var images = {
  "s":"Images/Block_01.png",
  "g":"Images/Block_02.png",
  "C":"Images/Block_03.png",
  "d":"Images/Block_04.png"
}

No function matches the given name and argument types

Your function has a couple of smallint parameters.
But in the call, you are using numeric literals that are presumed to be type integer.

A string literal or string constant ('123') is not typed immediately. It remains type "unknown" until assigned or cast explicitly.

However, a numeric literal or numeric constant is typed immediately. Per documentation:

A numeric constant that contains neither a decimal point nor an exponent is initially presumed to be type integer if its value fits in type integer (32 bits); otherwise it is presumed to be type bigint if its value fits in type bigint (64 bits); otherwise it is taken to be type numeric. Constants that contain decimal points and/or exponents are always initially presumed to be type numeric.

More explanation and links in this related answer:

Solution

Add explicit casts for the smallint parameters or quote them.

Demo

CREATE OR REPLACE FUNCTION f_typetest(smallint)
  RETURNS bool AS 'SELECT TRUE' LANGUAGE sql;

Incorrect call:

SELECT * FROM f_typetest(1);

Correct calls:

SELECT * FROM f_typetest('1');
SELECT * FROM f_typetest(smallint '1');
SELECT * FROM f_typetest(1::int2);
SELECT * FROM f_typetest('1'::int2);

db<>fiddle here
Old sqlfiddle.

Use of symbols '@', '&', '=' and '>' in custom directive's scope binding: AngularJS

When we create a customer directive, the scope of the directive could be in Isolated scope, It means the directive does not share a scope with the controller; both directive and controller have their own scope. However, data can be passed to the directive scope in three possible ways.

  1. Data can be passed as a string using the @ string literal, pass string value, one way binding.
  2. Data can be passed as an object using the = string literal, pass object, 2 ways binding.
  3. Data can be passed as a function the & string literal, calls external function, can pass data from directive to controller.

How can I get CMake to find my alternative Boost installation?

There is a generic method to give CMake directions about where to find libraries.

When looking for a library, CMake looks first in the following variables:

  • CMAKE_LIBRARY_PATH and LD_LIBRARY_PATH for libraries
  • CMAKE_INCLUDE_PATH and INCLUDE_PATH for includes

If you declare your Boost files in one of the environment variables, CMake will find it. Example:

export CMAKE_LIBRARY_PATH="/stuff/lib.boost.1.52/lib:$CMAKE_LIBRARY_PATH"
export CMAKE_INCLUDE_PATH="/stuff/lib.boost.1.52/include:$CMAKE_INCLUDE_PATH"

If it's too cumbersome, you can also use a nice installing tool I wrote that will do everything for you: C++ version manager

What does collation mean?

The collation is how SQL server decides on how to sort and compare text.

See MSDN.

Is it possible to have a multi-line comments in R?

if(FALSE) {
...
}

precludes multiple lines from being executed. However, these lines still have to be syntactically correct, i.e., can't be comments in the proper sense. Still helpful for some cases though.

How to download Javadoc to read offline?

For the download of latest java documentation(jdk-8u77) API

Navigate to http://www.oracle.com/technetwork/java/javase/downloads/index.html

Under Addition Resources and Under Java SE 8 Documentation
Click Download button

Under Java SE Development Kit 8 Documentation > Java SE Development Kit 8u77 Documentation

Accept the License Agreement and click on the download zip file

Unzip the downloaded file Start the API docs from jdk-8u77-docs-all\docs\api\index.html

For the other java versions api download, follow the following steps.

Navigate to http://docs.oracle.com/javase/

From Release dropdown select either of Java SE 7/6/5

In corresponding JAVA SE page and under Downloads left side menu Click JDK 7/6/5 Documentation or Java SE Documentation

Now in next page select the appropriate Java SE Development Kit 7uXX Documentation.

Accept License Agreement and click on Download zip file

Unzip the file and Start the API docs from
jdk-7uXX-docs-all\docs\api\index.html

How do I convert array of Objects into one Object in JavaScript?

Using Underscore.js:

var myArray = [
  Object { key="11", value="1100", $$hashKey="00X"},
  Object { key="22", value="2200", $$hashKey="018"}
];
var myObj = _.object(_.pluck(myArray, 'key'), _.pluck(myArray, 'value'));

How to convert an NSString into an NSNumber

I know this is very late but below code is working for me.

Try this code

NSNumber *number = @([dictionary[@"keyValue"] intValue]]);

This may help you. Thanks

PHP is not recognized as an internal or external command in command prompt

Add C:\xampp\php to your PATH environment variable.(My Computer->properties -> Advanced system setting-> Environment Variables->edit path)

Then close your command prompt and restart again.

Note: It's very important to close your command prompt and restart again otherwise changes will not be reflected.

Check if an array contains duplicate values

This should work with only one loop:

function checkIfArrayIsUnique(arr) {
    var map = {}, i, size;

    for (i = 0, size = arr.length; i < size; i++){
        if (map[arr[i]]){
            return false;
        }

        map[arr[i]] = true;
    }

    return true;
}

JUNIT Test class in Eclipse - java.lang.ClassNotFoundException

Another possible problem is a missing builder (it will prevent from your .class file from being built).

Check that your .project file has the following lines

<buildSpec>
  <buildCommand>
    <name>org.eclipse.jdt.core.javabuilder</name>
    <arguments>
    </arguments>
  </buildCommand>
</buildSpec>
<natures>
  <nature>org.eclipse.jdt.core.javanature</nature>
</natures>

Remove Backslashes from Json Data in JavaScript

You need to deserialize the JSON once before returning it as response. Please refer below code. This works for me:

JavaScriptSerializer jss = new JavaScriptSerializer();
Object finalData = jss.DeserializeObject(str);

can you host a private repository for your organization to use with npm?

There is an easy to use npm package to do this. https://www.npmjs.org/package/sinopia

In a nutshell, Sinopia is a private/caching npm repository server that you can setup with zero configuration.

Sinopia can be used to :

  • publish own private packages without exposing it to the public
  • cache only public packages that are used (there is no need to have to replicate the whole public registery)
  • override public packages with a modified version that have been produced internally.

HttpServletRequest get JSON POST data

Normaly you can GET and POST parameters in a servlet the same way:

request.getParameter("cmd");

But only if the POST data is encoded as key-value pairs of content type: "application/x-www-form-urlencoded" like when you use a standard HTML form.

If you use a different encoding schema for your post data, as in your case when you post a json data stream, you need to use a custom decoder that can process the raw datastream from:

BufferedReader reader = request.getReader();

Json post processing example (uses org.json package )

public void doPost(HttpServletRequest request, HttpServletResponse response)
  throws ServletException, IOException {

  StringBuffer jb = new StringBuffer();
  String line = null;
  try {
    BufferedReader reader = request.getReader();
    while ((line = reader.readLine()) != null)
      jb.append(line);
  } catch (Exception e) { /*report an error*/ }

  try {
    JSONObject jsonObject =  HTTP.toJSONObject(jb.toString());
  } catch (JSONException e) {
    // crash and burn
    throw new IOException("Error parsing JSON request string");
  }

  // Work with the data using methods like...
  // int someInt = jsonObject.getInt("intParamName");
  // String someString = jsonObject.getString("stringParamName");
  // JSONObject nestedObj = jsonObject.getJSONObject("nestedObjName");
  // JSONArray arr = jsonObject.getJSONArray("arrayParamName");
  // etc...
}

Android get Current UTC time

see my answer here:

How can I get the current date and time in UTC or GMT in Java?

I've fully tested it by changing the timezones on the emulator

Split Strings into words with multiple word boundary delimiters

I had to come up with my own solution since everything I've tested so far failed at some point.

>>> import re
>>> def split_words(text):
...     rgx = re.compile(r"((?:(?<!'|\w)(?:\w-?'?)+(?<!-))|(?:(?<='|\w)(?:\w-?'?)+(?=')))")
...     return rgx.findall(text)

It seems to be working fine, at least for the examples below.

>>> split_words("The hill-tops gleam in morning's spring.")
['The', 'hill-tops', 'gleam', 'in', "morning's", 'spring']
>>> split_words("I'd say it's James' 'time'.")
["I'd", 'say', "it's", "James'", 'time']
>>> split_words("tic-tac-toe's tic-tac-toe'll tic-tac'tic-tac we'll--if tic-tac")
["tic-tac-toe's", "tic-tac-toe'll", "tic-tac'tic-tac", "we'll", 'if', 'tic-tac']
>>> split_words("google.com [email protected] split_words")
['google', 'com', 'email', 'google', 'com', 'split_words']
>>> split_words("Kurt Friedrich Gödel (/'g??rd?l/;[2] German: ['k???t 'gø?dl?] (listen);")
['Kurt', 'Friedrich', 'Gödel', ''g??rd?l', '2', 'German', ''k??', 't', ''gø?dl', 'listen']
>>> split_words("April 28, 1906 – January 14, 1978) was an Austro-Hungarian-born Austrian...")
['April', '28', '1906', 'January', '14', '1978', 'was', 'an', 'Austro-Hungarian-born', 'Austrian']

Cannot set property 'display' of undefined

document.getElementsByClassName('btn-pageMenu') delivers a nodeList. You should use: document.getElementsByClassName('btn-pageMenu')[0].style.display (if it's the first element from that list you want to change.

If you want to change style.display for all nodes loop through the list:

var elems = document.getElementsByClassName('btn-pageMenu');
for (var i=0;i<elems.length;i+=1){
  elems[i].style.display = 'block';
}

to be complete: if you use jquery it is as simple as:

?$('.btn-pageMenu').css('display'???????????????????????????,'block');??????

getResourceAsStream() vs FileInputStream

classname.getResourceAsStream() loads a file via the classloader of classname. If the class came from a jar file, that is where the resource will be loaded from.

FileInputStream is used to read a file from the filesystem.

Why does JSON.parse fail with the empty string?

Because '' is not a valid Javascript/JSON object. An empty object would be '{}'

For reference: https://developer.mozilla.org/en/docs/Web/JavaScript/Reference/Global_Objects/JSON/parse

Git diff -w ignore whitespace only at start & end of lines

This is an old question, but is still regularly viewed/needed. I want to post to caution readers like me that whitespace as mentioned in the OP's question is not the same as Regex's definition, to include newlines, tabs, and space characters -- Git asks you to be explicit. See some options here: https://git-scm.com/book/en/v2/Customizing-Git-Git-Configuration

As stated, git diff -b or git diff --ignore-space-change will ignore spaces at line ends. If you desire that setting to be your default behavior, the following line adds that intent to your .gitconfig file, so it will always ignore the space at line ends:

git config --global core.whitespace trailing-space

In my case, I found this question because I was interested in ignoring "carriage return whitespace differences", so I needed this:

git diff --ignore-cr-at-eol or git config --global core.whitespace cr-at-eol from here.

You can also make it the default only for that repo by omitting the --global parameter, and checking in the settings file for that repo. For the CR problem I faced, it goes away after check-in if warncrlf or autocrlf = true in the [core] section of the .gitconfig file.

SQL using sp_HelpText to view a stored procedure on a linked server

Little addition in answer if you have different user rather then dbo then do like this.

EXEC  [ServerName].[DatabaseName].dbo.sp_HelpText '[user].[storedProcName]'

How to efficiently change image attribute "src" from relative URL to absolute using jQuery?

change image captcha refresh

html:

 <img id="captcha_img" src="http://localhost/captcha.php" /> 

jquery:

$("#captcha_img").click(function()
    {
        var capt_rand=Math.floor((Math.random() * 9999) + 1);
        $("#captcha_img").attr("src","http://localhost/captcha.php?" + capt_rand);
    });

Dropdown select with images

If you think about it the concept behind a dropdown select it's pretty simple. For what you're trying to accomplish, a simple <ul> will do.

<ul id="menu">
    <li>
        <a href="#"><img src="" alt=""/></a> <!-- Selected -->
        <ul>
            <li><a href="#"><img src="" alt=""/></a></li>
            <li><a href="#"><img src="" alt=""/></a></li>
            <li><a href="#"><img src="" alt=""/></a></li>
            <li><a href="#"><img src="" alt=""/></a></li>
        </ul>
    </li>
</ul>

You style it with css and then some simple jQuery will do. I haven't tried this tho:

$('#menu ul li').click(function(){
    var $a = $(this).find('a');
    $(this).parents('#menu').children('li a').replaceWith($a).
});

Firefox "ssl_error_no_cypher_overlap" error

Given what you've tried and the error messages, I'd say this was more to do with the exact cipher algorithm used rather than the TLS/SSL version. Are you using a non-Sun JRE by any chance, or a different vendor's security implementation? Try a different JRE/OS to test your server if you can. Failing that you might just be able to see what's going on with Wireshark (with a filter of 'tcp.port == 443').

How can I turn a DataTable to a CSV?

Try changing sb.Append(Environment.NewLine); to sb.AppendLine();.

StringBuilder sb = new StringBuilder();          
foreach (DataColumn col in dt.Columns)         
{             
    sb.Append(col.ColumnName + ',');         
}          

sb.Remove(sb.Length - 1, 1);         
sb.AppendLine();          

foreach (DataRow row in dt.Rows)         
{             
    for (int i = 0; i < dt.Columns.Count; i++)             
    {                 
        sb.Append(row[i].ToString() + ",");             
    }              

    sb.AppendLine();         
}          

File.WriteAllText("test.csv", sb.ToString());

Convert string to JSON array

you will need to convert given string to JSONObject instead of JSONArray because current String contain JsonObject as root element instead of JsonArray :

JSONObject jsonObject = new JSONObject(readlocationFeed);

What are the benefits of using C# vs F# or F# vs C#?

F# is essentially the C++ of functional programming languages. They kept almost everything from Objective Caml, including the really stupid parts, and threw it on top of the .NET runtime in such a way that it brings in all the bad things from .NET as well.

For example, with Objective Caml you get one type of null, the option<T>. With F# you get three types of null, option<T>, Nullable<T>, and reference nulls. This means if you have an option you need to first check to see if it is "None", then you need to check if it is "Some(null)".

F# is like the old Java clone J#, just a bastardized language just to attract attention. Some people will love it, a few of those will even use it, but in the end it is still a 20-year-old language tacked onto the CLR.

Is there a link to the "latest" jQuery library on Google APIs?

Don’t Use jquery-latest.js

This file is no longer updated (it'll be on v1.11.1 forever). Furthermore it has a very short cache life, (wiping out the benefits of using a CDN) so you'd be better of selecting a version of jQuery instead.

More details on the jQuery blog: http://blog.jquery.com/2014/07/03/dont-use-jquery-latest-js/

Where is the Global.asax.cs file?

That's because you created a Web Site instead of a Web Application. The cs/vb files can only be seen in a Web Application, but in a website you can't have a separate cs/vb file.

Edit: In the website you can add a cs file behavior like..

<%@ Application CodeFile="Global.asax.cs" Inherits="ApplicationName.MyApplication" Language="C#" %>

~/Global.asax.cs:

namespace ApplicationName
{
    public partial class MyApplication : System.Web.HttpApplication
    {
        protected void Application_Start()
        {
        }
    }
}

Ruby: How to iterate over a range, but in set increments?

You can use Numeric#step.

0.step(30,5) do |num|
  puts "number is #{num}"
end
# >> number is 0
# >> number is 5
# >> number is 10
# >> number is 15
# >> number is 20
# >> number is 25
# >> number is 30

How do I get HTTP Request body content in Laravel?

You can pass data as the third argument to call(). Or, depending on your API, it's possible you may want to use the sixth parameter.

From the docs:

$this->call($method, $uri, $parameters, $files, $server, $content);

Simple pthread! C++

When compiling with G++, remember to put the -lpthread flag :)

How to set ID using javascript?

Do you mean like this?

var hello1 = document.getElementById('hello1');
hello1.id = btoa(hello1.id);

To further the example, say you wanted to get all elements with the class 'abc'. We can use querySelectorAll() to accomplish this:

HTML

<div class="abc"></div>
<div class="abc"></div>

JS

var abcElements = document.querySelectorAll('.abc');

// Set their ids
for (var i = 0; i < abcElements.length; i++)
    abcElements[i].id = 'abc-' + i;

This will assign the ID 'abc-<index number>' to each element. So it would come out like this:

<div class="abc" id="abc-0"></div>
<div class="abc" id="abc-1"></div>

To create an element and assign an id we can use document.createElement() and then appendChild().

var div = document.createElement('div');
div.id = 'hello1';

var body = document.querySelector('body');
body.appendChild(div);

Update

You can set the id on your element like this if your script is in your HTML file.

<input id="{{str(product["avt"]["fto"])}}" >
<span>New price :</span>
<span class="assign-me">

<script type="text/javascript">
    var s = document.getElementsByClassName('assign-me')[0];
    s.id = btoa({{str(produit["avt"]["fto"])}});
</script>

Your requirements still aren't 100% clear though.

Convert number of minutes into hours & minutes using PHP

@Martin Bean's answer is perfectly correct but in my point of view it needs some refactoring to fit what a regular user would expect from a website (web system).
I think that when minutes are below 10 a leading zero must be added.
ex: 10:01, not 10:1

I changed code to accept $time = 0 since 0:00 is better than 24:00.

One more thing - there is no case when $time is bigger than 1439 - which is 23:59 and next value is simply 0:00.

function convertToHoursMins($time, $format = '%d:%s') {
    settype($time, 'integer');
    if ($time < 0 || $time >= 1440) {
        return;
    }
    $hours = floor($time/60);
    $minutes = $time%60;
    if ($minutes < 10) {
        $minutes = '0' . $minutes;
    }
    return sprintf($format, $hours, $minutes);
}

Black transparent overlay on image hover with only CSS?

You were close. This will work:

.image { position: relative; border: 1px solid black; width: 200px; height: 200px; }
.image img { max-width: 100%; max-height: 100%; }
.overlay { position: absolute; top: 0; left: 0; right:0; bottom:0; display: none; background-color: rgba(0,0,0,0.5); }
.image:hover .overlay { display: block; }

You needed to put the :hover on image, and make the .overlay cover the whole image by adding right:0; and bottom:0.

jsfiddle: http://jsfiddle.net/Zf5am/569/

How to position three divs in html horizontally?

I know this is a very old question. Just posting this here as I solved this problem using FlexBox. Here is the solution

_x000D_
_x000D_
#container {
  height: 100%;
  width: 100%;
  display: flex;
}
#leftThing {
  width: 25%;
  background-color: blue;
}
#content {
  width: 50%;
  background-color: green;
}
#rightThing {
  width: 25%;
  background-color: yellow;
}
_x000D_
<div id="container">

  <div id="leftThing">
    Left Side Menu
  </div>

  <div id="content">
    Random Content
  </div>

  <div id="rightThing">
    Right Side Menu
  </div>

</div>
_x000D_
_x000D_
_x000D_

Just had to add display:flex to the container! No floats required.

stop service in android

onDestroyed()

is wrong name for

onDestroy()  

Did you make a mistake only in this question or in your code too?

Uncaught ReferenceError: $ is not defined

I had this issue, when I was browsing internet through my mobile hotspot. it was also compressing images and added the following script at the bottom of body tag

<script language="javascript"><!--
bmi_SafeAddOnload(bmi_load,"bmi_orig_img");//-->
</script>

When I connected to proper wifi connection, all seems to work find for me. Hope this help someone.

HTTP GET Request in Node.js Express

Check out httpreq: it's a node library I created because I was frustrated there was no simple http GET or POST module out there ;-)

JavaScript: undefined !== undefined?

It turns out that you can set window.undefined to whatever you want, and so get object.x !== undefined when object.x is the real undefined. In my case I inadvertently set undefined to null.

The easiest way to see this happen is:

window.undefined = null;
alert(window.xyzw === undefined); // shows false

Of course, this is not likely to happen. In my case the bug was a little more subtle, and was equivalent to the following scenario.

var n = window.someName; // someName expected to be set but is actually undefined
window[n]=null; // I thought I was clearing the old value but was actually changing window.undefined to null
alert(window.xyzw === undefined); // shows false

What is the difference between an int and a long in C++?

The C++ specification itself (old version but good enough for this) leaves this open.

There are four signed integer types: 'signed char', 'short int', 'int', and 'long int'. In this list, each type provides at least as much storage as those preceding it in the list. Plain ints have the natural size suggested by the architecture of the execution environment* ;

[Footnote: that is, large enough to contain any value in the range of INT_MIN and INT_MAX, as defined in the header <climits>. --- end foonote]

Disable validation of HTML5 form elements

The best solution is to use a text input and add the attribute inputmode="url" to provide the URL keyboard facilities. The HTML5 specification was thought for this purpose. If you keep type="url" you get the syntax validation which is not useful in every case (it is better to check if it returns a 404 error instead of the syntax which is quite permissive and is not of a great help).

You also have the possibility to override the default pattern with the attribute pattern="https?://.+" for example to be more permissive.

Putting the novalidate attribute to the form is not the right answer to the asked question because it removes validation for all the fields in the form and you may want to keep validation for email fields for example.

Using jQuery to disable validation is also a bad solution because it should absolutely work without JavaScript.

In my case, I put a select element with 2 options (http:// or https://) before the URL input because I just need websites (and no ftp:// or other things). This way I avoid typing this weird prefix (the biggest regret of Tim Berners-Lee and maybe the main source of URL syntax errors) and I use a simple text input with inputmode="url" with placeholders (without HTTP). I use jQuery and server side script to validate the real existence of the web site (no 404) and to remove the HTTP prefix if inserted (I avoid to use a pattern like pattern="^((?http).)*$" to prevent putting the prefix because I think it is better to be more permissive)

SQL ORDER BY multiple columns

yes,the sorting proceed differently. in first scenario, orders based on column1 and in addition to that process further by sorting colmun2 based on column1 .. in second scenario ,it orders completely based on column 1 only... please proceed with a simple example...u will get quickly..

Replace non-ASCII characters with a single space

If the replacement character can be '?' instead of a space, then I'd suggest result = text.encode('ascii', 'replace').decode():

"""Test the performance of different non-ASCII replacement methods."""


import re
from timeit import timeit


# 10_000 is typical in the project that I'm working on and most of the text
# is going to be non-ASCII.
text = 'Æ' * 10_000


print(timeit(
    """
result = ''.join([c if ord(c) < 128 else '?' for c in text])
    """,
    number=1000,
    globals=globals(),
))

print(timeit(
    """
result = text.encode('ascii', 'replace').decode()
    """,
    number=1000,
    globals=globals(),
))

Results:

0.7208260721400134
0.009975979187503592

How to get Enum Value from index in Java?

I recently had the same problem and used the solution provided by Harry Joy. That solution only works with with zero-based enumaration though. I also wouldn't consider it save as it doesn't deal with indexes that are out of range.

The solution I ended up using might not be as simple but it's completely save and won't hurt the performance of your code even with big enums:

public enum Example {

    UNKNOWN(0, "unknown"), ENUM1(1, "enum1"), ENUM2(2, "enum2"), ENUM3(3, "enum3");

    private static HashMap<Integer, Example> enumById = new HashMap<>();
    static {
        Arrays.stream(values()).forEach(e -> enumById.put(e.getId(), e));
    }

    public static Example getById(int id) {
        return enumById.getOrDefault(id, UNKNOWN);
    }

    private int id;
    private String description;

    private Example(int id, String description) {
        this.id = id;
        this.description= description;
    }

    public String getDescription() {
        return description;
    }

    public int getId() {
        return id;
    }
}

If you are sure that you will never be out of range with your index and you don't want to use UNKNOWN like I did above you can of course also do:

public static Example getById(int id) {
        return enumById.get(id);
}

How to enable cURL in PHP / XAMPP

Since XAMPP went through some modifications, the file is now at xampp/php/php.ini.

What .NET collection provides the fastest search

Have you considered List.BinarySearch(item)?

You said that your large collection is already sorted so this seems like the perfect opportunity? A hash would definitely be the fastest, but this brings about its own problems and requires a lot more overhead for storage.

How to replace text of a cell based on condition in excel

You can use the Conditional Formatting to replace text and NOT effect any formulas. Simply go to the Rule's format where you will see Number, Font, Border and Fill.
Go to the Number tab and select CUSTOM. Then simply type where it says TYPE: what you want to say in QUOTES.

Example.. "OTHER"

log4net vs. Nlog

For anyone getting to this thread late, you may want to take a look back at the .Net Base Class Library (BCL). Many people missed the changes between .Net 1.1 and .Net 2.0 when the TraceSource class was introduced (circa 2005).

Using the TraceSource is analagous to other logging frameworks, with granular control of logging, configuration in app.config/web.config, and programmatic access - without the overhead of the enterprise application block.

There are also a number of comparisons floating around: "log4net vs TraceSource"

How to make a copy of an object in C#

Properties in your object are value types and you can use the shallow copy in such situation like that:

obj myobj2 = (obj)myobj.MemberwiseClone();

But in other situations, like if any members are reference types, then you need Deep Copy. You can get a deep copy of an object using Serialization and Deserialization techniques with the help of BinaryFormatter class:

public static T DeepCopy<T>(T other)
{
    using (MemoryStream ms = new MemoryStream())
    {
        BinaryFormatter formatter = new BinaryFormatter();
        formatter.Context = new StreamingContext(StreamingContextStates.Clone);
        formatter.Serialize(ms, other);
        ms.Position = 0;
        return (T)formatter.Deserialize(ms);
    }
}

The purpose of setting StreamingContext: We can introduce special serialization and deserialization logic to our code with the help of either implementing ISerializable interface or using built-in attributes like OnDeserialized, OnDeserializing, OnSerializing, OnSerialized. In all cases StreamingContext will be passed as an argument to the methods(and to the special constructor in case of ISerializable interface). With setting ContextState to Clone, we are just giving hint to that method about the purpose of the serialization.

Additional Info: (you can also read this article from MSDN)

Shallow copying is creating a new object and then copying the nonstatic fields of the current object to the new object. If a field is a value type, a bit-by-bit copy of the field is performed; for a reference type, the reference is copied but the referred object is not; therefore the original object and its clone refer to the same object.

Deep copy is creating a new object and then copying the nonstatic fields of the current object to the new object. If a field is a value type, a bit-by-bit copy of the field is performed. If a field is a reference type, a new copy of the referred object is performed.

Get href attribute on jQuery

Use $(this) for get the desire element.

function openAll()
{
     $("tr.b_row").each(function(){
        var a_href = $(this).find('.cpt h2 a').attr('href');
        alert ("Href is: "+a_href);
     });
}

Android Split string

You might also want to consider the Android specific TextUtils.split() method.

The difference between TextUtils.split() and String.split() is documented with TextUtils.split():

String.split() returns [''] when the string to be split is empty. This returns []. This does not remove any empty strings from the result.

I find this a more natural behavior. In essence TextUtils.split() is just a thin wrapper for String.split(), dealing specifically with the empty-string case. The code for the method is actually quite simple.

fs: how do I locate a parent folder?

Try this:

fs.readFile(__dirname + '/../../foo.bar');

Note the forward slash at the beginning of the relative path.

How do you delete an ActiveRecord object?

There is delete, delete_all, destroy, and destroy_all.

The docs are: older docs and Rails 3.0.0 docs

delete doesn't instantiate the objects, while destroy does. In general, delete is faster than destroy.

Calling Objective-C method from C++ member function?

You can mix C++ with Objective-C if you do it carefully. There are a few caveats but generally speaking they can be mixed. If you want to keep them separate, you can set up a standard C wrapper function that gives the Objective-C object a usable C-style interface from non-Objective-C code (pick better names for your files, I have picked these names for verbosity):

MyObject-C-Interface.h

#ifndef __MYOBJECT_C_INTERFACE_H__
#define __MYOBJECT_C_INTERFACE_H__

// This is the C "trampoline" function that will be used
// to invoke a specific Objective-C method FROM C++
int MyObjectDoSomethingWith (void *myObjectInstance, void *parameter);
#endif

MyObject.h

#import "MyObject-C-Interface.h"

// An Objective-C class that needs to be accessed from C++
@interface MyObject : NSObject
{
    int someVar;
}

// The Objective-C member function you want to call from C++
- (int) doSomethingWith:(void *) aParameter;
@end

MyObject.mm

#import "MyObject.h"

@implementation MyObject

// C "trampoline" function to invoke Objective-C method
int MyObjectDoSomethingWith (void *self, void *aParameter)
{
    // Call the Objective-C method using Objective-C syntax
    return [(id) self doSomethingWith:aParameter];
}

- (int) doSomethingWith:(void *) aParameter
{
    // The Objective-C function you wanted to call from C++.
    // do work here..
    return 21 ; // half of 42
}
@end

MyCPPClass.cpp

#include "MyCPPClass.h"
#include "MyObject-C-Interface.h"

int MyCPPClass::someMethod (void *objectiveCObject, void *aParameter)
{
    // To invoke an Objective-C method from C++, use
    // the C trampoline function
    return MyObjectDoSomethingWith (objectiveCObject, aParameter);
}

The wrapper function does not need to be in the same .m file as the Objective-C class, but the file that it does exist in needs to be compiled as Objective-C code. The header that declares the wrapper function needs to be included in both CPP and Objective-C code.

(NOTE: if the Objective-C implementation file is given the extension ".m" it will not link under Xcode. The ".mm" extension tells Xcode to expect a combination of Objective-C and C++, i.e., Objective-C++.)


You can implement the above in an Object-Orientented manner by using the PIMPL idiom. The implementation is only slightly different. In short, you place the wrapper functions (declared in "MyObject-C-Interface.h") inside a class with a (private) void pointer to an instance of MyClass.

MyObject-C-Interface.h (PIMPL)

#ifndef __MYOBJECT_C_INTERFACE_H__
#define __MYOBJECT_C_INTERFACE_H__

class MyClassImpl
{
public:
    MyClassImpl ( void );
    ~MyClassImpl( void );

    void init( void );
    int  doSomethingWith( void * aParameter );
    void logMyMessage( char * aCStr );

private:
    void * self;
};

#endif

Notice the wrapper methods no longer require the void pointer to an instance of MyClass; it is now a private member of MyClassImpl. The init method is used to instantiate a MyClass instance;

MyObject.h (PIMPL)

#import "MyObject-C-Interface.h"

@interface MyObject : NSObject
{
    int someVar;
}

- (int)  doSomethingWith:(void *) aParameter;
- (void) logMyMessage:(char *) aCStr;

@end

MyObject.mm (PIMPL)

#import "MyObject.h"

@implementation MyObject

MyClassImpl::MyClassImpl( void )
    : self( NULL )
{   }

MyClassImpl::~MyClassImpl( void )
{
    [(id)self dealloc];
}

void MyClassImpl::init( void )
{    
    self = [[MyObject alloc] init];
}

int MyClassImpl::doSomethingWith( void *aParameter )
{
    return [(id)self doSomethingWith:aParameter];
}

void MyClassImpl::logMyMessage( char *aCStr )
{
    [(id)self doLogMessage:aCStr];
}

- (int) doSomethingWith:(void *) aParameter
{
    int result;

    // ... some code to calculate the result

    return result;
}

- (void) logMyMessage:(char *) aCStr
{
    NSLog( aCStr );
}

@end

Notice that MyClass is instantiated with a call to MyClassImpl::init. You could instantiate MyClass in MyClassImpl's constructor, but that generally isn't a good idea. The MyClass instance is destructed from MyClassImpl's destructor. As with the C-style implementation, the wrapper methods simply defer to the respective methods of MyClass.

MyCPPClass.h (PIMPL)

#ifndef __MYCPP_CLASS_H__
#define __MYCPP_CLASS_H__

class MyClassImpl;

class MyCPPClass
{
    enum { cANSWER_TO_LIFE_THE_UNIVERSE_AND_EVERYTHING = 42 };
public:
    MyCPPClass ( void );
    ~MyCPPClass( void );

    void init( void );
    void doSomethingWithMyClass( void );

private:
    MyClassImpl * _impl;
    int           _myValue;
};

#endif

MyCPPClass.cpp (PIMPL)

#include "MyCPPClass.h"
#include "MyObject-C-Interface.h"

MyCPPClass::MyCPPClass( void )
    : _impl ( NULL )
{   }

void MyCPPClass::init( void )
{
    _impl = new MyClassImpl();
}

MyCPPClass::~MyCPPClass( void )
{
    if ( _impl ) { delete _impl; _impl = NULL; }
}

void MyCPPClass::doSomethingWithMyClass( void )
{
    int result = _impl->doSomethingWith( _myValue );
    if ( result == cANSWER_TO_LIFE_THE_UNIVERSE_AND_EVERYTHING )
    {
        _impl->logMyMessage( "Hello, Arthur!" );
    }
    else
    {
        _impl->logMyMessage( "Don't worry." );
    }
}

You now access calls to MyClass through a private implementation of MyClassImpl. This approach can be advantageous if you were developing a portable application; you could simply swap out the implementation of MyClass with one specific to the other platform ... but honestly, whether this is a better implementation is more a matter of taste and needs.

Sass calculate percent minus px

Sorry for reviving old thread - Compass' stretch with an :after pseudo-selector might suit your purpose - eg. if you want a div to fill width from left to (50% + 10px) of screen you could use (in SASS indented syntax):

.example
    background: red
    +stretch(0, -10px, 0, 0)
    &:after
        +stretch(0, 0, 0, 50%)
        content: ' '
        background: blue

The :after element fills 50% to the right of .example (leaving 50% available for .example's width), then .example is stretched to that width plus 10px.

One-liner if statements, how to convert this if-else-statement

If expression returns a boolean, you can just return the result of it.

Example

 return (a > b)

How to Code Double Quotes via HTML Codes

There really aren't any differences.

&quot; is processed as &#34; which is the decimal equivalent of &x22; which is the ISO 8859-1 equivalent of ".

The only reason you may be against using &quot; is because it was mistakenly omitted from the HTML 3.2 specification.

Otherwise it all boils down to personal preference.

Xcode Simulator: how to remove older unneeded devices?

Run this command in terminal to remove simulators that can't be accessed from the current version of Xcode (8+?) in use on your machine.

xcrun simctl delete unavailable

Also if you're looking to reclaim simulator related space Michael Tsai found that deleting sim logs saved him 30 GB.

~/Library/Logs/CoreSimulator

Convert Text to Date?

For DD-MM-YYYY here is a simple workaround to manage string and dates:

insert the date into the string via DD-MMM-YYYY for example 01-11-2017 -> 01-Nov-2017

U can use the FORMAT(date, "dd-mmm-yyyy") to input dates into a string from the spread sheet.

Later, when you output it from a string, it will not confuse the days and months.

How to suppress scientific notation when printing float values?

This will work for any exponent:

def getExpandedScientificNotation(flt):
    str_vals = str(flt).split('e')
    coef = float(str_vals[0])
    exp = int(str_vals[1])
    return_val = ''
    if int(exp) > 0:
        return_val += str(coef).replace('.', '')
        return_val += ''.join(['0' for _ in range(0, abs(exp - len(str(coef).split('.')[1])))])
    elif int(exp) < 0:
        return_val += '0.'
        return_val += ''.join(['0' for _ in range(0, abs(exp) - 1)])
        return_val += str(coef).replace('.', '')
    return return_val

Different ways of clearing lists

It appears to me that del will give you the memory back, while assigning a new list will make the old one be deleted only when the gc runs.matter.

This may be useful for large lists, but for small list it should be negligible.

Edit: As Algorias, it doesn't matter.

Note that

del old_list[ 0:len(old_list) ]

is equivalent to

del old_list[:]

Laravel Eloquent update just if changes have been made

You're already doing it!

save() will check if something in the model has changed. If it hasn't it won't run a db query.

Here's the relevant part of code in Illuminate\Database\Eloquent\Model@performUpdate:

protected function performUpdate(Builder $query, array $options = [])
{
    $dirty = $this->getDirty();

    if (count($dirty) > 0)
    {
        // runs update query
    }

    return true;
}

The getDirty() method simply compares the current attributes with a copy saved in original when the model is created. This is done in the syncOriginal() method:

public function __construct(array $attributes = array())
{
    $this->bootIfNotBooted();

    $this->syncOriginal();

    $this->fill($attributes);
}

public function syncOriginal()
{
    $this->original = $this->attributes;

    return $this;
}

If you want to check if the model is dirty just call isDirty():

if($product->isDirty()){
    // changes have been made
}

Or if you want to check a certain attribute:

if($product->isDirty('price')){
    // price has changed
}

How to merge many PDF files into a single one?

First, get Pdftk:

sudo apt-get install pdftk

Now, as shown on example page, use

pdftk 1.pdf 2.pdf 3.pdf cat output 123.pdf

for merging pdf files into one.

Extract specific columns from delimited file using Awk

You can use a for-loop to address a field with $i:

ls -l | awk '{for(i=3 ; i<8 ; i++) {printf("%s\t", $i)} print ""}'

Window vs Page vs UserControl for WPF navigation?

  • Window is like Windows.Forms.Form, so just a new window
  • Page is, according to online documentation:

    Encapsulates a page of content that can be navigated to and hosted by Windows Internet Explorer, NavigationWindow, and Frame.

    So you basically use this if going you visualize some HTML content

  • UserControl is for cases when you want to create some reusable component (but not standalone one) to use it in multiple different Windows

How to return only the Date from a SQL Server DateTime datatype

 Convert(nvarchar(10), getdate(), 101) --->  5/12/14

 Convert(nvarchar(12), getdate(), 101) --->  5/12/2014

How to center buttons in Twitter Bootstrap 3?

use text-align: center css property

How to hide columns in an ASP.NET GridView with auto-generated columns?

Try this to hide columns in an ASP.NET GridView with auto-generated columns, both RowDataBound/RowCreated work too.

Protected Sub GridView1_RowDataBound(sender As Object, e As GridViewRowEventArgs) Handles GridView1.RowDataBound

    If e.Row.RowType = DataControlRowType.DataRow Or _
        e.Row.RowType = DataControlRowType.Header Then   // apply to datarow and header 

        e.Row.Cells(e.Row.Cells.Count - 1).Visible = False // last column
        e.Row.Cells(0).Visible = False  // first column

    End If
End Sub

Protected Sub GridView1_RowCreated(sender As Object, e As GridViewRowEventArgs) Handles GridView1.RowCreated

    If e.Row.RowType = DataControlRowType.DataRow Or _
        e.Row.RowType = DataControlRowType.Header Then

        e.Row.Cells(e.Row.Cells.Count - 1).Visible = False
        e.Row.Cells(0).Visible = False

    End If
End Sub

PUT vs. POST in REST

Short Answer:

Simple rule of thumb: Use POST to create, use PUT to update.

Long Answer:

POST:

  • POST is used to send data to server.
  • Useful when the resource's URL is unknown

PUT:

  • PUT is used to transfer state to the server
  • Useful when a resource's URL is known

Longer Answer:

To understand it we need to question why PUT was required, what were the problems PUT was trying to solve that POST couldn't.

From a REST architecture's point of view there is none that matters. We could have lived without PUT as well. But from a client developer's point of view it made his/her life a lot simpler.

Prior to PUT, clients couldn't directly know the URL that the server generated or if all it had generated any or whether the data to be sent to the server is already updated or not. PUT relieved the developer of all these headaches. PUT is idempotent, PUT handles race conditions, and PUT lets the client choose the URL.

Python error: "IndexError: string index out of range"

There were several problems in your code. Here you have a functional version you can analyze (Lets set 'hello' as the target word):

word = 'hello'
so_far = "-" * len(word)       # Create variable so_far to contain the current guess

while word != so_far:          # if still not complete
    print(so_far)
    guess = input('>> ')       # get a char guess

    if guess in word:
        print("\nYes!", guess, "is in the word!")

        new = ""
        for i in range(len(word)):  
            if guess == word[i]:
                new += guess        # fill the position with new value
            else:
                new += so_far[i]    # same value as before
        so_far = new
    else:
        print("try_again")

print('finish')

I tried to write it for py3k with a py2k ide, be careful with errors.

Why catch and rethrow an exception in C#?

A valid reason for rethrowing exceptions can be that you want to add information to the exception, or perhaps wrap the original exception in one of your own making:

public static string SerializeDTO(DTO dto) {
  try {
      XmlSerializer xmlSer = new XmlSerializer(dto.GetType());
      StringWriter sWriter = new StringWriter();
      xmlSer.Serialize(sWriter, dto);
      return sWriter.ToString();
  }
  catch(Exception ex) {
    string message = 
      String.Format("Something went wrong serializing DTO {0}", DTO);
    throw new MyLibraryException(message, ex);
  }
}

How to unbind a listener that is calling event.preventDefault() (using jQuery)?

$('#my_elementtt').click(function(event){
    trigger('click');
});

Call another rest api from my server in Spring-Boot

This website has some nice examples for using spring's RestTemplate. Here is a code example of how it can work to get a simple object:

private static void getEmployees()
{
    final String uri = "http://localhost:8080/springrestexample/employees.xml";

    RestTemplate restTemplate = new RestTemplate();
    String result = restTemplate.getForObject(uri, String.class);

    System.out.println(result);
}

104, 'Connection reset by peer' socket error, or When does closing a socket result in a RST rather than FIN?

Normally, you'd get an RST if you do a close which doesn't linger (i.e. in which data can be discarded by the stack if it hasn't been sent and ACK'd) and a normal FIN if you allow the close to linger (i.e. the close waits for the data in transit to be ACK'd).

Perhaps all you need to do is set your socket to linger so that you remove the race condition between a non lingering close done on the socket and the ACKs arriving?

How do I launch the Android emulator from the command line?

I wrote this simple shell script using Zenity that lets you pick which avd you want to run. If you don't have ANDROID_HOME defined, you can just replace that with the full path to emulator. This would be easy to do with select instead of Zenity also, but I opted for Zenity since I'm running it from the xfce-application menu (though a .desktop-file).

#!/bin/sh

opt=$(zenity --title="Choose AVD" --text="Choose which emulator to start" --list \
                   --column="Devices" --separator="\n" `$ANDROID_HOME/emulator/emulator -list-avds`);

$ANDROID_HOME/emulator/emulator -avd $opt

How to set cookie value with AJAX request?

Basically, ajax request as well as synchronous request sends your document cookies automatically. So, you need to set your cookie to document, not to request. However, your request is cross-domain, and things became more complicated. Basing on this answer, additionally to set document cookie, you should allow its sending to cross-domain environment:

type: "GET",    
url: "http://example.com",
cache: false,
// NO setCookies option available, set cookie to document
//setCookies: "lkfh89asdhjahska7al446dfg5kgfbfgdhfdbfgcvbcbc dfskljvdfhpl",
crossDomain: true,
dataType: 'json',
xhrFields: {
    withCredentials: true
},
success: function (data) {
    alert(data);
});

How to set a JVM TimeZone Properly

Two options that I don’t think were covered in the other answers:

Avoid the need

Whatever you do to set the JVM default time zone, it is very hard to make sure that no one else sets it differently. It can be set at any time without notice from another part of your program or from another program running in the same JVM. So in your time operations be explicit about which time zone you want, and you will always know what you get independently of the JVM setting. Example:

    System.out.println(ZonedDateTime.now(ZoneId.of("Asia/Dushanbe")));

Example output:

2018-10-11T14:59:16.742020+05:00[Asia/Dushanbe]

System.setProperty

For many purposes the following will not be the preferred way, and it can certainly be misused. For “throw away” programs I sometimes find it practical. You can also set a system property from within Java:

    System.setProperty("user.timezone", "Australia/Tasmania");
    System.out.println(ZonedDateTime.now());

This just printed:

2018-10-11T21:03:12.218959+11:00[Australia/Tasmania]

If you want validation of the string you are passing, use:

        System.setProperty("user.timezone", ZoneId.of("Australia/Tasmania").getId());

CSS Flex Box Layout: full-width row and columns

This is copied from above, but condensed slightly and re-written in semantic terms. Note: #Container has display: flex; and flex-direction: column;, while the columns have flex: 3; and flex: 2; (where "One value, unitless number" determines the flex-grow property) per MDN flex docs.

_x000D_
_x000D_
#Container {_x000D_
  display: flex;_x000D_
  flex-direction: column;_x000D_
  height: 600px;_x000D_
  width: 580px;_x000D_
}_x000D_
_x000D_
.Content {_x000D_
  display: flex;_x000D_
  flex: 1;_x000D_
}_x000D_
_x000D_
#Detail {_x000D_
  flex: 3;_x000D_
  background-color: lime;_x000D_
}_x000D_
_x000D_
#ThumbnailContainer {_x000D_
  flex: 2;_x000D_
  background-color: black;_x000D_
}
_x000D_
<div id="Container">_x000D_
  <div class="Content">_x000D_
    <div id="Detail"></div>_x000D_
    <div id="ThumbnailContainer"></div>_x000D_
  </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

reading from app.config file

Try to rebuild your project - It copies the content of App.config to "<YourProjectName.exe>.config" in the build library.

#1071 - Specified key was too long; max key length is 767 bytes

When you hit the limit. Set the following.

  • INNODB utf8 VARCHAR(255)
  • INNODB utf8mb4 VARCHAR(191)

Get Maven artifact version at runtime

If you happen to use Spring Boot you can make use of the BuildProperties class.

Take the following snippet from our OpenAPI configuration class as an example:

@Configuration
@RequiredArgsConstructor // <- lombok
public class OpenApi {

    private final BuildProperties buildProperties; // <- you can also autowire it

    @Bean
    public OpenAPI yourBeautifulAPI() {
        return new OpenAPI().info(new Info()
            .title(buildProperties.getName())
            .description("The description")
            .version(buildProperties.getVersion())
            .license(new License().name("Your company")));
    }
}

POST request not allowed - 405 Not Allowed - nginx, even with headers included

In my case it was POST submission of a json to be processed and get a return value. I cross checked logs of my app server with and without nginx. What i got was my location was not getting appended to proxy_pass url and the version of HTTP protocol version is different.

  • Without nginx: "POST /xxQuery HTTP/1.1" 200 -
  • With nginx: "POST / HTTP/1.0" 405 -

My earlier location block was

location /xxQuery {
    proxy_method POST;
    proxy_pass http://127.0.0.1:xx00/;
    client_max_body_size 10M;
}

I changed it to

location /xxQuery {
    proxy_method POST;
    proxy_http_version 1.1;
    proxy_pass http://127.0.0.1:xx00/xxQuery;
    client_max_body_size 10M;
}

It worked.

Creating and appending text to txt file in VB.NET

Try this:

Dim strFile As String = "yourfile.txt"
Dim fileExists As Boolean = File.Exists(strFile)
Using sw As New StreamWriter(File.Open(strFile, FileMode.OpenOrCreate))
    sw.WriteLine( _
        IIf(fileExists, _
            "Error Message in  Occured at-- " & DateTime.Now, _
            "Start Error Log for today"))
End Using

Displaying all table names in php from MySQL database

The brackets that are commonly used in the mysql documentation for examples should be ommitted in a 'real' query.

It also doesn't appear that you're echoing the result of the mysql query anywhere. mysql_query returns a mysql resource on success. The php manual page also includes instructions on how to load the mysql result resource into an array for echoing and other manipulation.

How to change JAVA.HOME for Eclipse/ANT

Also be sure to set your JAVA_HOME environment variable. In fact, I usually set the JAVA_HOME, then prepend the string "%JAVA_HOME%\bin" to the system's PATH environment variable so that if Java ever gets upgraded or changed, only the JAVA_HOME variable will need to be changed.

And make sure that you close any command prompt windows or open applications that may read your environment variables, as changes to environment variables are normally not noticed until an application is re-launched.

How to get all columns' names for all the tables in MySQL?

On the offchance that it's useful to anyone else, this will give you a comma-delimited list of the columns in each table:

SELECT table_name,GROUP_CONCAT(column_name ORDER BY ordinal_position)
FROM information_schema.columns
WHERE table_schema = DATABASE()
GROUP BY table_name
ORDER BY table_name

Note : When using tables with a high number of columns and/or with long field names, be aware of the group_concat_max_len limit, which can cause the data to get truncated.

jQuery Mobile how to check if button is disabled?

You can use jQuery.is() function along with :disabled selector:

$("#savematerial").is(":disabled")

REST API Authentication

You can use HTTP Basic or Digest Authentication. You can securely authenticate users using SSL on the top of it, however, it slows down the API a little bit.

  • Basic authentication - uses Base64 encoding on username and password
  • Digest authentication - hashes the username and password before sending them over the network.

OAuth is the best it can get. The advantages oAuth gives is a revokable or expirable token. Refer following on how to implement: Working Link from comments: https://www.ida.liu.se/~TDP024/labs/hmacarticle.pdf

Efficient method to generate UUID String in JAVA (UUID.randomUUID().toString() without the dashes)

Dashes don't need to be removed from HTTP request as you can see in URL of this thread. But if you want to prepare well-formed URL without dependency on data you should use URLEncoder.encode( String data, String encoding ) instead of changing standard form of you data. For UUID string representation dashes is normal.

How to copy and paste worksheets between Excel workbooks?

I'm using this code, hope this helps!

Application.ScreenUpdating = False
Application.EnableEvents = False

Dim destination_wb As Workbook
Set destination_wb = Workbooks.Open(DESTINATION_WORKBOOK_NAME)

worksheet_to_copy.Copy Before:=destination_wb.Worksheets(1)
destination_wb.Worksheets(1).Name = worksheet_to_copy.Name
'Add the sheets count to the name to avoid repeated worksheet names error
'& destination_wb.Worksheets.Count


'optional
destination_wb.Worksheets(1).UsedRange.Columns.AutoFit

'I use this to avoid macro errors in destination_wb
Call DeleteAllVBACode(destination_wb)

'Delete source worksheet
Application.DisplayAlerts = False
worksheet_to_copy.Delete
Application.DisplayAlerts = True

destination_wb.Save
destination_wb.Close

Application.EnableEvents = True
Application.ScreenUpdating = True

' From http://www.cpearson.com/Excel/vbe.aspx           

Public Sub DeleteAllVBACode(libro As Workbook)
    Dim VBProj As VBProject
    Dim VBComp As VBComponent
    Dim CodeMod As CodeModule

    Set VBProj = libro.VBProject

    For Each VBComp In VBProj.VBComponents
        If VBComp.Type = vbext_ct_Document Then
            Set CodeMod = VBComp.CodeModule
            With CodeMod
                .DeleteLines 1, .CountOfLines
            End With
        Else
            VBProj.VBComponents.Remove VBComp
        End If
    Next VBComp
End Sub

How to run a command as a specific user in an init script?

On RHEL systems, the /etc/rc.d/init.d/functions script is intended to provide similar to what you want. If you source that at the top of your init script, all of it's functions become available.

The specific function provided to help with this is daemon. If you are intending to use it to start a daemon-like program, a simple usage would be:

daemon --user=username command

If that is too heavy-handed for what you need, there is runuser (see man runuser for full info; some versions may need -u prior to the username):

/sbin/runuser username -s /bin/bash -c "command(s) to run as user username"

How to make a GUI for bash scripts?

Please, take a look at my library: http://sites.google.com/site/easybashgui

It is intended to handle, with the same commands set, indifferently all four big tools "kdialog", "Xdialog", "cdialog" and "zenity", depending if X is running or not, if D.E. is KDE or Gnome or other. There are 15 different functions ( among them there are two called "progress" and "adjust" )...

Bye :-)

JQuery .hasClass for multiple values in an if statement

For anyone wondering about some of the different performance aspects with all of these different options, I've created a jsperf case here: jsperf

In short, using element.hasClass('class') is the fastest.

Next best bet is using elem.hasClass('classA') || elem.hasClass('classB'). A note on this one: order matters! If the class 'classA' is more likely to be found, list it first! OR condition statements return as soon as one of them is met.

The worst performance by far was using element.is('.class').

Also listed in the jsperf is CyberMonk's function, and Kolja's solution.

Get names of all files from a folder with Ruby

In addition to the suggestions in this thread, I wanted to mention that if you need to return dot files as well (.gitignore, etc), with Dir.glob you would need to include a flag as so: Dir.glob("/path/to/dir/*", File::FNM_DOTMATCH) By default, Dir.entries includes dot files, as well as current a parent directories.

For anyone interested, I was curious how the answers here compared to each other in execution time, here was the results against deeply nested hierarchy. The first three results are non-recursive:

       user     system      total        real
Dir[*]: (34900 files stepped over 100 iterations)
  0.110729   0.139060   0.249789 (  0.249961)
Dir.glob(*): (34900 files stepped over 100 iterations)
  0.112104   0.142498   0.254602 (  0.254902)
Dir.entries(): (35600 files stepped over 100 iterations)
  0.142441   0.149306   0.291747 (  0.291998)
Dir[**/*]: (2211600 files stepped over 100 iterations)
  9.399860  15.802976  25.202836 ( 25.250166)
Dir.glob(**/*): (2211600 files stepped over 100 iterations)
  9.335318  15.657782  24.993100 ( 25.006243)
Dir.entries() recursive walk: (2705500 files stepped over 100 iterations)
 14.653018  18.602017  33.255035 ( 33.268056)
Dir.glob(**/*, File::FNM_DOTMATCH): (2705500 files stepped over 100 iterations)
 12.178823  19.577409  31.756232 ( 31.767093)

These were generated with the following benchmarking script:

require 'benchmark'
base_dir = "/path/to/dir/"
n = 100
Benchmark.bm do |x|
  x.report("Dir[*]:") do
    i = 0
    n.times do
      i = i + Dir["#{base_dir}*"].select {|f| !File.directory? f}.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
  x.report("Dir.glob(*):") do
    i = 0
    n.times do
      i = i + Dir.glob("#{base_dir}/*").select {|f| !File.directory? f}.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
  x.report("Dir.entries():") do
    i = 0
    n.times do
      i = i + Dir.entries(base_dir).select {|f| !File.directory? File.join(base_dir, f)}.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
  x.report("Dir[**/*]:") do
    i = 0
    n.times do
      i = i + Dir["#{base_dir}**/*"].select {|f| !File.directory? f}.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
  x.report("Dir.glob(**/*):") do
    i = 0
    n.times do
      i = i + Dir.glob("#{base_dir}**/*").select {|f| !File.directory? f}.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
  x.report("Dir.entries() recursive walk:") do
    i = 0
    n.times do
      def walk_dir(dir, result)
        Dir.entries(dir).each do |file|
          next if file == ".." || file == "."

          path = File.join(dir, file)
          if Dir.exist?(path)
            walk_dir(path, result)
          else
            result << file
          end
        end
      end
      result = Array.new
      walk_dir(base_dir, result)
      i = i + result.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
  x.report("Dir.glob(**/*, File::FNM_DOTMATCH):") do
    i = 0
    n.times do
      i = i + Dir.glob("#{base_dir}**/*", File::FNM_DOTMATCH).select {|f| !File.directory? f}.length
    end
    puts " (#{i} files stepped over #{n} iterations)"
  end
end

The differences in file counts are due to Dir.entries including hidden files by default. Dir.entries ended up taking a bit longer in this case due to needing to rebuild the absolute path of the file to determine if a file was a directory, but even without that it was still taking consistently longer than the other options in the recursive case. This was all using ruby 2.5.1 on OSX.

Resolving LNK4098: defaultlib 'MSVCRT' conflicts with

There are 4 versions of the CRT link libraries present in vc\lib:

  • libcmt.lib: static CRT link library for a release build (/MT)
  • libcmtd.lib: static CRT link library for a debug build (/MTd)
  • msvcrt.lib: import library for the release DLL version of the CRT (/MD)
  • msvcrtd.lib: import library for the debug DLL version of the CRT (/MDd)

Look at the linker options, Project + Properties, Linker, Command Line. Note how these libraries are not mentioned here. The linker automatically figures out what /M switch was used by the compiler and which .lib should be linked through a #pragma comment directive. Kinda important, you'd get horrible link errors and hard to diagnose runtime errors if there was a mismatch between the /M option and the .lib you link with.

You'll see the error message you quoted when the linker is told both to link to msvcrt.lib and libcmt.lib. Which will happen if you link code that was compiled with /MT with code that was linked with /MD. There can be only one version of the CRT.

/NODEFAULTLIB tells the linker to ignore the #pragma comment directive that was generated from the /MT compiled code. This might work, although a slew of other linker errors is not uncommon. Things like errno, which is a extern int in the static CRT version but macro-ed to a function in the DLL version. Many others like that.

Well, fix this problem the Right Way, find the .obj or .lib file that you are linking that was compiled with the wrong /M option. If you have no clue then you could find it by grepping the .obj/.lib files for "/MT"

Btw: the Windows executables (like version.dll) have their own CRT version to get their job done. It is located in c:\windows\system32, you cannot reliably use it for your own programs, its CRT headers are not available anywhere. The CRT DLL used by your program has a different name (like msvcrt90.dll).

showing that a date is greater than current date

In sql server, you can do

SELECT *
FROM table t
WHERE t.date > DATEADD(dd,90,now())

PHP Fatal error: Class 'PDO' not found

I had to run the following on AWS EC2 Linux instance (PHP Version 7.3):

sudo yum install php73-php-pdo php73-php-mysqlnd

Could not create the Java virtual machine

Just be careful. You will get this message if you try to enter a command that doesn't exist like this

/usr/bin/java -v

R: "Unary operator error" from multiline ggplot2 command

This is a well-known nuisance when posting multiline commands in R. (You can get different behavior when you source() a script to when you copy-and-paste the lines, both with multiline and comments)

Rule: always put the dangling '+' at the end of a line so R knows the command is unfinished:

ggplot(...) + geom_whatever1(...) +
  geom_whatever2(...) +
  stat_whatever3(...) +
  geom_title(...) + scale_y_log10(...)

Don't put the dangling '+' at the start of the line, since that tickles the error:

Error in "+ geom_whatever2(...) invalid argument to unary operator"

And obviously don't put dangling '+' at both end and start since that's a syntax error.

So, learn a habit of being consistent: always put '+' at end-of-line.

cf. answer to "Split code over multiple lines in an R script"

What does file:///android_asset/www/index.html mean?

If someone uses AndroidStudio make sure that the assets folder is placed in

  1. app/src/main/assets

    directory.

Loop through all the files with a specific extension

I agree withe the other answers regarding the correct way to loop through the files. However the OP asked:

The code above doesn't work, do you know why?

Yes!

An excellent article What is the difference between test, [ and [[ ?] explains in detail that among other differences, you cannot use expression matching or pattern matching within the test command (which is shorthand for [ )


Feature            new test [[    old test [           Example

Pattern matching    = (or ==)    (not available)    [[ $name = a* ]] || echo "name does not start with an 'a': $name"

Regular Expression     =~        (not available)    [[ $(date) =~ ^Fri\ ...\ 13 ]] && echo "It's Friday the 13th!"
matching

So this is the reason your script fails. If the OP is interested in an answer with the [[ syntax (which has the disadvantage of not being supported on as many platforms as the [ command), I would be happy to edit my answer to include it.

EDIT: Any protips for how to format the data in the answer as a table would be helpful!

Selenium Webdriver: Entering text into text field

I had a case where I was entering text into a field after which the text would be removed automatically. Turned out it was due to some site functionality where you had to press the enter key after entering the text into the field. So, after sending your barcode text with sendKeys method, send 'enter' directly after it. Note that you will have to import the selenium Keys class. See my code below.

import org.openqa.selenium.Keys;

String barcode="0000000047166";
WebElement element_enter = driver.findElement(By.xpath("//*[@id='div-barcode']"));
element_enter.findElement(By.xpath("your xpath")).sendKeys(barcode);

element_enter.sendKeys(Keys.RETURN); // this will result in the return key being pressed upon the text field

I hope it helps..

Android ADB devices unauthorized

Try deleting the adbkey file from C/.android folder

and then run the commands as mentioned above i.e.

adb kill-server, adb start-server and adb devices

.

Installing SciPy and NumPy using pip

Since the previous instructions for installing with yum are broken here are the updated instructions for installing on something like fedora. I've tested this on "Amazon Linux AMI 2016.03"

sudo yum install atlas-devel lapack-devel blas-devel libgfortran
pip install scipy

CSS Div width percentage and padding without breaking layout

You can also use the CSS calc() function to subtract the width of your padding from the percentage of your container's width.

An example:

width: calc((100%) - (32px))

Just be sure to make the subtracted width equal to the total padding, not just one half. If you pad both sides of the inner div with 16px, then you should subtract 32px from the final width, assuming that the example below is what you want to achieve.

_x000D_
_x000D_
.outer {_x000D_
  width: 200px;_x000D_
  height: 120px;_x000D_
  background-color: black;_x000D_
}_x000D_
_x000D_
.inner {_x000D_
  height: 40px;_x000D_
  top: 30px;_x000D_
  position: relative;_x000D_
  padding: 16px;_x000D_
  background-color: teal;_x000D_
}_x000D_
_x000D_
#inner-1 {_x000D_
  width: 100%;_x000D_
}_x000D_
_x000D_
#inner-2 {_x000D_
  width: calc((100%) - (32px));_x000D_
}
_x000D_
<div class="outer" id="outer-1">_x000D_
  <div class="inner" id="inner-1"> width of 100% </div>_x000D_
</div>_x000D_
_x000D_
<br>_x000D_
<br>_x000D_
_x000D_
<div class="outer" id="outer-2">_x000D_
  <div class="inner" id="inner-2"> width of 100% - 16px </div>_x000D_
</div>
_x000D_
_x000D_
_x000D_

What are the date formats available in SimpleDateFormat class?

Let me throw out some example code that I got from http://www3.ntu.edu.sg/home/ehchua/programming/java/DateTimeCalendar.html Then you can play around with different options until you understand it.

import java.text.SimpleDateFormat;
import java.util.Date;

public class DateTest {
   public static void main(String[] args) {
       Date now = new Date();

       //This is just Date's toString method and doesn't involve SimpleDateFormat
       System.out.println("toString(): " + now);  // dow mon dd hh:mm:ss zzz yyyy
       //Shows  "Mon Oct 08 08:17:06 EDT 2012"

       SimpleDateFormat dateFormatter = new SimpleDateFormat("E, y-M-d 'at' h:m:s a z");
       System.out.println("Format 1:   " + dateFormatter.format(now));
       // Shows  "Mon, 2012-10-8 at 8:17:6 AM EDT"

       dateFormatter = new SimpleDateFormat("E yyyy.MM.dd 'at' hh:mm:ss a zzz");
       System.out.println("Format 2:   " + dateFormatter.format(now));
       // Shows  "Mon 2012.10.08 at 08:17:06 AM EDT"

       dateFormatter = new SimpleDateFormat("EEEE, MMMM d, yyyy");
       System.out.println("Format 3:   " + dateFormatter.format(now));
       // Shows  "Monday, October 8, 2012"

       // SimpleDateFormat can be used to control the date/time display format:
       //   E (day of week): 3E or fewer (in text xxx), >3E (in full text)
       //   M (month): M (in number), MM (in number with leading zero)
       //              3M: (in text xxx), >3M: (in full text full)
       //   h (hour): h, hh (with leading zero)
       //   m (minute)
       //   s (second)
       //   a (AM/PM)
       //   H (hour in 0 to 23)
       //   z (time zone)
       //  (there may be more listed under the API - I didn't check)

   }

}

Good luck!

Frequency table for a single variable

The answer provided by @DSM is simple and straightforward, but I thought I'd add my own input to this question. If you look at the code for pandas.value_counts, you'll see that there is a lot going on.

If you need to calculate the frequency of many series, this could take a while. A faster implementation would be to use numpy.unique with return_counts = True

Here is an example:

import pandas as pd
import numpy as np

my_series = pd.Series([1,2,2,3,3,3])

print(my_series.value_counts())
3    3
2    2
1    1
dtype: int64

Notice here that the item returned is a pandas.Series

In comparison, numpy.unique returns a tuple with two items, the unique values and the counts.

vals, counts = np.unique(my_series, return_counts=True)
print(vals, counts)
[1 2 3] [1 2 3]

You can then combine these into a dictionary:

results = dict(zip(vals, counts))
print(results)
{1: 1, 2: 2, 3: 3}

And then into a pandas.Series

print(pd.Series(results))
1    1
2    2
3    3
dtype: int64

How to create a fix size list in python?

Python has nothing built-in to support this. Do you really need to optimize it so much as I don't think that appending will add that much overhead.

However, you can do something like l = [None] * 1000.

Alternatively, you could use a generator.

module.exports vs. export default in Node.js and ES6

Felix Kling did a great comparison on those two, for anyone wondering how to do an export default alongside named exports with module.exports in nodejs

module.exports = new DAO()
module.exports.initDAO = initDAO // append other functions as named export

// now you have
let DAO = require('_/helpers/DAO');
// DAO by default is exported class or function
DAO.initDAO()

Get gateway ip address in android

Go to terminal

$ adb -s UDID shell
$ ip addr | grep inet 
or
$ netcfg | grep inet

How to have EditText with border in Android Lollipop

A quick and dirty solution I have used is to place the EditText inside of a FrameLayout. The margins of the EditText control the thickness of the border and the border color is determined by the background color of the FrameLayout.

Example:

<FrameLayout
    android:id="@+id/frameLayout"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:background="#000000">

    <EditText
        android:id="@+id/editText"
        android:layout_width="wrap_content"
        android:layout_height="wrap_content"
        android:layout_margin="3dp"
        android:background="@android:color/white"
        android:ems="10"
        android:inputType="text"
        android:textSize="24sp" />
</FrameLayout>

But I would recommend, and the vast majority of the time I do, drawables for borders. Elite's answer is what I would go for in that case.

How do I configure modprobe to find my module?

Follow following steps:

  1. Copy hello.ko to /lib/modules/'uname-r'/misc/
  2. Add misc/hello.ko entry in /lib/modules/'uname-r'/modules.dep
  3. sudo depmod
  4. sudo modprobe hello

modprobe will check modules.dep file for any dependency.

ImportError: No module named pandas

You're missing a few (not terribly clear) steps. Pandas is distributed through pip as a wheel, which means you need to do:

pip install wheel
pip install pandas

You're probably going to run into other issues after this - it looks like you're installing on Windows which isn't the most friendly of targets for numpy/scipy/pandas. Alternatively, you could pickup a binary installer from here.

You also had an error installing numpy. Like before, I recommend grabbing a binary installer for this, as it's not a simple process. However, you can resolve your current error by installing this package from Microsoft.

While it's completely possible to get a perfect environment setup on Windows, I have found the quality-of-life for a Python dev is vastly improved by setting up a debian VM. Especially with the scientific packages, you will run into many cases like this.

How to keep two folders automatically synchronized?

I use this free program to synchronize local files and directories: https://github.com/Fitus/Zaloha.sh. The repository contains a simple demo as well.

The good point: It is a bash shell script (one file only). Not a black box like other programs. Documentation is there as well. Also, with some technical talents, you can "bend" and "integrate" it to create the final solution you like.

Getting each individual digit from a whole integer

This solution gives correct results over the entire range [0,UINT_MAX] without requiring digits to be buffered.

It also works for wider types or signed types (with positive values) with appropriate type changes.

This kind of approach is particularly useful on tiny environments (e.g. Arduino bootloader) because it doesn't end up pulling in all the printf() bloat (when printf() isn't used for demo output) and uses very little RAM. You can get a look at value just by blinking a single led :)

#include <limits.h>
#include <stdio.h>

int
main (void)
{
  unsigned int score = 42;   // Works for score in [0, UINT_MAX]

  printf ("score via printf:     %u\n", score);   // For validation

  printf ("score digit by digit: ");
  unsigned int div = 1;
  unsigned int digit_count = 1;
  while ( div <= score / 10 ) {
    digit_count++;
    div *= 10;
  }
  while ( digit_count > 0 ) {
    printf ("%d", score / div);
    score %= div;
    div /= 10;
    digit_count--;
  }
  printf ("\n");

  return 0;
}

dropping infinite values from dataframes in pandas?

Use (fast and simple):

df = df[np.isfinite(df).all(1)]

This answer is based on DougR's answer in an other question. Here an example code:

import pandas as pd
import numpy as np
df=pd.DataFrame([1,2,3,np.nan,4,np.inf,5,-np.inf,6])
print('Input:\n',df,sep='')
df = df[np.isfinite(df).all(1)]
print('\nDropped:\n',df,sep='')

Result:

Input:
    0
0  1.0000
1  2.0000
2  3.0000
3     NaN
4  4.0000
5     inf
6  5.0000
7    -inf
8  6.0000

Dropped:
     0
0  1.0
1  2.0
2  3.0
4  4.0
6  5.0
8  6.0

Delete from two tables in one query

Try this..

DELETE a.*, b.*  
FROM table1 as a, table2 as b  
WHERE a.id=[Your value here] and b.id=[Your value here]

I let id as a sample column.

Glad this helps. :)

Prevent HTML5 video from being downloaded (right-click saved)?

Here's what I did:

_x000D_
_x000D_
function noRightClick() {_x000D_
      alert("You cannot save this video for copyright reasons. Sorry about that.");_x000D_
}
_x000D_
    <body oncontextmenu="noRightClick();">_x000D_
    <video>_x000D_
    <source src="http://calumchilds.com/videos/big_buck_bunny.mp4" type="video/mp4">_x000D_
    </video>_x000D_
    </body>
_x000D_
_x000D_
_x000D_ This also works for images, text and pretty much anything. However, you can still access the "Inspect" and the "View source" tool through keyboard shortcuts. (As the answer at the top says, you can't stop it entirely.) But you can try to put barriers up to stop them.

How to create a GUID/UUID using iOS

Reviewing the Apple Developer documentation I found the CFUUID object is available on the iPhone OS 2.0 and later.

Find an element in DOM based on an attribute value

We can use attribute selector in DOM by using document.querySelector() and document.querySelectorAll() methods.

for yours:

document.querySelector("[myAttribute='aValue']");

and by using querySelectorAll():

document.querySelectorAll("[myAttribute='aValue']");

In querySelector() and querySelectorAll() methods we can select objects as we select in "CSS".

More about "CSS" attribute selectors in https://developer.mozilla.org/en-US/docs/Web/CSS/Attribute_selectors

Convert string to Date in java

This code will help you to make a result like FEB 17 20:49 .

    String myTimestamp="2014/02/17 20:49";

    SimpleDateFormat form = new SimpleDateFormat("yyyy/MM/dd HH:mm");
    Date date = null;
    Date time = null;
    try 
    {
        date = form.parse(myTimestamp);
        time = new Date(myTimestamp);
        SimpleDateFormat postFormater = new SimpleDateFormat("MMM dd");
        SimpleDateFormat sdf = new SimpleDateFormat("HH:mm");
        String newDateStr = postFormater.format(date).toUpperCase();
        String newTimeStr = sdf.format(time);
        System.out.println("Date  : "+newDateStr);
        System.out.println("Time  : "+newTimeStr);
    }
    catch (Exception e) 
    {
        e.printStackTrace();
    }

Result :

Date : FEB 17

Time : 20:49

Creating an empty file in C#

Using just File.Create will leave the file open, which probably isn't what you want.

You could use:

using (File.Create(filename)) ;

That looks slightly odd, mind you. You could use braces instead:

using (File.Create(filename)) {}

Or just call Dispose directly:

File.Create(filename).Dispose();

Either way, if you're going to use this in more than one place you should probably consider wrapping it in a helper method, e.g.

public static void CreateEmptyFile(string filename)
{
    File.Create(filename).Dispose();
}

Note that calling Dispose directly instead of using a using statement doesn't really make much difference here as far as I can tell - the only way it could make a difference is if the thread were aborted between the call to File.Create and the call to Dispose. If that race condition exists, I suspect it would also exist in the using version, if the thread were aborted at the very end of the File.Create method, just before the value was returned...

How to concatenate properties from multiple JavaScript objects

To merge a dynamic number of objects, we can use Object.assign with spread syntax.

const mergeObjs = (...objs) => Object.assign({}, ...objs);

The above function accepts any number of objects, merging all of their properties into a new object with properties from later objects overwriting those from previous objects.

Demo:

_x000D_
_x000D_
const mergeObjs = (...objs) => Object.assign({}, ...objs);
const a = {prop: 1, prop2: '2'},
      b = {prop3: 3, prop4: [1,2,3,4]}
      c = {prop5: 5},
      d = {prop6: true, prop7: -1},
      e = {prop1: 2};
const abcd = mergeObjs(a,b,c,d);
console.log("Merged a,b,c,d:", abcd);
const abd = mergeObjs(a,b,d);
console.log("Merged a,b,d:", abd);
const ae = mergeObjs(a,e);//prop1 from e will overwrite prop1 from a
console.log("Merged a,e:", ae);
_x000D_
_x000D_
_x000D_

To merge an array of objects, a similar method may be applied.

const mergeArrayOfObjs = arr => Object.assign({}, ...arr);

Demo:

_x000D_
_x000D_
const mergeArrayOfObjs = arr => Object.assign({}, ...arr);
const arr = [
  {a: 1, b: 2},
  {c:1, d:3},
  {abcd: [1,2,3,4], d: 4}
];
const merged = mergeArrayOfObjs(arr);
console.log(merged);
_x000D_
_x000D_
_x000D_

How to set selectedIndex of select element using display text?

<script type="text/javascript">
     function SelectAnimal(){
         //Set selected option of Animals based on AnimalToFind value...
         var animalTofind = document.getElementById('AnimalToFind');
         var selection = document.getElementById('Animals');

        // select element
        for(var i=0;i<selection.options.length;i++){
            if (selection.options[i].innerHTML == animalTofind.value) {
                selection.selectedIndex = i;
                break;
            }
        }
     }
</script>

setting the selectedIndex property of the select tag will choose the correct item. it is a good idea of instead of comparing the two values (options innerHTML && animal value) you can use the indexOf() method or regular expression to select the correct option despite casing or presense of spaces

selection.options[i].innerHTML.indexOf(animalTofind.value) != -1;

or using .match(/regular expression/)

How to identify which columns are not "NA" per row in a matrix?

Try:

which( !is.na(p), arr.ind=TRUE)

Which I think is just as informative and probably more useful than the output you specified, But if you really wanted the list version, then this could be used:

> apply(p, 1, function(x) which(!is.na(x)) )
[[1]]
[1] 2 3

[[2]]
[1] 4 7

[[3]]
integer(0)

[[4]]
[1] 5

[[5]]
integer(0)

Or even with smushing together with paste:

lapply(apply(p, 1, function(x) which(!is.na(x)) ) , paste, collapse=", ")

The output from which function the suggested method delivers the row and column of non-zero (TRUE) locations of logical tests:

> which( !is.na(p), arr.ind=TRUE)
     row col
[1,]   1   2
[2,]   1   3
[3,]   2   4
[4,]   4   5
[5,]   2   7

Without the arr.ind parameter set to non-default TRUE, you only get the "vector location" determined using the column major ordering the R has as its convention. R-matrices are just "folded vectors".

> which( !is.na(p) )
[1]  6 11 17 24 32

How to "log in" to a website using Python's Requests module?

Find out the name of the inputs used on the websites form for usernames <...name=username.../> and passwords <...name=password../> and replace them in the script below. Also replace the URL to point at the desired site to log into.

login.py

#!/usr/bin/env python

import requests
from requests.packages.urllib3.exceptions import InsecureRequestWarning
requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
payload = { 'username': '[email protected]', 'password': 'blahblahsecretpassw0rd' }
url = 'https://website.com/login.html'
requests.post(url, data=payload, verify=False)

The use of disable_warnings(InsecureRequestWarning) will silence any output from the script when trying to log into sites with unverified SSL certificates.

Extra:

To run this script from the command line on a UNIX based system place it in a directory, i.e. home/scripts and add this directory to your path in ~/.bash_profile or a similar file used by the terminal.

# Custom scripts
export CUSTOM_SCRIPTS=home/scripts
export PATH=$CUSTOM_SCRIPTS:$PATH

Then create a link to this python script inside home/scripts/login.py

ln -s ~/home/scripts/login.py ~/home/scripts/login

Close your terminal, start a new one, run login

Exception: Can't bind to 'ngFor' since it isn't a known native property

Also don't try to use pure TypeScript in this... I wanted to more correspond to for usage and use *ngFor="const filter of filters" and got the ngFor not a known property error. Just replacing const by let is working.

As @alexander-abakumov said for the of replaced by in.

How to get element by innerText

While it's possible to get by the inner text, I think you are heading the wrong way. Is that inner string dynamically generated? If so, you can give the tag a class or -- better yet -- ID when the text goes in there. If it's static, then it's even easier.

Git push requires username and password

Permanently authenticating with Git repositories

Run the following command to enable credential caching:

$ git config credential.helper store
$ git push https://github.com/owner/repo.git

Username for 'https://github.com': <USERNAME>
Password for 'https://[email protected]': <PASSWORD>

You should also specify caching expire,

git config --global credential.helper 'cache --timeout 7200'

After enabling credential caching, it will be cached for 7200 seconds (2 hour).

Using an integer as a key in an associative array in JavaScript

As people say, JavaScript will convert a string of number to integer, so it is not possible to use directly on an associative array, but objects will work for you in similar way I think.

You can create your object:

var object = {};

And add the values as array works:

object[1] = value;
object[2] = value;

This will give you:

{
  '1': value,
  '2': value
}

After that you can access it like an array in other languages getting the key:

for(key in object)
{
   value = object[key] ;
}

I have tested and works.

How to use nan and inf in C?

I usually use

#define INFINITY (1e999)

or

const double INFINITY = 1e999

which works at least in IEEE 754 contexts because the highest representable double value is roughly 1e308. 1e309 would work just as well, as would 1e99999, but three nines is sufficient and memorable. Since this is either a double literal (in the #define case) or an actual Inf value, it will remain infinite even if you're using 128-bit (“long double”) floats.

Streaming video from Android camera to server

Took me some time, but I finally manage do make an app that does just that. Check out the google code page if you're interested: http://code.google.com/p/spydroid-ipcamera/ I added loads of comments in my code (mainly, look at CameraStreamer.java), so it should be pretty self-explanatory. The hard part was actually to understand the RFC 3984 and implement a proper algorithm for the packetization process. (This algorithm actually turns the mpeg4/h.264 stream produced by the MediaRecorder into a nice rtp stream, according to the rfc)

Bye

How can I use a JavaScript variable as a PHP variable?

<script type="text/javascript">
var jvalue = 'this is javascript value';

<?php $abc = "<script>document.write(jvalue)</script>"?>   
</script>
<?php echo  'php_'.$abc;?>

How can I add a variable to console.log?

When using ES6 you can also do this:

var name = prompt("what is your name?");
console.log(`story ${name} story`);

Note: You need to use backticks `` instead of "" or '' to do it like this.

Pandas: Creating DataFrame from Series

Here is how to create a DataFrame where each series is a row.

For a single Series (resulting in a single-row DataFrame):

series = pd.Series([1,2], index=['a','b'])
df = pd.DataFrame([series])

For multiple series with identical indices:

cols = ['a','b']
list_of_series = [pd.Series([1,2],index=cols), pd.Series([3,4],index=cols)]
df = pd.DataFrame(list_of_series, columns=cols)

For multiple series with possibly different indices:

list_of_series = [pd.Series([1,2],index=['a','b']), pd.Series([3,4],index=['a','c'])]
df = pd.concat(list_of_series, axis=1).transpose()

To create a DataFrame where each series is a column, see the answers by others. Alternatively, one can create a DataFrame where each series is a row, as above, and then use df.transpose(). However, the latter approach is inefficient if the columns have different data types.

Docker is in volume in use, but there aren't any Docker containers

You can use these functions to brutally remove everything Docker related:

removecontainers() {
    docker stop $(docker ps -aq)
    docker rm $(docker ps -aq)
}

armageddon() {
    removecontainers
    docker network prune -f
    docker rmi -f $(docker images --filter dangling=true -qa)
    docker volume rm $(docker volume ls --filter dangling=true -q)
    docker rmi -f $(docker images -qa)
}

You can add those to your ~/Xrc file, where X is your shell interpreter (~/.bashrc if you're using bash) file and reload them via executing source ~/Xrc. Also, you can just copy paste them to the console and afterwards (regardless the option you took before to get the functions ready) just run:

armageddon

It's also useful for just general Docker clean up. Have in mind that this will also remove your images, not only your containers (either running or not) and your volumes of any kind.

best OCR (Optical character recognition) example in android

Like you I also faced many problems implementing OCR in Android, but after much Googling I found the solution, and it surely is the best example of OCR.

Let me explain using step-by-step guidance.

First, download the source code from https://github.com/rmtheis/tess-two.

Import all three projects. After importing you will get an error. To solve the error you have to create a res folder in the tess-two project

enter image description here

First, just create res folder in tess-two by tess-two->RightClick->new Folder->Name it "res"

After doing this in all three project the error should be gone.

Now download the source code from https://github.com/rmtheis/android-ocr, here you will get best example.

Now you just need to import it into your workspace, but first you have to download android-ndk from this site:

http://developer.android.com/tools/sdk/ndk/index.html i have windows 7 - 32 bit PC so I have download http://dl.google.com/android/ndk/android-ndk-r9-windows-x86.zip this file

Now extract it suppose I have extract it into E:\Software\android-ndk-r9 so I will set this path on Environment Variable

Right Click on MyComputer->Property->Advance-System-Settings->Advance->Environment Variable-> find PATH on second below Box and set like path like below picture

enter image description here

done it

Now open cmd and go to on D:\Android Workspace\tess-two like below

enter image description here

If you have successfully set up environment variable of NDK then just type ndk-build just like above picture than enter you will not get any kind of error and all file will be compiled successfully:

Now download other source code also from https://github.com/rmtheis/tess-two , and extract and import it and give it name OCRTest, like in my PC which is in D:\Android Workspace\OCRTest

enter image description here

Import test-two in this and run OCRTest and run it; you will get the best example of OCR.

Visual Studio 2017: Display method references

For anyone who is looking to enable this on the Mac version, it is not available. Developers of Visual Studio stated they will include in their roadmap.

Delete a single record from Entity Framework?

More generic approuch

public virtual void Delete<T>(int id) where T : BaseEntity, new()
{
    T instance = Activator.CreateInstance<T>();
    instance.Id = id;
    if (dbContext.Entry<T>(entity).State == EntityState.Detached)
    {
        dbContext.Set<T>().Attach(entity);
    }

    dbContext.Set<T>().Remove(entity);
}

DynamoDB vs MongoDB NoSQL

Short answer: Start with SQL and add NoSQL only when/if needed. (unless you don't need anything beyond very simple queries)

My personal experience: I haven't used MongoDB for queries but as of April 2015 DynamoDB is still very crippled when it comes to anything beyond the most basic key/value queries. I love it for the basic stuff but if you want query language then look to a real SQL database solution.

In DynamoDB you can query on a hash or on a hash and range key, and you can have multiple secondary global indexes. I'm doing queries on a single table with 4 possible filter parameters and sorting the results, this is supported (barely) through the use of the global secondary indexes with filter expressions. The problem comes in when you try to get the total results matching the filter, you can't just search for the first 10 items matching the filter, but rather it checks 10 items and you may get 0 valid results forcing you to keep re-scanning from the continue key - pain in the neck and consumes too much of your table read quota for a simple scenario.

To be specific about the limit problem with filters in the query, this is from the docs (http://docs.aws.amazon.com/amazondynamodb/latest/developerguide/QueryAndScan.html#ScanQueryLimit):

In a response, DynamoDB returns all the matching results within
the scope of the Limit value. For example, if you issue a Query 
or a Scan request with a Limit value of 6 and without a filter
expression, the operation returns the first six items in the 
table that match the request parameters. If you also supply a
FilterExpression, the operation returns the items within the 
first six items in the table that match the filter requirements.

My conclusion is that queries involving FilterExpressions are only usable on very rare occasions and are not scalable because each query can easily read most or all of your of your table which consumes far too many DynamoDB read units. Once you use too many read units you'll get throttled and see poor performance.

Expert opinion: In the AWS summit on Apr 9, 2015 Brett Hollman, Manager, Solutions Architecture, AWS in his talk on scalling to your first 10 million users advocates starting with a SQL database and then using NoSQL only when and if it makes sense. Because sooner or later you'll probably need a SQL server somewhere in your stack. His slides are here: http://www.slideshare.net/AmazonWebServices/deep-dive-scaling-up-to-your-first-10-million-users See slide 28.

TypeError: 'bool' object is not callable

Actually you can fix it with following steps -

  1. Do cls.__dict__
  2. This will give you dictionary format output which will contain {'isFilled':True} or {'isFilled':False} depending upon what you have set.
  3. Delete this entry - del cls.__dict__['isFilled']
  4. You will be able to call the method now.

In this case, we delete the entry which overrides the method as mentioned by BrenBarn.

How do I automatically scroll to the bottom of a multiline text box?

I use a function for this :

private void Log (string s) {
    TB1.AppendText(Environment.NewLine + s);
    TB1.ScrollToCaret();
}

CREATE TABLE IF NOT EXISTS equivalent in SQL Server

if not exists (select * from sysobjects where name='cars' and xtype='U')
    create table cars (
        Name varchar(64) not null
    )
go

The above will create a table called cars if the table does not already exist.

CSS to line break before/after a particular `inline-block` item

A better solution is to use -webkit-columns:2;

http://jsfiddle.net/YMN7U/889/

 ul { margin:0.5em auto;
-webkit-columns:2;
}

how to specify local modules as npm package dependencies

At work we have a common library that is used by a few different projects all in a single repository. Originally we used the published (private) version (npm install --save rp-utils) but that lead to a lot of needless version updates as we developed. The library lives in a sister directory to the applications and we are able to use a relative path instead of a version. Instead of "rp-utils": "^1.3.34" in package.json it now is:

{ 
  "dependencies": { ...
    "rp-utils": "../rp-utils",
   ...

the rp-utils directory contains a publishable npm package

HRESULT: 0x80040154 (REGDB_E_CLASSNOTREG))

Just looking at the message it sounds like one or more of the components that you reference, or one or more of their dependencies is not registered properly.

If you know which component it is you can use regsvr32.exe to register it, just open a command prompt, go to the directory where the component is and type regsvr32 filename.dll (assuming it's a dll), if it works, try to run the code again otherwise come back here with the error.

If you don't know which component it is, try re-installing/repairing the GIS software (I assume you've installed some GIS software that includes the component you're trying to use).

Java FileReader encoding issue

For another as Latin languages for example Cyrillic you can use something like this:

FileReader fr = new FileReader("src/text.txt", StandardCharsets.UTF_8);

and be sure that your .txt file is saved with UTF-8 (but not as default ANSI) format. Cheers!

Is there an embeddable Webkit component for Windows / C# development?

Berkelium is a C++ tool for making chrome embeddable.

AwesomiumDotNet is a wrapper around both Berkelium and Awesomium

BTW, the link here to Awesomium appears to be more current.

Simulate a click on 'a' element using javascript/jquery

The code you've already tried:

document.getElementById("gift-close").click();

...should work as long as the element actually exists in the DOM at the time you run it. Some possible ways to ensure that include:

  1. Run your code from an onload handler for the window. http://jsfiddle.net/LKNYg/
  2. Run your code from a document ready handler if you're using jQuery. http://jsfiddle.net/LKNYg/1/
  3. Put the code in a script block that is after the element in the source html.

So:

$(document).ready(function() {
    document.getElementById("gift-close").click();
    // OR
    $("#gift-close")[0].click();
});

How to get row count in sqlite using Android?

In order to query a table for the number of rows in that table, you want your query to be as efficient as possible. Reference.

Use something like this:

/**
 * Query the Number of Entries in a Sqlite Table
 * */
public long QueryNumEntries()
{
    SQLiteDatabase db = this.getReadableDatabase();
    return DatabaseUtils.queryNumEntries(db, "table_name");
}

java.lang.ClassNotFoundException: javax.servlet.jsp.jstl.core.Config

Add JSTL library as dependency to your project (javax.servlet.jsp.jstl.core.Config is a part of this package). For example, if you were using Gradle, you could write in a build.gradle:

dependencies {
    compile 'javax.servlet:jstl:1.2'
}

Limitations of SQL Server Express

If you switch from Web to Express you will no longer be able to use the SQL Server Agent service so you need to set up a different scheduler for maintenance and backups.

Loop through a comma-separated shell variable

Try this one.

#/bin/bash   
testpid="abc,def,ghij" 
count=`echo $testpid | grep -o ',' | wc -l` # this is not a good way
count=`expr $count + 1` 
while [ $count -gt 0 ]  ; do
     echo $testpid | cut -d ',' -f $i
     count=`expr $count - 1 `
done

CSS rounded corners in IE8

I didnt know about css3pie.com, a very useful site after seeing this post:

But what after testing it out it didnt work for me either. However I found that wrapping it in the .PHP file worked fine. So instead of:

behavior: url(PIE.htc);

use this:

behavior: url(PIE.php);

I put mine in a folder called jquery, so mine was:

 behavior: url(jquery/PIE.php);

So goto their downloads or get it here:

http://css3pie.com/download-latest

And use their PHP file. Inside the PHP file it explains that some servers are not configured for proper .HTC usage. And that was the problem I had.

Try it! I did, it works. Hope this helps others out too.

jQuery.each - Getting li elements inside an ul

First I think you need to fix your lists, as the first node of a <ul> must be a <li> (stackoverflow ref). Once that is setup you can do this:

// note this array has outer scope
var phrases = [];

$('.phrase').each(function(){
        // this is inner scope, in reference to the .phrase element
        var phrase = '';
        $(this).find('li').each(function(){
            // cache jquery var
            var current = $(this);
            // check if our current li has children (sub elements)
            // if it does, skip it
            // ps, you can work with this by seeing if the first child
            // is a UL with blank inside and odd your custom BLANK text
            if(current.children().size() > 0) {return true;}
            // add current text to our current phrase
            phrase += current.text();
        });
        // now that our current phrase is completely build we add it to our outer array
        phrases.push(phrase);
    });
    // note the comma in the alert shows separate phrases
    alert(phrases);

Working jsfiddle.

One thing is if you get the .text() of an upper level li you will get all sub level text with it.

Keeping an array will allow for many multiple phrases to be extracted.


EDIT:

This should work better with an empty UL with no LI:

// outer scope
var phrases = [];

$('.phrase').each(function(){
    // inner scope
    var phrase = '';
    $(this).find('li').each(function(){
        // cache jquery object
        var current = $(this);
        // check for sub levels
        if(current.children().size() > 0) {
            // check is sublevel is just empty UL
            var emptyULtest = current.children().eq(0); 
            if(emptyULtest.is('ul') && $.trim(emptyULtest.text())==""){
                phrase += ' -BLANK- '; //custom blank text
                return true;   
            } else {
             // else it is an actual sublevel with li's
             return true;   
            }
        }
        // if it gets to here it is actual li
        phrase += current.text();
    });
    phrases.push(phrase);
});
// note the comma to separate multiple phrases
alert(phrases);

Randomize numbers with jQuery?

Javascript has a random() available. Take a look at Math.random().

Shell - How to find directory of some command?

An alternative to type -a is command -V

Since most of the times I am interested in the first result only, I also pipe from head. This way the screen will not flood with code in case of a bash function.

command -V lshw | head -n1

How to conditionally take action if FINDSTR fails to find a string

I tried to get this working using FINDSTR, but for some reason my "debugging" command always output an error level of 0:

ECHO %ERRORLEVEL%

My workaround is to use Grep from Cygwin, which outputs the right errorlevel (it will give an errorlevel greater than 0) if a string is not found:

dir c:\*.tib >out 2>>&1
grep "1 File(s)" out
IF %ERRORLEVEL% NEQ 0 "Run other commands" ELSE "Run Errorlevel 0 commands"

Cygwin's grep will also output errorlevel 2 if the file is not found. Here's the hash from my version:

C:\temp\temp>grep --version grep (GNU grep) 2.4.2

C:\cygwin64\bin>md5sum grep.exe c0a50e9c731955628ab66235d10cea23 *grep.exe

C:\cygwin64\bin>sha1sum grep.exe ff43a335bbec71cfe99ce8d5cb4e7c1ecdb3db5c *grep.exe

'cannot open git-upload-pack' error in Eclipse when cloning or pushing git repository

I had a similar problem and a quick fix to your issue is to make sure that you set your JVM option in the eclipse.ini file to use jre7. Older Jre's come with an old local policy file and this will return errors. One quick note also is that you need to point to your javaw not java.

-vm c:\PROGRA~2\Java\jre745\bin\javaw.exe -vmargs -Xms40m -Xmx512m -XX:MaxPermSize=256m -Dsun.lang.ClassLoader.allowArraySyntax=true

How to auto import the necessary classes in Android Studio with shortcut?

On my Mac Auto import option was not showing it was initially hidden

Android studio ->Preferences->editor->General->Auto Import

and then typed in searched field auto then auto import option appeared. And now auto import option is now always shown as default in Editor->General. hopefully this option will also help others. See attached screenshot screenshot

Simulating a click in jQuery/JavaScript on a link

Try this

function submitRequest(buttonId) {
    if (document.getElementById(buttonId) == null
            || document.getElementById(buttonId) == undefined) {
        return;
    }
    if (document.getElementById(buttonId).dispatchEvent) {
        var e = document.createEvent("MouseEvents");
        e.initEvent("click", true, true);
        document.getElementById(buttonId).dispatchEvent(e);
    } else {
        document.getElementById(buttonId).click();
    }
}

and you can use it like

submitRequest("target-element-id");

Key hash for Android-Facebook app

The simplest solution:

  1. Don't add the hash key, implement everything else
  2. When facebook login is pressed, you will get an error saying "Invalid key hash. The key hash "xxx" does not match any stored key. ..."
  3. Open the facebook app dashboard and add the hash "xxx=" ("xxx" hash from the error + "=" sign)

Parsing huge logfiles in Node.js - read in line-by-line

import * as csv from 'fast-csv';
import * as fs from 'fs';
interface Row {
  [s: string]: string;
}
type RowCallBack = (data: Row, index: number) => object;
export class CSVReader {
  protected file: string;
  protected csvOptions = {
    delimiter: ',',
    headers: true,
    ignoreEmpty: true,
    trim: true
  };
  constructor(file: string, csvOptions = {}) {
    if (!fs.existsSync(file)) {
      throw new Error(`File ${file} not found.`);
    }
    this.file = file;
    this.csvOptions = Object.assign({}, this.csvOptions, csvOptions);
  }
  public read(callback: RowCallBack): Promise < Array < object >> {
    return new Promise < Array < object >> (resolve => {
      const readStream = fs.createReadStream(this.file);
      const results: Array < any > = [];
      let index = 0;
      const csvStream = csv.parse(this.csvOptions).on('data', async (data: Row) => {
        index++;
        results.push(await callback(data, index));
      }).on('error', (err: Error) => {
        console.error(err.message);
        throw err;
      }).on('end', () => {
        resolve(results);
      });
      readStream.pipe(csvStream);
    });
  }
}
import { CSVReader } from '../src/helpers/CSVReader';
(async () => {
  const reader = new CSVReader('./database/migrations/csv/users.csv');
  const users = await reader.read(async data => {
    return {
      username: data.username,
      name: data.name,
      email: data.email,
      cellPhone: data.cell_phone,
      homePhone: data.home_phone,
      roleId: data.role_id,
      description: data.description,
      state: data.state,
    };
  });
  console.log(users);
})();

Build Android Studio app via command line

Android Studio automatically creates a Gradle wrapper in the root of your project, which is how it invokes Gradle. The wrapper is basically a script that calls through to the actual Gradle binary and allows you to keep Gradle up to date, which makes using version control easier. To run a Gradle command, you can simply use the gradlew script found in the root of your project (or gradlew.bat on Windows) followed by the name of the task you want to run. For instance, to build a debug version of your Android application, you can run ./gradlew assembleDebug from the root of your repository. In a default project setup, the resulting apk can then be found in app/build/outputs/apk/app-debug.apk. On a *nix machine, you can also just run find . -name '*.apk' to find it, if it's not there.

How to overlay image with color in CSS?

If you want to just add a class to add the overlay:

_x000D_
_x000D_
span {_x000D_
  padding: 5px;_x000D_
}_x000D_
_x000D_
.green {_x000D_
  background-color: green;_x000D_
  color: #FFF;_x000D_
}_x000D_
_x000D_
.overlayed {_x000D_
  position: relative;_x000D_
}_x000D_
_x000D_
.overlayed::before {_x000D_
  content: ' ';_x000D_
  z-index: 1;_x000D_
  position: absolute;_x000D_
  top: 0;_x000D_
  bottom: 0;_x000D_
  left: 0;_x000D_
  right: 0;_x000D_
  background-color: #00000080;_x000D_
}_x000D_
_x000D_
.stand-out {_x000D_
  position: relative;_x000D_
  z-index: 2;_x000D_
}
_x000D_
<span class="green overlayed">with overlay</span>_x000D_
<span class="green">without overlay</span>_x000D_
<br>_x000D_
<br>_x000D_
<span class="green overlayed">_x000D_
  <span class="stand-out">I stand out</span>_x000D_
</span>
_x000D_
_x000D_
_x000D_

Important: the element you put the overlayed class on needs to have a position set. If it doesn't, the ::before element will take the size of some other parent element. In my example I've set the position to "relative" via the .overlayed rule, but in your use case you might need "absolute" or some other value.

Also, make sure that the z-index of the overlayed class is higher than the ones of the eventual child elements of the container, unless you actually want for those to "stand out" and not be overlayed (as with the span with the stand-out class, in my snippet).

Difference between Select Unique and Select Distinct

Unique is a keyword used in the Create Table() directive to denote that a field will contain unique data, usually used for natural keys, foreign keys etc.

For example:

Create Table Employee(   
    Emp_PKey Int Identity(1, 1) Constraint PK_Employee_Emp_PKey Primary Key,  
    Emp_SSN Numeric Not Null Unique,  
    Emp_FName varchar(16),   
    Emp_LName varchar(16) 
)

i.e. Someone's Social Security Number would likely be a unique field in your table, but not necessarily the primary key.

Distinct is used in the Select statement to notify the query that you only want the unique items returned when a field holds data that may not be unique.

Select Distinct Emp_LName
From Employee

You may have many employees with the same last name, but you only want each different last name.

Obviously if the field you are querying holds unique data, then the Distinct keyword becomes superfluous.

How to draw an empty plot?

There is an interest in your solution that plot.new() hasn't though: in the empty plot you "draw" you can write text at specified coordinates with text(x = ..., y = ..., your_text).

Confused by python file mode "w+"

r for read

w for write

r+ for read/write without deleting the original content if file exists, otherwise raise exception

w+ for delete the original content then read/write if file exists, otherwise create the file

For example,

>>> with open("file1.txt", "w") as f:
...   f.write("ab\n")
... 
>>> with open("file1.txt", "w+") as f:
...   f.write("c")
... 

$ cat file1.txt 
c$
>>> with open("file2.txt", "r+") as f:
...   f.write("ab\n")
... 
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
IOError: [Errno 2] No such file or directory: 'file2.txt'

>>> with open("file2.txt", "w") as f:
...   f.write("ab\n")
... 
>>> with open("file2.txt", "r+") as f:
...   f.write("c")
... 

$ cat file2.txt 
cb
$

Converting Object to JSON and JSON to Object in PHP, (library like Gson for Java)

I made a method to solve this. My approach is:

1 - Create a abstract class that have a method to convert Objects to Array (including private attr) using Regex. 2 - Convert the returned array to json.

I use this Abstract class as parent of all my domain classes

Class code:

namespace Project\core;

abstract class AbstractEntity {
    public function getAvoidedFields() {
        return array ();
    }
    public function toArray() {
        $temp = ( array ) $this;

        $array = array ();

        foreach ( $temp as $k => $v ) {
            $k = preg_match ( '/^\x00(?:.*?)\x00(.+)/', $k, $matches ) ? $matches [1] : $k;
            if (in_array ( $k, $this->getAvoidedFields () )) {
                $array [$k] = "";
            } else {

                // if it is an object recursive call
                if (is_object ( $v ) && $v instanceof AbstractEntity) {
                    $array [$k] = $v->toArray();
                }
                // if its an array pass por each item
                if (is_array ( $v )) {

                    foreach ( $v as $key => $value ) {
                        if (is_object ( $value ) && $value instanceof AbstractEntity) {
                            $arrayReturn [$key] = $value->toArray();
                        } else {
                            $arrayReturn [$key] = $value;
                        }
                    }
                    $array [$k] = $arrayReturn;
                }
                // if it is not a array and a object return it
                if (! is_object ( $v ) && !is_array ( $v )) {
                    $array [$k] = $v;
                }
            }
        }

        return $array;
    }
}

Java List.contains(Object with field value equal to x)

Eclipse Collections

If you're using Eclipse Collections, you can use the anySatisfy() method. Either adapt your List in a ListAdapter or change your List into a ListIterable if possible.

ListIterable<MyObject> list = ...;

boolean result =
    list.anySatisfy(myObject -> myObject.getName().equals("John"));

If you'll do operations like this frequently, it's better to extract a method which answers whether the type has the attribute.

public class MyObject
{
    private final String name;

    public MyObject(String name)
    {
        this.name = name;
    }

    public boolean named(String name)
    {
        return Objects.equals(this.name, name);
    }
}

You can use the alternate form anySatisfyWith() together with a method reference.

boolean result = list.anySatisfyWith(MyObject::named, "John");

If you cannot change your List into a ListIterable, here's how you'd use ListAdapter.

boolean result = 
    ListAdapter.adapt(list).anySatisfyWith(MyObject::named, "John");

Note: I am a committer for Eclipse ollections.

Bind failed: Address already in use

It also happens when you have not give enough permissions(read and write) to your sock file!

Just add expected permission to your sock contained folder and your sock file:

 chmod ug+rw /path/to/your/
 chmod ug+rw /path/to/your/file.sock

Then have fun!

Simple logical operators in Bash

very close

if [[ $varA -eq 1 ]] && [[ $varB == 't1' || $varC == 't2' ]]; 
  then 
    scale=0.05
  fi

should work.

breaking it down

[[ $varA -eq 1 ]] 

is an integer comparison where as

$varB == 't1'

is a string comparison. otherwise, I am just grouping the comparisons correctly.

Double square brackets delimit a Conditional Expression. And, I find the following to be a good reading on the subject: "(IBM) Demystify test, [, [[, ((, and if-then-else"

How to get an input text value in JavaScript

Notice that this line:

lol = document.getElementById('lolz').value;

is before the actual <input> element on your markup:

<input type="text" name="enter" class="enter" value="" id="lolz"/>

Your code is parsed line by line, and the lol = ... line is evaluated before the browser knows about the existance of an input with id lolz. Thus, document.getElementById('lolz') will return null, and document.getElementById('lolz').value should cause an error.

Move that line inside the function, and it should work. This way, that line will only run when the function is called. And use var as others suggested, to avoid making it a global variable:

function kk(){
    var lol = document.getElementById('lolz').value;
    alert(lol);
}

You can also move the script to the end of the page. Moving all script blocks to the end of your HTML <body> is the standard practice today to avoid this kind of reference problem. It also tends to speed up page load, since scripts that take long to load and parse are processed after the HTML has been (mostly) displayed.

Iterate Multi-Dimensional Array with Nested Foreach Statement

The 2D array in C# does not lend itself well to a nested foreach, it is not the equivalent of a jagged array (an array of arrays). You could do something like this to use a foreach

foreach (int i in Enumerable.Range(0, array.GetLength(0)))
    foreach (int j in Enumerable.Range(0, array.GetLength(1)))
        Console.WriteLine(array[i, j]);

But you would still use i and j as index values for the array. Readability would be better preserved if you just went for the garden variety for loop instead.

Spool Command: Do not output SQL statement to file

You can directly export the query result with export option in the result grig. This export has various options to export. I think this will work.

Count unique values using pandas groupby

I know it has been a while since this was posted, but I think this will help too. I wanted to count unique values and filter the groups by number of these unique values, this is how I did it:

df.groupby('group').agg(['min','max','count','nunique']).reset_index(drop=False)

Python: How to convert datetime format?

>>> import datetime
>>> d = datetime.datetime.strptime('2011-06-09', '%Y-%m-%d')
>>> d.strftime('%b %d,%Y')
'Jun 09,2011'

In pre-2.5 Python, you can replace datetime.strptime with time.strptime, like so (untested): datetime.datetime(*(time.strptime('2011-06-09', '%Y-%m-%d')[0:6]))

Laravel 4: how to run a raw SQL?

The best way to do this I have found so far it to side step Laravel and execute the query directly using the Pdo object.

Example

DB::connection()->getPdo()->exec( $sql );

I usually find it faster and more efficient for a one time query to simply open my database query tool and type the query with full syntax checking then execute it directly.

This becomes essential if you have to work with stored procedures or need to use any database functions

Example 2 setting created_at to a the value you need it to be and side steeping any carbon funkiness

$sql = 'UPDATE my_table SET updated_at = FROM_UNIXTIME(nonce) WHERE id = ' . strval($this->id);
DB::statement($sql);

I found this worked in a controller but not in a migration

Converting .NET DateTime to JSON

What is returned is milliseconds since epoch. You could do:

var d = new Date();
d.setTime(1245398693390);
document.write(d);

On how to format the date exactly as you want, see full Date reference at http://www.w3schools.com/jsref/jsref_obj_date.asp

You could strip the non-digits by either parsing the integer (as suggested here):

var date = new Date(parseInt(jsonDate.substr(6)));

Or applying the following regular expression (from Tominator in the comments):

var jsonDate = jqueryCall();  // returns "/Date(1245398693390)/"; 
var re = /-?\d+/; 
var m = re.exec(jsonDate); 
var d = new Date(parseInt(m[0]));

Jquery, checking if a value exists in array or not

    if ($.inArray('yourElement', yourArray) > -1)
    {
        //yourElement in yourArray
        //code here

    }

Reference: Jquery Array

The $.inArray() method is similar to JavaScript's native .indexOf() method in that it returns -1 when it doesn't find a match. If the first element within the array matches value, $.inArray() returns 0.

Transparent scrollbar with css

if you don't have any content with 100% width, you can set the background color of the track to the same color of the body's background

Using pip behind a proxy with CNTLM

I solved the problem with PIP in Windows using "Fiddler" (https://www.telerik.com/download/fiddler). After downloading and installing, do the following:

"Rules" => click "Automatically Authenticate"

Example: pip install virtualenv -proxy 127.0.0.1:8888

Just open your prompt and use.

https://github.com/pypa/pip/issues/1182 Search for "voltagex" (commented on 22 May 2015)

Tried to Load Angular More Than Once

I had that problem on code pen, and it turn out it's just because I was loading JQuery before Angular. Don't know if that can apply for other cases.

Passing an array of data as an input parameter to an Oracle procedure

This is one way to do it:

SQL> set serveroutput on
SQL> CREATE OR REPLACE TYPE MyType AS VARRAY(200) OF VARCHAR2(50);
  2  /

Type created

SQL> CREATE OR REPLACE PROCEDURE testing (t_in MyType) IS
  2  BEGIN
  3    FOR i IN 1..t_in.count LOOP
  4      dbms_output.put_line(t_in(i));
  5    END LOOP;
  6  END;
  7  /

Procedure created

SQL> DECLARE
  2    v_t MyType;
  3  BEGIN
  4    v_t := MyType();
  5    v_t.EXTEND(10);
  6    v_t(1) := 'this is a test';
  7    v_t(2) := 'A second test line';
  8    testing(v_t);
  9  END;
 10  /

this is a test
A second test line

To expand on my comment to @dcp's answer, here's how you could implement the solution proposed there if you wanted to use an associative array:

SQL> CREATE OR REPLACE PACKAGE p IS
  2    TYPE p_type IS TABLE OF VARCHAR2(50) INDEX BY BINARY_INTEGER;
  3  
  4    PROCEDURE pp (inp p_type);
  5  END p;
  6  /

Package created
SQL> CREATE OR REPLACE PACKAGE BODY p IS
  2    PROCEDURE pp (inp p_type) IS
  3    BEGIN
  4      FOR i IN 1..inp.count LOOP
  5        dbms_output.put_line(inp(i));
  6      END LOOP;
  7    END pp;
  8  END p;
  9  /

Package body created
SQL> DECLARE
  2    v_t p.p_type;
  3  BEGIN
  4    v_t(1) := 'this is a test of p';
  5    v_t(2) := 'A second test line for p';
  6    p.pp(v_t);
  7  END;
  8  /

this is a test of p
A second test line for p

PL/SQL procedure successfully completed

SQL> 

This trades creating a standalone Oracle TYPE (which cannot be an associative array) with requiring the definition of a package that can be seen by all in order that the TYPE it defines there can be used by all.

How do I use a C# Class Library in a project?

You need to add a reference to your class library from your project. Right click on the references folder and click add reference. You can either browse for the DLL or, if your class libaray is a project in your solution you can add a project reference.

Get next element in foreach loop

The general solution could be a caching iterator. A properly implemented caching iterator works with any Iterator, and saves memory. PHP SPL has a CachingIterator, but it is very odd, and has very limited functionality. However, you can write your own lookahead iterator like this:

<?php

class NeighborIterator implements Iterator
{

    protected $oInnerIterator;

    protected $hasPrevious = false;
    protected $previous = null;
    protected $previousKey = null;

    protected $hasCurrent = false;
    protected $current = null;
    protected $currentKey = null;

    protected $hasNext = false;
    protected $next = null;
    protected $nextKey = null;

    public function __construct(Iterator $oInnerIterator)
    {
        $this->oInnerIterator = $oInnerIterator;
    }

    public function current()
    {
        return $this->current;
    }

    public function key()
    {
        return $this->currentKey;
    }

    public function next()
    {
        if ($this->hasCurrent) {
            $this->hasPrevious = true;
            $this->previous = $this->current;
            $this->previousKey = $this->currentKey;
            $this->hasCurrent = $this->hasNext;
            $this->current = $this->next;
            $this->currentKey = $this->nextKey;
            if ($this->hasNext) {
                $this->oInnerIterator->next();
                $this->hasNext = $this->oInnerIterator->valid();
                if ($this->hasNext) {
                    $this->next = $this->oInnerIterator->current();
                    $this->nextKey = $this->oInnerIterator->key();
                } else {
                    $this->next = null;
                    $this->nextKey = null;
                }
            }
        }
    }

    public function rewind()
    {
        $this->hasPrevious = false;
        $this->previous = null;
        $this->previousKey = null;
        $this->oInnerIterator->rewind();
        $this->hasCurrent = $this->oInnerIterator->valid();
        if ($this->hasCurrent) {
            $this->current = $this->oInnerIterator->current();
            $this->currentKey = $this->oInnerIterator->key();
            $this->oInnerIterator->next();
            $this->hasNext = $this->oInnerIterator->valid();
            if ($this->hasNext) {
                $this->next = $this->oInnerIterator->current();
                $this->nextKey = $this->oInnerIterator->key();
            } else {
                $this->next = null;
                $this->nextKey = null;
            }
        } else {
            $this->current = null;
            $this->currentKey = null;
            $this->hasNext = false;
            $this->next = null;
            $this->nextKey = null;
        }
    }

    public function valid()
    {
        return $this->hasCurrent;
    }

    public function hasNext()
    {
        return $this->hasNext;
    }

    public function getNext()
    {
        return $this->next;
    }

    public function getNextKey()
    {
        return $this->nextKey;
    }

    public function hasPrevious()
    {
        return $this->hasPrevious;
    }

    public function getPrevious()
    {
        return $this->previous;
    }

    public function getPreviousKey()
    {
        return $this->previousKey;
    }

}


header("Content-type: text/plain; charset=utf-8");
$arr = [
    "a" => "alma",
    "b" => "banan",
    "c" => "cseresznye",
    "d" => "dio",
    "e" => "eper",
];
$oNeighborIterator = new NeighborIterator(new ArrayIterator($arr));
foreach ($oNeighborIterator as $key => $value) {

    // you can get previous and next values:

    if (!$oNeighborIterator->hasPrevious()) {
        echo "{FIRST}\n";
    }
    echo $oNeighborIterator->getPreviousKey() . " => " . $oNeighborIterator->getPrevious() . " ----->        ";
    echo "[ " . $key . " => " . $value . " ]        -----> ";
    echo $oNeighborIterator->getNextKey() . " => " . $oNeighborIterator->getNext() . "\n";
    if (!$oNeighborIterator->hasNext()) {
        echo "{LAST}\n";
    }
}

Command line: search and replace in all filenames matched by grep

find . -type f -print0 | xargs -0 <sed/perl/ruby cmd> will process multiple space contained file names at once loading one interpreter per batch. Much faster.

Drawing circles with System.Drawing

There is no DrawCircle method; use DrawEllipse instead. I have a static class with handy graphics extension methods. The following ones draw and fill circles. They are wrappers around DrawEllipse and FillEllipse:

public static class GraphicsExtensions
{
    public static void DrawCircle(this Graphics g, Pen pen,
                                  float centerX, float centerY, float radius)
    {
        g.DrawEllipse(pen, centerX - radius, centerY - radius,
                      radius + radius, radius + radius);
    }

    public static void FillCircle(this Graphics g, Brush brush,
                                  float centerX, float centerY, float radius)
    {
        g.FillEllipse(brush, centerX - radius, centerY - radius,
                      radius + radius, radius + radius);
    }
}

You can call them like this:

g.FillCircle(myBrush, centerX, centerY, radius);
g.DrawCircle(myPen, centerX, centerY, radius);

How to draw lines in Java

A very simple example of a swing component to draw lines. It keeps internally a list with the lines that have been added with the method addLine. Each time a new line is added, repaint is invoked to inform the graphical subsytem that a new paint is required.

The class also includes some example of usage.

import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.util.LinkedList;

import javax.swing.JButton;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JPanel;

public class LinesComponent extends JComponent{

private static class Line{
    final int x1; 
    final int y1;
    final int x2;
    final int y2;   
    final Color color;

    public Line(int x1, int y1, int x2, int y2, Color color) {
        this.x1 = x1;
        this.y1 = y1;
        this.x2 = x2;
        this.y2 = y2;
        this.color = color;
    }               
}

private final LinkedList<Line> lines = new LinkedList<Line>();

public void addLine(int x1, int x2, int x3, int x4) {
    addLine(x1, x2, x3, x4, Color.black);
}

public void addLine(int x1, int x2, int x3, int x4, Color color) {
    lines.add(new Line(x1,x2,x3,x4, color));        
    repaint();
}

public void clearLines() {
    lines.clear();
    repaint();
}

@Override
protected void paintComponent(Graphics g) {
    super.paintComponent(g);
    for (Line line : lines) {
        g.setColor(line.color);
        g.drawLine(line.x1, line.y1, line.x2, line.y2);
    }
}

public static void main(String[] args) {
    JFrame testFrame = new JFrame();
    testFrame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
    final LinesComponent comp = new LinesComponent();
    comp.setPreferredSize(new Dimension(320, 200));
    testFrame.getContentPane().add(comp, BorderLayout.CENTER);
    JPanel buttonsPanel = new JPanel();
    JButton newLineButton = new JButton("New Line");
    JButton clearButton = new JButton("Clear");
    buttonsPanel.add(newLineButton);
    buttonsPanel.add(clearButton);
    testFrame.getContentPane().add(buttonsPanel, BorderLayout.SOUTH);
    newLineButton.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            int x1 = (int) (Math.random()*320);
            int x2 = (int) (Math.random()*320);
            int y1 = (int) (Math.random()*200);
            int y2 = (int) (Math.random()*200);
            Color randomColor = new Color((float)Math.random(), (float)Math.random(), (float)Math.random());
            comp.addLine(x1, y1, x2, y2, randomColor);
        }
    });
    clearButton.addActionListener(new ActionListener() {

        @Override
        public void actionPerformed(ActionEvent e) {
            comp.clearLines();
        }
    });
    testFrame.pack();
    testFrame.setVisible(true);
}

}

How do I get a file's directory using the File object?

File directory = new File("Enter any 
                directory name or file name");
boolean isDirectory = directory.isDirectory();
if (isDirectory) {
  // It returns true if directory is a directory.
  System.out.println("the name you have entered 
         is a directory  : "  +    directory);  
  //It returns the absolutepath of a directory.
  System.out.println("the path is "  + 
              directory.getAbsolutePath());
} else {
  // It returns false if directory is a file.
  System.out.println("the name you have
   entered is a file  : " +   directory);
  //It returns the absolute path of a file.
  System.out.println("the path is "  +  
            file.getParent());
}

Is it possible to make Font Awesome icons larger than 'fa-5x'?

Font awesome use SVG icons. So, you can resize it for your requirment.

just use CSS class for that,

    .large-icon{
       font-size:10em;
       //or
      font-size:200%;
      //or
      font-size:50px;
    }