Programs & Examples On #Ora 12541

ORA-12541: TNS no listener

Oracle client ORA-12541: TNS:no listener

According to oracle online documentation

ORA-12541: TNS:no listener

Cause: The connection request could not be completed because the listener is not running.

Action: Ensure that the supplied destination address matches one of the addresses used by 
the listener - compare the TNSNAMES.ORA entry with the appropriate LISTENER.ORA file (or  
TNSNAV.ORA if the connection is to go by way of an Interchange). Start the listener on 
the remote machine.

How can I convert radians to degrees with Python?

You can simply convert your radian result to degree by using

math.degrees and rounding appropriately to the required decimal places

for example

>>> round(math.degrees(math.asin(0.5)),2)
30.0
>>> 

How do you connect to multiple MySQL databases on a single webpage?

Warning : mysql_xx functions are deprecated since php 5.5 and removed since php 7.0 (see http://php.net/manual/intro.mysql.php), use mysqli_xx functions or see the answer below from @Troelskn


You can make multiple calls to mysql_connect(), but if the parameters are the same you need to pass true for the '$new_link' (fourth) parameter, otherwise the same connection is reused. For example:

$dbh1 = mysql_connect($hostname, $username, $password); 
$dbh2 = mysql_connect($hostname, $username, $password, true); 

mysql_select_db('database1', $dbh1);
mysql_select_db('database2', $dbh2);

Then to query database 1 pass the first link identifier:

mysql_query('select * from tablename', $dbh1);

and for database 2 pass the second:

mysql_query('select * from tablename', $dbh2);

If you do not pass a link identifier then the last connection created is used (in this case the one represented by $dbh2) e.g.:

mysql_query('select * from tablename');

Other options

If the MySQL user has access to both databases and they are on the same host (i.e. both DBs are accessible from the same connection) you could:

  • Keep one connection open and call mysql_select_db() to swap between as necessary. I am not sure this is a clean solution and you could end up querying the wrong database.
  • Specify the database name when you reference tables within your queries (e.g. SELECT * FROM database2.tablename). This is likely to be a pain to implement.

Also please read troelskn's answer because that is a better approach if you are able to use PDO rather than the older extensions.

Execute SQL script from command line

You can do like this

sqlcmd -S <server Name> -U sa -P sapassword -i inputquery_file_name -o outputfile_name

From your command prompt run sqlcmd /? to get all the options you can use with sqlcmd utility

Equivalent of Math.Min & Math.Max for Dates?

There's no built in method to do that. You can use the expression:

(date1 > date2 ? date1 : date2)

to find the maximum of the two.

You can write a generic method to calculate Min or Max for any type (provided that Comparer<T>.Default is set appropriately):

public static T Max<T>(T first, T second) {
    if (Comparer<T>.Default.Compare(first, second) > 0)
        return first;
    return second;
}

You can use LINQ too:

new[]{date1, date2, date3}.Max()

Counting number of characters in a file through shell script

#!/bin/sh

wc -m $1 | awk '{print $1}'

wc -m counts the number of characters; the awk command prints the number of characters only, omitting the filename.

wc -c would give you the number of bytes (which can be different to the number of characters, as depending on the encoding you may have a character encoded on several bytes).

Determine if JavaScript value is an "integer"?

Here's a polyfill for the Number predicate functions:

"use strict";

Number.isNaN = Number.isNaN ||
    n => n !== n; // only NaN

Number.isNumeric = Number.isNumeric ||
    n => n === +n; // all numbers excluding NaN

Number.isFinite = Number.isFinite ||
    n => n === +n               // all numbers excluding NaN
      && n >= Number.MIN_VALUE  // and -Infinity
      && n <= Number.MAX_VALUE; // and +Infinity

Number.isInteger = Number.isInteger ||
    n => n === +n              // all numbers excluding NaN
      && n >= Number.MIN_VALUE // and -Infinity
      && n <= Number.MAX_VALUE // and +Infinity
      && !(n % 1);             // and non-whole numbers

Number.isSafeInteger = Number.isSafeInteger ||
    n => n === +n                     // all numbers excluding NaN
      && n >= Number.MIN_SAFE_INTEGER // and small unsafe numbers
      && n <= Number.MAX_SAFE_INTEGER // and big unsafe numbers
      && !(n % 1);                    // and non-whole numbers

All major browsers support these functions, except isNumeric, which is not in the specification because I made it up. Hence, you can reduce the size of this polyfill:

"use strict";

Number.isNumeric = Number.isNumeric ||
    n => n === +n; // all numbers excluding NaN

Alternatively, just inline the expression n === +n manually.

Error - is not marked as serializable

You need to add a Serializable attribute to the class which you want to serialize.

[Serializable]
public class OrgPermission

Getting parts of a URL (Regex)

I like the regex that was published in "Javascript: The Good Parts". Its not too short and not too complex. This page on github also has the JavaScript code that uses it. But it an be adapted for any language. https://gist.github.com/voodooGQ/4057330

What is Node.js' Connect, Express and "middleware"?

Node.js itself offers an HTTP module, whose createServer method returns an object that you can use to respond to HTTP requests. That object inherits the http.Server prototype.

how to install python distutils

The simplest way to install setuptools when it isn't already there and you can't use a package manager is to download ez_setup.py and run it with the appropriate Python interpreter. This works even if you have multiple versions of Python around: just run ez_setup.py once with each Python.

Edit: note that recent versions of Python 3 include setuptools in the distribution so you no longer need to install separately. The script mentioned here is only relevant for old versions of Python.

node.js, socket.io with SSL

This is my nginx config file and iosocket code. Server(express) is listening on port 9191. It works well: nginx config file:

server {
    listen       443 ssl;
    server_name  localhost;
    root   /usr/share/nginx/html/rdist;

    location /user/ {
        proxy_pass   http://localhost:9191;
    }
    location /api/ {
        proxy_pass   http://localhost:9191;
    }
    location /auth/ {
        proxy_pass   http://localhost:9191;
    }

    location / {
        index  index.html index.htm;
        if (!-e $request_filename){
          rewrite ^(.*)$ /index.html break;
        }
    }
    location /socket.io/ {
        proxy_set_header Upgrade $http_upgrade;
        proxy_set_header Connection "upgrade";
        proxy_pass   http://localhost:9191/socket.io/;
    }


    error_page   500 502 503 504  /50x.html;
    location = /50x.html {
        root   /usr/share/nginx/html;
    }

    ssl_certificate /etc/nginx/conf.d/sslcert/xxx.pem;
    ssl_certificate_key /etc/nginx/conf.d/sslcert/xxx.key;

}

Server:

const server = require('http').Server(app)
const io = require('socket.io')(server)
io.on('connection', (socket) => {
    handleUserConnect(socket)

  socket.on("disconnect", () => {
   handleUserDisConnect(socket)
  });
})

server.listen(9191, function () {
  console.log('Server listening on port 9191')
})

Client(react):

    const socket = io.connect('', { secure: true, query: `userId=${this.props.user._id}` })

        socket.on('notifications', data => {
            console.log('Get messages from back end:', data)
            this.props.mergeNotifications(data)
        })

How to populate options of h:selectOneMenu from database?

Call me lazy but coding a Converter seems like a lot of unnecessary work. I'm using Primefaces and, not having used a plain vanilla JSF2 listbox or dropdown menu before, I just assumed (being lazy) that the widget could handle complex objects, i.e. pass the selected object as is to its corresponding getter/setter like so many other widgets do. I was disappointed to find (after hours of head scratching) that this capability does not exist for this widget type without a Converter. In fact if you supply a setter for the complex object rather than for a String, it fails silently (simply doesn't call the setter, no Exception, no JS error), and I spent a ton of time going through BalusC's excellent troubleshooting tool to find the cause, to no avail since none of those suggestions applied. My conclusion: listbox/menu widget needs adapting that other JSF2 widgets do not. This seems misleading and prone to leading the uninformed developer like myself down a rabbit hole.

In the end I resisted coding a Converter and found through trial and error that if you set the widget value to a complex object, e.g.:

<p:selectOneListbox id="adminEvents" value="#{testBean.selectedEvent}">

... when the user selects an item, the widget can call a String setter for that object, e.g. setSelectedThing(String thingString) {...}, and the String passed is a JSON String representing the Thing object. I can parse it to determine which object was selected. This feels a little like a hack, but less of a hack than a Converter.

Setting up Gradle for api 26 (Android)

you must add in your MODULE-LEVEL build.gradle file with:

//module-level build.gradle file
repositories {
    maven {
        url 'https://maven.google.com'

    }
}

see: Google's Maven repository

I have observed that when I use Android Studio 2.3.3 I MUST add repositories{maven{url 'https://maven.google.com'}} in MODULE-LEVEL build.gradle. In the case of Android Studio 3.0.0 there is no need for the addition in module-level build.gradle. It is enough the addition in project-level build.gradle which has been referred to in the other posts here, namely:

//project-level build.gradle file
allprojects {
 repositories {
    jcenter()
    maven {
        url 'https://maven.google.com/'
        name 'Google'
    }
  }
}

UPDATE 11-14-2017: The solution, that I present, was valid when I did the post. Since then, there have been various updates (even with respect to the site I refer to), and I do not know if now is valid. For one month I did my work depending on the solution above, until I upgraded to Android Studio 3.0.0

How to search through all Git and Mercurial commits in the repository for a certain string?

In Mercurial you use hg log --keyword to search for keywords in the commit messages and hg log --user to search for a particular user. See hg help log for other ways to limit the log.

Convert Unicode to ASCII without errors in Python

For broken consoles like cmd.exe and HTML output you can always use:

my_unicode_string.encode('ascii','xmlcharrefreplace')

This will preserve all the non-ascii chars while making them printable in pure ASCII and in HTML.

WARNING: If you use this in production code to avoid errors then most likely there is something wrong in your code. The only valid use case for this is printing to a non-unicode console or easy conversion to HTML entities in an HTML context.

And finally, if you are on windows and use cmd.exe then you can type chcp 65001 to enable utf-8 output (works with Lucida Console font). You might need to add myUnicodeString.encode('utf8').

bash script read all the files in directory

You can go without the loop:

find /path/to/dir -type f -exec /your/first/command \{\} \; -exec /your/second/command \{\} \; 

HTH

Specifying onClick event type with Typescript and React.Konva

You should be using event.currentTarget. React is mirroring the difference between currentTarget (element the event is attached to) and target (the element the event is currently happening on). Since this is a mouse event, type-wise the two could be different, even if it doesn't make sense for a click.

https://github.com/facebook/react/issues/5733 https://developer.mozilla.org/en-US/docs/Web/API/Event/currentTarget

Using sed, how do you print the first 'N' characters of a line?

Strictly with sed:

grep ... | sed -e 's/^\(.\{N\}\).*$/\1/'

Set cURL to use local virtual hosts

Either use a real fully qualified domain name (like dev.yourdomain.com) that pointing to 127.0.0.1 or try editing the proper hosts file (usually /etc/hosts in *nix environments).

How to implement OnFragmentInteractionListener

Just an addendum:

OnFragmentInteractionListener handle communication between Activity and Fragment using an interface (OnFragmentInteractionListener) and is created by default by Android Studio, but if you dont need to communicate with your activity, you can just get ride of it.

The goal is that you can attach your fragment to multiple activities and still reuse the same communication approach (Every activity could have its own OnFragmentInteractionListener for each fragment).

But and if im sure my fragment will be attached to only one type of activity and i want to communicate with that activity?

Then, if you dont want to use OnFragmentInteractionListener because of its verbosity, you can access your activity methods using:

((MyActivityClass) getActivity()).someMethod()

Error In PHP5 ..Unable to load dynamic library

sudo apt-get install php5-mcrypt
sudo apt-get install php5-mysql

...etc resolved it for me :)

hope it helps

Div not expanding even with content inside

Add <br style="clear: both" /> after the last floated div worked for me.

Where is database .bak file saved from SQL Server Management Studio?

Set registry item for your server instance. For example:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Microsoft SQL Server\MSSQL.2\MSSQLServer\BackupDirectory

How to convert ‘false’ to 0 and ‘true’ to 1 in Python

You can use x.astype('uint8') where x is your Boolean array.

Uncaught Invariant Violation: Too many re-renders. React limits the number of renders to prevent an infinite loop

I also have the same problem, and the solution is I didn't bind the event in my onClick. so when it renders for the first time and the data is more, which ends up calling the state setter again, which triggers React to call your function again and so on.

export default function Component(props) {

function clickEvent (event, variable){
    console.log(variable);
}

return (
    <div>
        <IconButton
            key="close"
            aria-label="Close"
            color="inherit"
            onClick={e => clickEvent(e, 10)} // or you can call like this:onClick={() => clickEvent(10)} 
        >
    </div>
)
}

Section vs Article HTML5

also, for syndicated content "Authors are encouraged to use the article element instead of the section element when it would make sense to syndicate the contents of the element."

How do I find the data directory for a SQL Server instance?

From the GUI: open your server properties, go to Database Settings, and see Database default locations.

Note that you can drop your database files wherever you like, though it seems cleaner to keep them in the default directory.

Bootstrap 3 - disable navbar collapse

Another way is to simply remove collapse navbar-collapse from the markup. Example with Bootstrap 3.3.7

_x000D_
_x000D_
<link href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css" rel="stylesheet" integrity="sha384-BVYiiSIFeK1dGmJRAkycuHAHRg32OmUcww7on3RYdg4Va+PmSTsz/K68vbdEjh4u" crossorigin="anonymous">_x000D_
_x000D_
<nav class="navbar navbar-atp">_x000D_
  <div class="container-fluid">_x000D_
    <div class="">_x000D_
      <ul class="nav navbar-nav nav-custom">_x000D_
        <li>_x000D_
          <a href="#" id="sidebar-btn"><span class="fa fa-bars">Toggle btn</span></a>_x000D_
        </li>_x000D_
      </ul>_x000D_
      <ul class="nav navbar-nav navbar-right">_x000D_
        <li>Nav item</li>_x000D_
      </ul>_x000D_
    </div>_x000D_
  </div>_x000D_
</nav>
_x000D_
_x000D_
_x000D_

How can change width of dropdown list?

The dropdown width itself cannot be set. It's width depend on the option-values. See also here ( jsfiddle.net/LgS3C/ )

How the select box looks like is also depending on your browser.

You can build your own control or use Select2 https://select2.org

Run a script in Dockerfile

Try to create script with ADD command and specification of working directory Like this("script" is the name of script and /root/script.sh is where you want it in the container, it can be different path:

ADD script.sh /root/script.sh

In this case ADD has to come before CMD, if you have one BTW it's cool way to import scripts to any location in container from host machine

In CMD place [./script]

It should automatically execute your script

You can also specify WORKDIR as /root, then you'l be automatically placed in root, upon starting a container

How do I show running processes in Oracle DB?

Keep in mind that there are processes on the database which may not currently support a session.

If you're interested in all processes you'll want to look to v$process (or gv$process on RAC)

load Js file in HTML

I had the same problem, and found the answer. If you use node.js with express, you need to give it its own function in order for the js file to be reached. For example:

const script = path.join(__dirname, 'script.js');
const server = express().get('/', (req, res) => res.sendFile(script))

What are the differences between virtual memory and physical memory?

I am shamelessly copying the excerpts from man page of top

VIRT -- Virtual Image (kb) The total amount of virtual memory used by the task. It includes all code, data and shared libraries plus pages that have been swapped out and pages that have been mapped but not used.

SWAP -- Swapped size (kb) Memory that is not resident but is present in a task. This is memory that has been swapped out but could include additional non- resident memory. This column is calculated by subtracting physical memory from virtual memory

How To Raise Property Changed events on a Dependency Property?

I question the logic of raising a PropertyChanged event on the second property when it's the first property that's changing. If the second properties value changes then the PropertyChanged event could be raised there.

At any rate, the answer to your question is you should implement INotifyPropertyChange. This interface contains the PropertyChanged event. Implementing INotifyPropertyChanged lets other code know that the class has the PropertyChanged event, so that code can hook up a handler. After implementing INotifyPropertyChange, the code that goes in the if statement of your OnPropertyChanged is:

if (PropertyChanged != null)
    PropertyChanged(new PropertyChangedEventArgs("MySecondProperty"));

Delete data with foreign key in SQL Server table

SET foreign_key_checks = 0; DELETE FROM yourtable; SET foreign_key_checks = 1;

less than 10 add 0 to number

Make a function that you can reuse:

function minTwoDigits(n) {
  return (n < 10 ? '0' : '') + n;
}

Then use it in each part of the coordinates:

c += minTwoDigits(deg) + "° ";

and so on.

How can I make an svg scale with its parent container?

Adjusting the currentScale attribute works in IE ( I tested with IE 11), but not in Chrome.

Vagrant error : Failed to mount folders in Linux guest

I arrived at this page whilst looking for the same error message. For me the cause was different: I had ran a yum update on the system that installed a new kernel. The guest additions where out of date so it couldn't load them.

I rebuilt them with

sudo /etc/init.d/vboxadd setup 

And a vagrant reload later my guest was up and running again.

I'm just adding it here in case someone else gets here the same way I did.

Edit (Per KCD's comment):
It is possible that you get an error saying:

The headers for the current running kernel were not found

This can be resolved by installing kernel-devel (yum install kernel-devel)

Iterating through struct fieldnames in MATLAB

Your fns is a cellstr array. You need to index in to it with {} instead of () to get the single string out as char.

fns{i}
teststruct.(fns{i})

Indexing in to it with () returns a 1-long cellstr array, which isn't the same format as the char array that the ".(name)" dynamic field reference wants. The formatting, especially in the display output, can be confusing. To see the difference, try this.

name_as_char = 'a'
name_as_cellstr = {'a'}

how to get the child node in div using javascript

var tds = document.getElementById("ctl00_ContentPlaceHolder1_Jobs_dlItems_ctl01_a").getElementsByTagName("td");
time = tds[0].firstChild.value;
address = tds[3].firstChild.value;

boto3 client NoRegionError: You must specify a region error only sometimes

For Python 2 I have found that the boto3 library does not source the region from the ~/.aws/config if the region is defined in a different profile to default. So you have to define it in the session creation.

session = boto3.Session(
    profile_name='NotDefault',
    region_name='ap-southeast-2'
)

print(session.available_profiles)

client = session.client(
    'ec2'
)

Where my ~/.aws/config file looks like this:

[default]
region=ap-southeast-2

[NotDefault]
region=ap-southeast-2

I do this because I use different profiles for different logins to AWS, Personal and Work.

Add new item in existing array in c#.net

Using a list would be your best option for memory management.

How to get the input from the Tkinter Text Widget?

Here is how I did it with python 3.5.2:

from tkinter import *
root=Tk()
def retrieve_input():
    inputValue=textBox.get("1.0","end-1c")
    print(inputValue)

textBox=Text(root, height=2, width=10)
textBox.pack()
buttonCommit=Button(root, height=1, width=10, text="Commit", 
                    command=lambda: retrieve_input())
#command=lambda: retrieve_input() >>> just means do this when i press the button
buttonCommit.pack()

mainloop()

with that, when i typed "blah blah" in the text widget and pressed the button, whatever i typed got printed out. So i think that is the answer for storing user input from Text widget to variable.

Linq code to select one item

These are the preferred methods:

var item = Items.SingleOrDefault(x => x.Id == 123);

Or

var item = Items.Single(x => x.Id == 123);

Invoking Java main method with parameters from Eclipse

Another idea:

Place all your parameters in a properties file (one parameter = one property in this file), then in your main method, load this file (using Properties.load(*fileInputStream*)). So if you want to modify one argument, you will just need to edit your args.properties file, and launch your application without more steps to do...

Of course, this is only for development purposes, but can be really helpfull if you have to change your arguments often...

Transform DateTime into simple Date in Ruby on Rails

For old Ruby (1.8.x):

myDate = Date.parse(myDateTime.to_s)

Android Studio suddenly cannot resolve symbols

I had a much stranger solution. In case anyone runs into this, it's worth double checking your gradle file. It turns out that as I was cloning this git and gradle was runnning, it deleted one line from my build.gradle (app) file.

dependencies {
     provided files(providedFiles)

Obviously the problem here was to just add it back and re-sync with gradle.

How to sign in kubernetes dashboard?

A self-explanatory simple one-liner to extract token for kubernetes dashboard login.

kubectl describe secret -n kube-system | grep deployment -A 12

Copy the token and paste it on the kubernetes dashboard under token sign in option and you are good to use kubernetes dashboard

How to make a gap between two DIV within the same column

You can make use of the first-child selector

<div class="sidebar">
    <div class="box">
        <p> 
            Text is here
         </p>
     </div>
    <div class="box">
        <p> 
            Text is here
         </p>
     </div>
</div>

and in CSS

.box {
    padding: 10px;
    text-align: justify;
    margin-top: 20px;
}
.box:first-child {
    margin-top: none;
}

Example: http://jsbin.com/ozarot/edit#javascript,html,live

How to insert TIMESTAMP into my MySQL table?

The DEFAULT value of a column in MySql is used only if it isn't provided a value for that column. So if you

INSERT INTO contactinfo (name, email, subject, date, comments)
VALUES ('$name', '$email', '$subject', '', '$comments')

You are not using the DEFAULT value for the column date, but you are providing an empty string, so you get an error, because you can't store an empty string in a DATETIME column. The same thing apply if you use NULL, because again NULL is a value. However, if you remove the column from the list of the column you are inserting, MySql will use the DEFAULT value specified for that column (or the data type default one)

How to get the python.exe location programmatically?

I think it depends on how you installed python. Note that you can have multiple installs of python, I do on my machine. However, if you install via an msi of a version of python 2.2 or above, I believe it creates a registry key like so:

HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows\CurrentVersion\App Paths\Python.exe

which gives this value on my machine:

C:\Python25\Python.exe

You just read the registry key to get the location.

However, you can install python via an xcopy like model that you can have in an arbitrary place, and you just have to know where it is installed.

Convert iterator to pointer?

The direct answer to your question is yes. If foo is a vector, you can do this: &foo[1].

This only works for vectors however, because the standard says that vectors implement storage by using contigious memory.

But you still can (and probably should) pass iterators instead of raw pointers because it is more expressive. Passing iterators does not make a copy of the vector.

The opposite of Intersect()

This code enumerates each sequence only once and uses Select(x => x) to hide the result to get a clean Linq-style extension method. Since it uses HashSet<T> its runtime is O(n + m) if the hashes are well distributed. Duplicate elements in either list are omitted.

public static IEnumerable<T> SymmetricExcept<T>(this IEnumerable<T> seq1,
    IEnumerable<T> seq2)
{
    HashSet<T> hashSet = new HashSet<T>(seq1);
    hashSet.SymmetricExceptWith(seq2);
    return hashSet.Select(x => x);
}

Create a 3D matrix

I use Octave, but Matlab has the same syntax.

Create 3d matrix:

octave:3> m = ones(2,3,2)
m =

ans(:,:,1) =

   1   1   1
   1   1   1

ans(:,:,2) =

   1   1   1
   1   1   1

Now, say I have a 2D matrix that I want to expand in a new dimension:

octave:4> Two_D = ones(2,3)
Two_D =
   1   1   1
   1   1   1

I can expand it by creating a 3D matrix, setting the first 2D in it to my old (here I have size two of the third dimension):

octave:11> Three_D = zeros(2,3,2)
Three_D =

ans(:,:,1) =

   0   0   0
   0   0   0

ans(:,:,2) =

   0   0   0
   0   0   0



octave:12> Three_D(:,:,1) = Two_D
Three_D =

ans(:,:,1) =

   1   1   1
   1   1   1

ans(:,:,2) =

   0   0   0
   0   0   0

How do I use Notepad++ (or other) with msysgit?

As of Git for Windows v2.15.0 (October 30th 2017) it is now possible to configure nano or Notepad++ as Git's default editor instead of vim.

During the installation you'll see the following screen:

enter image description here

What are the true benefits of ExpandoObject?

var obj = new Dictionary<string, object>;
...
Console.WriteLine(obj["MyString"]);

I think that only works because everything has a ToString(), otherwise you'd have to know the type that it was and cast the 'object' to that type.


Some of these are useful more often than others, I'm trying to be thorough.

  1. It may be far more natural to access a collection, in this case what is effectively a "dictionary", using the more direct dot notation.

  2. It seems as if this could be used as a really nice Tuple. You can still call your members "Item1", "Item2" etc... but now you don't have to, it's also mutable, unlike a Tuple. This does have the huge drawback of lack of intellisense support.

  3. You may be uncomfortable with "member names as strings", as is the feel with the dictionary, you may feel it is too like "executing strings", and it may lead to naming conventions getting coded in, and dealing with working with morphemes and syllables when code is trying understand how to use members :-P

  4. Can you assign a value to an ExpandoObject itself or just it's members? Compare and contrast with dynamic/dynamic[], use whichever best suits your needs.

  5. I don't think dynamic/dynamic[] works in a foreach loop, you have to use var, but possibly you can use ExpandoObject.

  6. You cannot use dynamic as a data member in a class, perhaps because it's at least sort of like a keyword, hopefully you can with ExpandoObject.

  7. I expect it "is" an ExpandoObject, might be useful to label very generic things apart, with code that differentiates based on types where there is lots of dynamic stuff being used.


Be nice if you could drill down multiple levels at once.

var e = new ExpandoObject();
e.position.x = 5;
etc...

Thats not the best possible example, imagine elegant uses as appropriate in your own projects.

It's a shame you cannot have code build some of these and push the results to intellisense. I'm not sure how this would work though.

Be nice if they could have a value as well as members.

var fifteen = new ExpandoObject();
fifteen = 15;
fifteen.tens = 1;
fifteen.units = 5;
fifteen.ToString() = "fifteen";
etc...

Test for array of string type in TypeScript

there is a little problem here because the

if (typeof item !== 'string') {
    return false
}

will not stop the foreach. So the function will return true even if the array does contain none string values.

This seems to wok for me:

function isStringArray(value: any): value is number[] {
  if (Object.prototype.toString.call(value) === '[object Array]') {
     if (value.length < 1) {
       return false;
     } else {
       return value.every((d: any) => typeof d === 'string');
     }
  }
  return false;
}

Greetings, Hans

Oracle client and networking components were not found

In my case this was because a file named ociw32.dll had been placed in c:\windows\system32. This is however only allowed to exist in c:\oracle\11.2.0.3\bin.

Deleting the file from system32, which had been placed there by an installation of Crystal Reports, fixed this issue

Python check if list items are integers?

You can use exceptional handling as str.digit will only work for integers and can fail for something like this too:

>>> str.isdigit(' 1')
False

Using a generator function:

def solve(lis):                                        
    for x in lis:
        try:
            yield float(x)
        except ValueError:    
            pass

>>> mylist = ['1','orange','2','3','4','apple', '1.5', '2.6']
>>> list(solve(mylist))                                    
[1.0, 2.0, 3.0, 4.0, 1.5, 2.6]   #returns converted values

or may be you wanted this:

def solve(lis):
    for x in lis:
        try:
            float(x)
            return True
        except:
            return False
...         
>>> mylist = ['1','orange','2','3','4','apple', '1.5', '2.6']
>>> [x for x in mylist if solve(x)]
['1', '2', '3', '4', '1.5', '2.6']

or using ast.literal_eval, this will work for all types of numbers:

>>> from ast import literal_eval
>>> def solve(lis):
    for x in lis:
        try:
            literal_eval(x)
            return True
        except ValueError:   
             return False
...         
>>> mylist=['1','orange','2','3','4','apple', '1.5', '2.6', '1+0j']
>>> [x for x in mylist if solve(x)]                               
['1', '2', '3', '4', '1.5', '2.6', '1+0j']

How do I correctly setup and teardown for my pytest class with tests?

As @Bruno suggested, using pytest fixtures is another solution that is accessible for both test classes or even just simple test functions. Here's an example testing python2.7 functions:

import pytest

@pytest.fixture(scope='function')
def some_resource(request):
    stuff_i_setup = ["I setup"]

    def some_teardown():
        stuff_i_setup[0] += " ... but now I'm torn down..."
        print stuff_i_setup[0]
    request.addfinalizer(some_teardown)

    return stuff_i_setup[0]

def test_1_that_needs_resource(some_resource):
    print some_resource + "... and now I'm testing things..."

So, running test_1... produces:

I setup... and now I'm testing things...
I setup ... but now I'm torn down...

Notice that stuff_i_setup is referenced in the fixture, allowing that object to be setup and torn down for the test it's interacting with. You can imagine this could be useful for a persistent object, such as a hypothetical database or some connection, that must be cleared before each test runs to keep them isolated.

What is the OR operator in an IF statement

OR is used as "||"

 if(expr1 || expr2)
 {
    do something
 }

Immutable vs Mutable types

A class is immutable if each object of that class has a fixed value upon instantiation that cannot SUBSEQUENTLY be changed

In another word change the entire value of that variable (name) or leave it alone.

Example:

my_string = "Hello world" 
my_string[0] = "h"
print my_string 

you expected this to work and print hello world but this will throw the following error:

Traceback (most recent call last):
File "test.py", line 4, in <module>
my_string[0] = "h"
TypeError: 'str' object does not support item assignment

The interpreter is saying : i can't change the first character of this string

you will have to change the whole string in order to make it works:

my_string = "Hello World" 
my_string = "hello world"
print my_string #hello world

check this table:

enter image description here

source

How to get cell value from DataGridView in VB.Net?

The line would be as shown below:

Dim x As Integer    
x = dgvName.Rows(yourRowIndex).Cells(yourColumnIndex).Value

Import local function from a module housed in another directory with relative imports in Jupyter Notebook using Python 3

Here's my 2 cents:

import sys

map the path where the module file is located. In my case it was the desktop

sys.path.append('/Users/John/Desktop')

Either import the whole mapping module BUT then you have to use the .notation to map the classes like mapping.Shipping()

import mapping #mapping.py is the name of my module file

shipit = mapping.Shipment() #Shipment is the name of the class I need to use in the mapping module

Or import the specific class from the mapping module

from mapping import Mapping

shipit = Shipment() #Now you don't have to use the .notation

Remove ':hover' CSS behavior from element

I would use two classes. Keep your test class and add a second class called testhover which you only add to those you want to hover - alongside the test class. This isn't directly what you asked but without more context it feels like the best solution and is possibly the cleanest and simplest way of doing it.

Example:

_x000D_
_x000D_
.test {  border: 0px; }_x000D_
.testhover:hover {  border: 1px solid red; }
_x000D_
<div class="test"> blah </div>_x000D_
<div class="test"> blah </div>_x000D_
<div class="test testhover"> blah </div>
_x000D_
_x000D_
_x000D_

How can I create a simple index.html file which lists all files/directories?

There's a free php script made by Celeron Dude that can do this called Celeron Dude Indexer 2. It doesn't require .htaccess The source code is easy to understand and provides a good starting point.

Here's a download link: https://gitlab.com/desbest/celeron-dude-indexer/

celeron dude indexer

Why am I getting "Cannot Connect to Server - A network-related or instance-specific error"?

It could also be as simple as the fact that your database is not actually MS SQL Server. If your database is actually MySql, for instance, and you try to connect to it with System.Data.SqlClient you will get this error.

By far most examples of ADO.Net will be for MSSQL and the inexperienced user may not know that you can't use SqlConnection, SqlCommand, etc., with MySql.

While all ADO.Net data providers conform to the same interface, you have to use the provider made for your database.

Maven in Eclipse: step by step installation

IF you want to install Maven in Eclipse(Java EE) Indigo Then follow these Steps :

  1. Eclipse -> Help -> Install New Software.

  2. Type " http://download.eclipse.org/releases/indigo/ " & Hit Enter.

  3. Expand " Collaboration " tag.

  4. Select Maven plugin from there.

  5. Click on next .

  6. Accept the agreement & click finish.

After installing the maven it will ask for restarting the Eclipse,So restart the eclipse again to see the changes.

file_get_contents behind a proxy?

There's a similar post here: http://techpad.co.uk/content.php?sid=137 which explains how to do it.

function file_get_contents_proxy($url,$proxy){

    // Create context stream
    $context_array = array('http'=>array('proxy'=>$proxy,'request_fulluri'=>true));
    $context = stream_context_create($context_array);

    // Use context stream with file_get_contents
    $data = file_get_contents($url,false,$context);

    // Return data via proxy
    return $data;

}

How to install Visual Studio 2015 on a different drive

Run the installer from command line with argument /CustomInstallPath InstallationDirectory

See more command-line parameters and other installation information.

Note: this won't change location of all files, but only of those which can be (by design) installed onto different location. Be warned that there is many shared components which will be installed into shared repositories on drive C: without any possibility to change their path (unless you do some hacking using mklink /j (directory junction, i.e."hard link for folder"), but it is questionable whether it is worth it, because any Visual Studio updates will break those hard links. This is confirmed by people who tried that, although on Visual Studio 2012.)


Update: per recent comment, uninstallation of Visual Studio might be required before the above applies. Uninstallation command is like this: vs_community_ENU.exe /uninstall /force

passing argument to DialogFragment

Just that i want to show how to do what do said @JafarKhQ in Kotlin for those who use kotlin that might help them and save theme time too:

so you have to create a companion objet to create new newInstance function

you can set the paremter of the function whatever you want. using

 val args = Bundle()

you can set your args.

You can now use args.putSomthing to add you args which u give as a prameter in your newInstance function. putString(key:String,str:String) to add string for example and so on

Now to get the argument you can use arguments.getSomthing(Key:String)=> like arguments.getString("1")

here is a full example

class IntervModifFragment : DialogFragment(), ModContract.View
{
    companion object {
        fun newInstance(  plom:String,type:String,position: Int):IntervModifFragment {
            val fragment =IntervModifFragment()
            val args = Bundle()
            args.putString( "1",plom)
            args.putString("2",type)
            args.putInt("3",position)
            fragment.arguments = args
            return fragment
        }
    }

...
    override fun onViewCreated(view: View?, savedInstanceState: Bundle?) {
        super.onViewCreated(view, savedInstanceState)
        fillSpinerPlom(view,arguments.getString("1"))
         fillSpinerType(view, arguments.getString("2"))
        confirmer_virme.setOnClickListener({on_confirmClick( arguments.getInt("3"))})


        val dateSetListener = object : DatePickerDialog.OnDateSetListener {
            override fun onDateSet(view: DatePicker, year: Int, monthOfYear: Int,
                                   dayOfMonth: Int) {
                val datep= DateT(year,monthOfYear,dayOfMonth)
                updateDateInView(datep.date)
            }
        }

    }
  ...
}

Now how to create your dialog you can do somthing like this in another class

  val dialog = IntervModifFragment.newInstance(ListInter.list[position].plom,ListInter.list[position].type,position)

like this for example

class InterListAdapter(private val context: Context, linkedList: LinkedList<InterItem> ) : RecyclerView.Adapter<InterListAdapter.ViewHolder>()
{
   ... 
    override fun onBindViewHolder(holder: ViewHolder, position: Int) {

        ...
        holder.btn_update!!.setOnClickListener {
           val dialog = IntervModifFragment.newInstance(ListInter.list[position].plom,ListInter.list[position].type,position)
           val ft = (context as AppCompatActivity).supportFragmentManager.beginTransaction()
            dialog.show(ft, ContentValues.TAG)
        }
        ...
    }
..

}

how to remove multiple columns in r dataframe?

@Ahmed Elmahy following approach should help you out, when you have got a vector of column names you want to remove from your dataframe:

test_df <- data.frame(col1 = c("a", "b", "c", "d", "e"), col2 = seq(1, 5), col3 = rep(3, 5))
rm_col <- c("col2")
test_df[, !(colnames(test_df) %in% rm_col), drop = FALSE]

All the best, ExploreR

Declaring and using MySQL varchar variables

I ran into the same problem using MySQL Workbench. According to the MySQL documentation, the DECLARE "statement declares local variables within stored programs." That apparently means it is only guaranteed to work with stored procedures/functions.

The solution for me was to simply remove the DECLARE statement, and introduce the variable in the SET statement. For your code that would mean:

-- DECLARE FOO varchar(7); 
-- DECLARE oldFOO varchar(7);

-- the @ symbol is required
SET @FOO = '138'; 
SET @oldFOO = CONCAT('0', FOO);

UPDATE mypermits SET person = FOO WHERE person = oldFOO;

What is a "cache-friendly" code?

It needs to be clarified that not only data should be cache-friendly, it is just as important for the code. This is in addition to branch predicition, instruction reordering, avoiding actual divisions and other techniques.

Typically the denser the code, the fewer cache lines will be required to store it. This results in more cache lines being available for data.

The code should not call functions all over the place as they typically will require one or more cache lines of their own, resulting in fewer cache lines for data.

A function should begin at a cache line-alignment-friendly address. Though there are (gcc) compiler switches for this be aware that if the the functions are very short it might be wasteful for each one to occupy an entire cache line. For example, if three of the most often used functions fit inside one 64 byte cache line, this is less wasteful than if each one has its own line and results in two cache lines less available for other usage. A typical alignment value could be 32 or 16.

So spend some extra time to make the code dense. Test different constructs, compile and review the generated code size and profile.

jQuery DIV click, with anchors

I know that if you were to change that to an href you'd do:

$("a#link1").click(function(event) {
  event.preventDefault();
  $('div.link1').show();
  //whatever else you want to do
});

so if you want to keep it with the div, I'd try

$("div.clickable").click(function(event) {
  event.preventDefault();
  window.location = $(this).attr("url");
});

Bootstrap: How to center align content inside column?

You can do this by adding a div i.e. centerBlock. And give this property in CSS to center the image or any content. Here is the code:

<div class="container">
    <div class="row">
        <div class="col-sm-4 col-md-4 col-lg-4">
            <div class="centerBlock">
                <img class="img-responsive" src="img/some-image.png" title="This image needs to be centered">
            </div>
        </div>
        <div class="col-sm-8 col-md-8 col-lg-8">
            Some content not important at this moment
        </div>
    </div>
</div>


// CSS

.centerBlock {
  display: table;
  margin: auto;
}

How to get a user's client IP address in ASP.NET?

Hello guys Most of the codes you will find will return you server ip address not client ip address .however this code returns correct client ip address.Give it a try. For More info just check this

https://www.youtube.com/watch?v=Nkf37DsxYjI

for getting your local ip address using javascript you can use put this code inside your script tag

<script>
    var RTCPeerConnection = /*window.RTCPeerConnection ||*/
     window.webkitRTCPeerConnection || window.mozRTCPeerConnection;

         if (RTCPeerConnection) (function () {
             var rtc = new RTCPeerConnection({ iceServers: [] });
             if (1 || window.mozRTCPeerConnection) {      
                 rtc.createDataChannel('', { reliable: false });
             };

             rtc.onicecandidate = function (evt) {

                 if (evt.candidate)
                     grepSDP("a=" + evt.candidate.candidate);
             };
             rtc.createOffer(function (offerDesc) {
                 grepSDP(offerDesc.sdp);
                 rtc.setLocalDescription(offerDesc);
             }, function (e) { console.warn("offer failed", e); });


             var addrs = Object.create(null);
             addrs["0.0.0.0"] = false;
             function updateDisplay(newAddr) {
                 if (newAddr in addrs) return;
                 else addrs[newAddr] = true;
                 var displayAddrs = Object.keys(addrs).filter(function
(k) { return addrs[k]; });
                 document.getElementById('list').textContent =
displayAddrs.join(" or perhaps ") || "n/a";
             }

             function grepSDP(sdp) {
                 var hosts = [];
                 sdp.split('\r\n').forEach(function (line) { 
                     if (~line.indexOf("a=candidate")) {   
                         var parts = line.split(' '),   
                             addr = parts[4],
                             type = parts[7];
                         if (type === 'host') updateDisplay(addr);
                     } else if (~line.indexOf("c=")) {      
                         var parts = line.split(' '),
                             addr = parts[2];
                         updateDisplay(addr);
                     }
                 });
             }
         })(); else
         {
             document.getElementById('list').innerHTML = "<code>ifconfig| grep inet | grep -v inet6 | cut -d\" \" -f2 | tail -n1</code>";
             document.getElementById('list').nextSibling.textContent = "In Chrome and Firefox your IP should display automatically, by the power of WebRTCskull.";

         }




</script>
<body>
<div id="list"></div>
</body>

and For getting your public ip address you can use put this code inside your script tag

  function getIP(json) {
    document.write("My public IP address is: ", json.ip);
  }


<script type="application/javascript" src="https://api.ipify.org?format=jsonp&callback=getIP"></script>

How do I debug "Error: spawn ENOENT" on node.js?

Although it may be an environment path or another issue for some people, I had just installed the Latex Workshop extension for Visual Studio Code on Windows 10 and saw this error when attempting to build/preview the PDF. Running VS Code as Administrator solved the problem for me.

MySQL - sum column value(s) based on row from the same table

SUM CASE using example:

    SELECT 
  DISTINCT(p.`ProductID`) AS ProductID,
  SUM(IF(p.`PaymentMethod`='Cash',Amount,0)) AS Cash_,
  SUM(IF(p.`PaymentMethod`='Check',Amount,0)) AS Check_,
  SUM(IF(p.`PaymentMethod`='Credit Card',Amount,0)) AS Credit_Card_,
  SUM( CASE PaymentMethod 
      WHEN 'Cash' THEN Amount
      WHEN 'Check' THEN Amount
      WHEN 'Credit Card' THEN Amount
     END) AS Total
FROM
  `payments` AS p 
GROUP BY p.`ProductID`;

SQL FIDDLE: http://www.sqlfiddle.com/#!9/23d07d/18

Result and Table view

How can I generate an ObjectId with mongoose?

You can create a new MongoDB ObjectId like this using mongoose:

var mongoose = require('mongoose');
var newId = new mongoose.mongo.ObjectId('56cb91bdc3464f14678934ca');
// or leave the id string blank to generate an id with a new hex identifier
var newId2 = new mongoose.mongo.ObjectId();

Date in to UTC format Java

Try to format your date with the Z or z timezone flags:

new SimpleDateFormat("MM/dd/yyyy KK:mm:ss a Z").format(dateObj);

How to show the text on a ImageButton?

ImageButton can't have text (or, at least, android:text isn't listed in its attributes).

The Trick is:

It looks like you need to use Button (and look at drawableTop or setCompoundDrawablesWithIntrinsicBounds(int,int,int,int)).

Get month name from Date

You can try this:

var d = new Date();
var t = d.toDateString().split(" ");
t[2] +" "+t[1]+" "+t[3];

Why doesn't indexOf work on an array IE8?

You can use this to replace the function if it doesn't exist:

<script>
if (!Array.prototype.indexOf) {
    Array.prototype.indexOf = function(elt /*, from*/) {
        var len = this.length >>> 0;

        var from = Number(arguments[1]) || 0;
        from = (from < 0) ? Math.ceil(from) : Math.floor(from);
        if (from < 0)
            from += len;

        for (; from < len; from++) {
            if (from in this && this[from] === elt)
                return from;
        }
        return -1;
    };
}
</script>

How to change root logging level programmatically for logback

I assume you are using logback (from the configuration file).

From logback manual, I see

Logger rootLogger = LoggerFactory.getLogger(org.slf4j.Logger.ROOT_LOGGER_NAME);

Perhaps this can help you change the value?

Can I force a UITableView to hide the separator between empty cells?

Using the link from Daniel, I made an extension to make it more usable:

//UITableViewController+Ext.m
- (void)hideEmptySeparators
{
    UIView *v = [[UIView alloc] initWithFrame:CGRectZero];
    v.backgroundColor = [UIColor clearColor];
    [self.tableView setTableFooterView:v];
    [v release];
}

After some testings, I found out that the size can be 0 and it works as well. So it doesn't add some kind of margin at the end of the table. So thanks wkw for this hack. I decided to post that here since I don't like redirect.

How can I fix the 'Missing Cross-Origin Resource Sharing (CORS) Response Header' webfont issue?

If you are just interested in the use of Access-Control-Allow-Origin:*

You can do that with this .htaccess file at the site root.

Header set Access-Control-Allow-Origin "*"

Some useful information here: http://enable-cors.org/server_apache.html

How can you create multiple cursors in Visual Studio Code

On Ubuntu, in order to enable multi-cursor clicking you will need to re-assign Alt+click first, by running the command below. This is because by default Ubuntu uses the shortcut itself and has it takes precedence.

> gsettings set org.gnome.desktop.wm.preferences mouse-button-modifier "<Super>"

How to remove only 0 (Zero) values from column in excel 2010

The easiest way of all is as follows: Click the office button (top left) Click "Excel Options" Click "Advanced" Scroll down to "Display options for this worksheet" Untick the box "Show a zero in cells that have zero value" Click "okay"

That's all there is to it.

:)

Change border color on <select> HTML form

As Diodeus stated, IE doesn't allow anything but the default border for <select> elements. However, I know of two hacks to achieve a similar effect :

  1. Use a DIV that is placed absolutely at the same position as the dropdown and set it's borders. It will appear that the dropdown has a border.

  2. Use a Javascript solution, for instance, the one provided here.

It may however prove to be too much effort, so you should evaluate if you really require the border.

How to add a constant column in a Spark DataFrame?

In spark 2.2 there are two ways to add constant value in a column in DataFrame:

1) Using lit

2) Using typedLit.

The difference between the two is that typedLit can also handle parameterized scala types e.g. List, Seq, and Map

Sample DataFrame:

val df = spark.createDataFrame(Seq((0,"a"),(1,"b"),(2,"c"))).toDF("id", "col1")

+---+----+
| id|col1|
+---+----+
|  0|   a|
|  1|   b|
+---+----+

1) Using lit: Adding constant string value in new column named newcol:

import org.apache.spark.sql.functions.lit
val newdf = df.withColumn("newcol",lit("myval"))

Result:

+---+----+------+
| id|col1|newcol|
+---+----+------+
|  0|   a| myval|
|  1|   b| myval|
+---+----+------+

2) Using typedLit:

import org.apache.spark.sql.functions.typedLit
df.withColumn("newcol", typedLit(("sample", 10, .044)))

Result:

+---+----+-----------------+
| id|col1|           newcol|
+---+----+-----------------+
|  0|   a|[sample,10,0.044]|
|  1|   b|[sample,10,0.044]|
|  2|   c|[sample,10,0.044]|
+---+----+-----------------+

How do I disable a jquery-ui draggable?

Change draggable attribute from

<span draggable="true">Label</span>

to

<span draggable="false">Label</span>

Fastest Convert from Collection to List<T>

As long as ManagementObjectCollection implements IEnumerable<ManagementObject> you can do:

List<ManagementObject> managementList = new List<ManagementObjec>(managementObjects);

If it doesn't, then you are stuck doing it the way that you are doing it.

Inconsistent accessibility: property type is less accessible

Your class Delivery has no access modifier, which means it defaults to internal. If you then try to expose a property of that type as public, it won't work. Your type (class) needs to have the same, or higher access as your property.

More about access modifiers: http://msdn.microsoft.com/en-us/library/ms173121.aspx

Get event listeners attached to node using addEventListener

You can't.

The only way to get a list of all event listeners attached to a node is to intercept the listener attachment call.

DOM4 addEventListener

Says

Append an event listener to the associated list of event listeners with type set to type, listener set to listener, and capture set to capture, unless there already is an event listener in that list with the same type, listener, and capture.

Meaning that an event listener is added to the "list of event listeners". That's all. There is no notion of what this list should be nor how you should access it.

Decompile Python 2.7 .pyc

In case anyone is still struggling with this, as I was all morning today, I have found a solution that works for me:

Uncompyle

Installation instructions:

git clone https://github.com/gstarnberger/uncompyle.git
cd uncompyle/
sudo ./setup.py install

Once the program is installed (note: it will be installed to your system-wide-accessible Python packages, so it should be in your $PATH), you can recover your Python files like so:

uncompyler.py thank_goodness_this_still_exists.pyc > recovered_file.py

The decompiler adds some noise mostly in the form of comments, however I've found it to be surprisingly clean and faithful to my original code. You will have to remove a little line of text beginning with +++ near the end of the recovered file to be able to run your code.

How to get a specific column value from a DataTable in c#

The table normally contains multiple rows. Use a loop and use row.Field<string>(0) to access the value of each row.

foreach(DataRow row in dt.Rows)
{
    string file = row.Field<string>("File");
}

You can also access it via index:

foreach(DataRow row in dt.Rows)
{
    string file = row.Field<string>(0);
}

If you expect only one row, you can also use the indexer of DataRowCollection:

string file = dt.Rows[0].Field<string>(0); 

Since this fails if the table is empty, use dt.Rows.Count to check if there is a row:

if(dt.Rows.Count > 0)
    file = dt.Rows[0].Field<string>(0);

Conda command not found

I faced this issue on my mac after updating conda. Solution was to run conda mini installer on top of existing conda setup.

$ curl https://repo.continuum.io/miniconda/Miniconda3-latest-MacOSX-x86_64.sh -o ~/miniconda3.sh
$ bash ~/miniconda3.sh -bfp ~/miniconda3

On linux, you can use:

$ curl https://repo.continuum.io/miniconda/Miniconda3-latest-Linux-x86_64.sh -o ~/miniconda3.sh
$ bash ~/miniconda3.sh -bfp ~/miniconda3

For other versions, you can go to https://repo.continuum.io/miniconda/

For details check: https://github.com/conda/conda/issues/1364

Delete a row in DataGridView Control in VB.NET

Assuming you are using Windows forms, you could allow the user to select a row and in the delete key click event. It is recommended that you allow the user to select 1 row only and not a group of rows (myDataGridView.MultiSelect = false)

Private Sub pbtnDelete_Click(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles btnDelete.Click

        If myDataGridView.SelectedRows.Count > 0 Then
            'you may want to add a confirmation message, and if the user confirms delete
            myDataGridView.Rows.Remove(myDataGridView.SelectedRows(0))
        Else
            MessageBox.Show("Select 1 row before you hit Delete")
        End If

    End Sub

Note that this will not delete the row form the database until you perform the delete in the database.

NameError: name 'reduce' is not defined in Python

In this case I believe that the following is equivalent:

l = sum([1,2,3,4]) % 2

The only problem with this is that it creates big numbers, but maybe that is better than repeated modulo operations?

Rotate axis text in python matplotlib

Easy way

As described here, there is an existing method in the matplotlib.pyplot figure class that automatically rotates dates appropriately for you figure.

You can call it after you plot your data (i.e.ax.plot(dates,ydata) :

fig.autofmt_xdate()

If you need to format the labels further, checkout the above link.

Non-datetime objects

As per languitar's comment, the method I suggested for non-datetime xticks would not update correctly when zooming, etc. If it's not a datetime object used as your x-axis data, you should follow Tommy's answer:

for tick in ax.get_xticklabels():
    tick.set_rotation(45)

copy-item With Alternate Credentials

Here's my script that runs as LocalSystem on a machine, but needs credentials of a domaim user to access a network file location. It allows you to store the user's password in a "safe-ish" encrypted file; that can only be read by the user that wrote it.

Setting and changing the password is done by copying a file with the plaintext password in it to the machine. When the script is next run it reads the password, encrypts it, then deletes the plaintext password.

$plaintext_password_file = 'C:\plaintext.txt' # Stores the password in plain text - only used once, then deleted
$encryted_password_file = 'C:\copy_pass.txt'  # Stores the password in "safe" encrypted form - used for subsequent runs of the script
                                              #   - can only be decrypted by the windows user that wrote it
$file_copy_user = 'OURDOMAIN\A_User'

# Check to see if there is a new plaintext password
if (Test-Path $plaintext_password_file)
{
    # Read in plaintext password, convert to a secure-string, convert to an encrypted-string, and write out, for use later
    get-content $plaintext_password_file | convertto-securestring -asplaintext -force | convertfrom-securestring | out-file $encryted_password_file
    # Now we have encrypted password, remove plain text for safety
    Remove-Item $plaintext_password_file
}


# Read in the encrypted password, convert to a secure-string
$pass = get-content $encryted_password_file | convertto-securestring

# create a credential object for the other user, using username and password stored in secure-string
$credentials = new-object -typename System.Management.Automation.PSCredential -argumentlist $file_copy_user,$pass

# Connect to network file location as the other user and map to drive J:
New-PSDrive -Name J -PSProvider FileSystem -Root "\\network\file_directory" -Credential $credentials

# Copy the file to J:
Copy-Item -Force -Verbose -Path "C:\a_file.txt" -Destination "J:\"

As an extra refinement: The username could also be encrypted as well, rather than hardcoded.

Giving a border to an HTML table row, <tr>

After fighting with this for a long time I have concluded that the spectacularly simple answer is to just fill the table with empty cells to pad out every row of the table to the same number of cells (taking colspan into account, obviously). With computer-generated HTML this is very simple to arrange, and avoids fighting with complex workarounds. Illustration follows:

<h3>Table borders belong to cells, and aren't present if there is no cell</h3>
<table style="border:1px solid red; width:100%; border-collapse:collapse;">
    <tr style="border-top:1px solid darkblue;">
        <th>Col 1<th>Col 2<th>Col 3
    <tr style="border-top:1px solid darkblue;">
        <td>Col 1 only
    <tr style="border-top:1px solid darkblue;">
        <td colspan=2>Col 1 2 only
    <tr style="border-top:1px solid darkblue;">
        <td>1<td>2<td>3

</table>


<h3>Simple solution, artificially insert empty cells</h3>

<table style="border:1px solid red; width:100%; border-collapse:collapse;">
    <tr style="border-top:1px solid darkblue;">
        <th>Col 1<th>Col 2<th>Col 3
    <tr style="border-top:1px solid darkblue;">
        <td>Col 1 only<td><td>
    <tr style="border-top:1px solid darkblue;">
        <td colspan=2>Col 1 2 only<td>
    <tr style="border-top:1px solid darkblue;">
        <td>1<td>2<td>3

</table>

How to open a file / browse dialog using javascript?

Here's is a way of doing it without any Javascript and it's also compatible with any browser.


EDIT: In Safari, the input gets disabled when hidden with display: none. A better approach would be to use position: fixed; top: -100em.


<label>
  Open file dialog
  <input type="file" style="position: fixed; top: -100em">
</label>

Also, if you prefer you can go the "correct way" by using for in the label pointing to the id of the input like this:

<label for="inputId">file dialog</label>
<input id="inputId" type="file" style="position: fixed; top: -100em">

Getting first value from map in C++

begin() returns the first pair, (precisely, an iterator to the first pair, and you can access the key/value as ->first and ->second of that iterator)

Finding Key associated with max Value in a Java Map

This code will print all the keys with maximum value

public class NewClass4 {
    public static void main(String[] args)
    {
        HashMap<Integer,Integer>map=new HashMap<Integer, Integer>();
        map.put(1, 50);
        map.put(2, 60);
        map.put(3, 30);
        map.put(4, 60);
        map.put(5, 60);
        int maxValueInMap=(Collections.max(map.values()));  // This will return max value in the Hashmap
        for (Entry<Integer, Integer> entry : map.entrySet()) {  // Itrate through hashmap
            if (entry.getValue()==maxValueInMap) {
                System.out.println(entry.getKey());     // Print the key with max value
            }
        }

    }
}

How to delete Certain Characters in a excel 2010 cell

If [John Smith] is in cell A1, then use this formula to do what you want:

=SUBSTITUTE(SUBSTITUTE(A1, "[", ""), "]", "")

The inner SUBSTITUTE replaces all instances of "[" with "" and returns a new string, then the other SUBSTITUTE replaces all instances of "]" with "" and returns the final result.

Angular 2 two way binding using ngModel is not working

As per Angular2 final, you do not even have to import FORM_DIRECTIVES as suggested above by many. However, the syntax has been changed as kebab-case was dropped for the betterment.

Just replace ng-model with ngModel and wrap it in a box of bananas. But you have spilt the code into two files now:

app.ts:

import { Component } from '@angular/core';

@Component({
  selector: 'ng-app',
  template: `
    <input id="name" type="text" [(ngModel)]="name"  />
    {{ name }}
  `
})
export class DataBindingComponent {
  name: string;

  constructor() {
    this.name = 'Jose';
  }
}

app.module.ts:

import { NgModule } from '@angular/core';
import { FormsModule } from '@angular/forms';
import { BrowserModule } from '@angular/platform-browser';
import { platformBrowserDynamic } from '@angular/platform-browser-dynamic';
import { DataBindingComponent } from './app'; //app.ts above

@NgModule({
  declarations: [DataBindingComponent],
  imports:      [BrowserModule, FormsModule],
  bootstrap:    [DataBindingComponent]
})
export default class MyAppModule {}

platformBrowserDynamic().bootstrapModule(MyAppModule);

How do I escape a single quote ( ' ) in JavaScript?

You can escape a ' in JavaScript like \'

Javascript wait() function

You shouldn't edit it, you should completely scrap it.

Any attempt to make execution stop for a certain amount of time will lock up the browser and switch it to a Not Responding state. The only thing you can do is use setTimeout correctly.

How to perform element-wise multiplication of two lists?

gahooa's answer is correct for the question as phrased in the heading, but if the lists are already numpy format or larger than ten it will be MUCH faster (3 orders of magnitude) as well as more readable, to do simple numpy multiplication as suggested by NPE. I get these timings:

0.0049ms -> N = 4, a = [i for i in range(N)], c = [a*b for a,b in zip(a, b)]
0.0075ms -> N = 4, a = [i for i in range(N)], c = a * b
0.0167ms -> N = 4, a = np.arange(N), c = [a*b for a,b in zip(a, b)]
0.0013ms -> N = 4, a = np.arange(N), c = a * b
0.0171ms -> N = 40, a = [i for i in range(N)], c = [a*b for a,b in zip(a, b)]
0.0095ms -> N = 40, a = [i for i in range(N)], c = a * b
0.1077ms -> N = 40, a = np.arange(N), c = [a*b for a,b in zip(a, b)]
0.0013ms -> N = 40, a = np.arange(N), c = a * b
0.1485ms -> N = 400, a = [i for i in range(N)], c = [a*b for a,b in zip(a, b)]
0.0397ms -> N = 400, a = [i for i in range(N)], c = a * b
1.0348ms -> N = 400, a = np.arange(N), c = [a*b for a,b in zip(a, b)]
0.0020ms -> N = 400, a = np.arange(N), c = a * b

i.e. from the following test program.

import timeit

init = ['''
import numpy as np
N = {}
a = {}
b = np.linspace(0.0, 0.5, len(a))
'''.format(i, j) for i in [4, 40, 400] 
                  for j in ['[i for i in range(N)]', 'np.arange(N)']]

func = ['''c = [a*b for a,b in zip(a, b)]''',
'''c = a * b''']

for i in init:
  for f in func:
    lines = i.split('\n')
    print('{:6.4f}ms -> {}, {}, {}'.format(
           timeit.timeit(f, setup=i, number=1000), lines[2], lines[3], f))

How can I modify the size of column in a MySQL table?

ALTER TABLE <tablename> CHANGE COLUMN <colname> <colname> VARCHAR(65536);

You have to list the column name twice, even if you aren't changing its name.

Note that after you make this change, the data type of the column will be MEDIUMTEXT.


Miky D is correct, the MODIFY command can do this more concisely.


Re the MEDIUMTEXT thing: a MySQL row can be only 65535 bytes (not counting BLOB/TEXT columns). If you try to change a column to be too large, making the total size of the row 65536 or greater, you may get an error. If you try to declare a column of VARCHAR(65536) then it's too large even if it's the only column in that table, so MySQL automatically converts it to a MEDIUMTEXT data type.

mysql> create table foo (str varchar(300));
mysql> alter table foo modify str varchar(65536);
mysql> show create table foo;
CREATE TABLE `foo` (
  `str` mediumtext
) ENGINE=MyISAM DEFAULT CHARSET=latin1
1 row in set (0.00 sec)

I misread your original question, you want VARCHAR(65353), which MySQL can do, as long as that column size summed with the other columns in the table doesn't exceed 65535.

mysql> create table foo (str1 varchar(300), str2 varchar(300));
mysql> alter table foo modify str2 varchar(65353);
ERROR 1118 (42000): Row size too large. 
The maximum row size for the used table type, not counting BLOBs, is 65535. 
You have to change some columns to TEXT or BLOBs

String replacement in java, similar to a velocity template

Take a look at the java.text.MessageFormat class, MessageFormat takes a set of objects, formats them, then inserts the formatted strings into the pattern at the appropriate places.

Object[] params = new Object[]{"hello", "!"};
String msg = MessageFormat.format("{0} world {1}", params);

Highcharts - redraw() vs. new Highcharts.chart

var newData = [1,2,3,4,5,6,7];
var chart = $('#chartjs').highcharts();
chart.series[0].setData(newData, true);

Explanation:
Variable newData contains value that want to update in chart. Variable chart is an object of a chart. setData is a method provided by highchart to update data.

Method setData contains two parameters, in first parameter we need to pass new value as array and second param is Boolean value. If true then chart updates itself and if false then we have to use redraw() method to update chart (i.e chart.redraw();)

http://jsfiddle.net/NxEnH/8/

How to combine GROUP BY, ORDER BY and HAVING

Your code should be contain WHILE before group by and having :

SELECT Email, COUNT(*)

FROM user_log

WHILE Email IS NOT NULL

GROUP BY Email

HAVING COUNT(*) > 1

ORDER BY UpdateDate DESC

How to auto-size an iFrame?

Actually - Patrick's code sort of worked for me as well. The correct way to do it would be along the lines of this:

Note: there's a bit of jquery ahead:


if ($.browser.msie == false) {
    var h = (document.getElementById("iframeID").contentDocument.body.offsetHeight);
} else {
    var h = (document.getElementById("iframeID").Document.body.scrollHeight);
}

Increase bootstrap dropdown menu width

Text will never wrap to the next line. The text continues on the same line until a
tag is encountered.

.dropdown-menu {
    white-space: nowrap;
}

AddTransient, AddScoped and AddSingleton Services Differences

This image illustrates this concept well. Unfortunately, I could not find the original source of this image, but someone made it, he has shown this concept very well in the form of an image. enter image description here

Finding the next available id in MySQL

Given what you said in a comment:

my id coloumn is auto increment i have to get the id and convert it to another base.So i need to get the next id before insert cause converted code will be inserted too.

There is a way to do what you're asking, which is to ask the table what the next inserted row's id will be before you actually insert:

SHOW TABLE STATUS WHERE name = "myTable"

there will be a field in that result set called "Auto_increment" which tells you the next auto increment value.

SQL Server database restore error: specified cast is not valid. (SqlManagerUI)

Below can be 2 reasons for this issue:

  1. Backup taken on SQL 2012 and Restore Headeronly was done in SQL 2008 R2

  2. Backup media is corrupted.

If we run below command, we can find actual error always:

restore headeronly
from disk = 'C:\Users\Public\Database.bak'

Give complete location of your database file in the quot

Hope it helps

Does a "Find in project..." feature exist in Eclipse IDE?

There is no way to do pure text search in whole work workspace/project via a shortcut that I know of (and it is a PITA), but this will find references in the workspace:

  1. Put your cursor on what you want to lookup
  2. Press Ctrl + Shift + g

Difference between __getattr__ vs __getattribute__

New-style classes are ones that subclass "object" (directly or indirectly). They have a __new__ class method in addition to __init__ and have somewhat more rational low-level behavior.

Usually, you'll want to override __getattr__ (if you're overriding either), otherwise you'll have a hard time supporting "self.foo" syntax within your methods.

Extra info: http://www.devx.com/opensource/Article/31482/0/page/4

react hooks useEffect() cleanup for only componentWillUnmount?

useEffect are isolated within its own scope and gets rendered accordingly. Image from https://reactjs.org/docs/hooks-custom.html

enter image description here

How do I start an activity from within a Fragment?

The difference between starting an Activity from a Fragment and an Activity is how you get the context, because in both cases it has to be an activity.

From an activity: The context is the current activity (this)

Intent intent = new Intent(this, NewActivity.class);
startActivity(intent);

From a fragment: The context is the parent activity (getActivity()). Notice, that the fragment itself can start the activity via startActivity(), this is not necessary to be done from the activity.

Intent intent = new Intent(getActivity(), NewActivity.class);
startActivity(intent);

'numpy.ndarray' object is not callable error

The error TypeError: 'numpy.ndarray' object is not callable means that you tried to call a numpy array as a function. We can reproduce the error like so in the repl:

In [16]: import numpy as np

In [17]: np.array([1,2,3])()
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/home/user/<ipython-input-17-1abf8f3c8162> in <module>()
----> 1 np.array([1,2,3])()

TypeError: 'numpy.ndarray' object is not callable

If we are to assume that the error is indeed coming from the snippet of code that you posted (something that you should check,) then you must have reassigned either pd.rolling_mean or pd.rolling_std to a numpy array earlier in your code.

What I mean is something like this:

In [1]: import numpy as np

In [2]: import pandas as pd

In [3]: pd.rolling_mean(np.array([1,2,3]), 20, min_periods=5) # Works
Out[3]: array([ nan,  nan,  nan])

In [4]: pd.rolling_mean = np.array([1,2,3])

In [5]: pd.rolling_mean(np.array([1,2,3]), 20, min_periods=5) # Doesn't work anymore...
---------------------------------------------------------------------------
TypeError                                 Traceback (most recent call last)
/home/user/<ipython-input-5-f528129299b9> in <module>()
----> 1 pd.rolling_mean(np.array([1,2,3]), 20, min_periods=5) # Doesn't work anymore...

TypeError: 'numpy.ndarray' object is not callable

So, basically you need to search the rest of your codebase for pd.rolling_mean = ... and/or pd.rolling_std = ... to see where you may have overwritten them.


Also, if you'd like, you can put in reload(pd) just before your snippet, which should make it run by restoring the value of pd to what you originally imported it as, but I still highly recommend that you try to find where you may have reassigned the given functions.

Select N random elements from a List<T> in C#

Using linq:

YourList.OrderBy(x => rnd.Next()).Take(5)

Concatenating strings in C, which method is more efficient?

For readability, I'd go with

char * s = malloc(snprintf(NULL, 0, "%s %s", first, second) + 1);
sprintf(s, "%s %s", first, second);

If your platform supports GNU extensions, you could also use asprintf():

char * s = NULL;
asprintf(&s, "%s %s", first, second);

If you're stuck with the MS C Runtime, you have to use _scprintf() to determine the length of the resulting string:

char * s = malloc(_scprintf("%s %s", first, second) + 1);
sprintf(s, "%s %s", first, second);

The following will most likely be the fastest solution:

size_t len1 = strlen(first);
size_t len2 = strlen(second);

char * s = malloc(len1 + len2 + 2);
memcpy(s, first, len1);
s[len1] = ' ';
memcpy(s + len1 + 1, second, len2 + 1); // includes terminating null

Deserialize JSON with Jackson into Polymorphic Types - A Complete Example is giving me a compile error

A simple way to enable polymorphic serialization / deserialization via Jackson library is to globally configure the Jackson object mapper (jackson.databind.ObjectMapper) to add information, such as the concrete class type, for certain kinds of classes, such as abstract classes.

To do that, just make sure your mapper is configured correctly. For example:

Option 1: Support polymorphic serialization / deserialization for abstract classes (and Object typed classes)

jacksonObjectMapper.enableDefaultTyping(
    ObjectMapper.DefaultTyping.OBJECT_AND_NON_CONCRETE); 

Option 2: Support polymorphic serialization / deserialization for abstract classes (and Object typed classes), and arrays of those types.

jacksonObjectMapper.enableDefaultTyping(
    ObjectMapper.DefaultTyping.NON_CONCRETE_AND_ARRAYS); 

Reference: https://github.com/FasterXML/jackson-docs/wiki/JacksonPolymorphicDeserialization

User GETDATE() to put current date into SQL variable

You can also use CURRENT_TIMESTAMP for this.

According to BOL CURRENT_TIMESTAMP is the ANSI SQL euivalent to GETDATE()

DECLARE @LastChangeDate AS DATE;
SET @LastChangeDate = CURRENT_TIMESTAMP;

Variable used in lambda expression should be final or effectively final

if it is not necessary to modify the variable than a general workaround for this kind of problem would be to extract the part of code which use lambda and use final keyword on method-parameter.

Unable to find velocity template resources

I faced a similar issue. I was copying the velocity engine mail templates in wrong folder. Since JavaMailSender and VelocityEngine are declared as resources under MailService, its required to add the templates under resource folder declared for the project.

I made the changes and it worked. Put the templates as

src/main/resources/templates/<package>/sampleMail.vm

How do you tell if a checkbox is selected in Selenium for Java?

I would do it with cssSelector:

// for all checked checkboxes
driver.findElements(By.cssSelector("input:checked[type='checkbox']"));
// for all notchecked checkboxes
driver.findElements(By.cssSelector("input:not(:checked)[type='checkbox']"));

Maybe that also helps ;-)

FFMPEG mp4 from http live streaming m3u8 file?

Aergistal's answer works, but I found that converting to mp4 can make some m3u8 videos broken. If you are stuck with this problem, try to convert them to mkv, and convert them to mp4 later.

NotificationCenter issue on Swift 3

Swift 3 & 4

Swift 3, and now Swift 4, have replaced many "stringly-typed" APIs with struct "wrapper types", as is the case with NotificationCenter. Notifications are now identified by a struct Notfication.Name rather than by String. For more details see the now legacy Migrating to Swift 3 guide

Swift 2.2 usage:

// Define identifier
let notificationIdentifier: String = "NotificationIdentifier"

// Register to receive notification
NSNotificationCenter.defaultCenter().addObserver(self, selector: #selector(YourClassName.methodOfReceivedNotification(_:)), name: notificationIdentifier, object: nil)

// Post a notification
NSNotificationCenter.defaultCenter().postNotificationName(notificationIdentifier, object: nil)

Swift 3 & 4 usage:

// Define identifier
let notificationName = Notification.Name("NotificationIdentifier")

// Register to receive notification
NotificationCenter.default.addObserver(self, selector: #selector(YourClassName.methodOfReceivedNotification), name: notificationName, object: nil)

// Post notification
NotificationCenter.default.post(name: notificationName, object: nil)

// Stop listening notification
NotificationCenter.default.removeObserver(self, name: notificationName, object: nil)

All of the system notification types are now defined as static constants on Notification.Name; i.e. .UIApplicationDidFinishLaunching, .UITextFieldTextDidChange, etc.

You can extend Notification.Name with your own custom notifications in order to stay consistent with the system notifications:

// Definition:
extension Notification.Name {
    static let yourCustomNotificationName = Notification.Name("yourCustomNotificationName")
}

// Usage:
NotificationCenter.default.post(name: .yourCustomNotificationName, object: nil)

Swift 4.2 usage:

Same as Swift 4, except now system notifications names are part of UIApplication. So in order to stay consistent with the system notifications you can extend UIApplication with your own custom notifications instead of Notification.Name :

// Definition:
UIApplication {
    public static let yourCustomNotificationName = Notification.Name("yourCustomNotificationName")
}

// Usage:
NotificationCenter.default.post(name: UIApplication.yourCustomNotificationName, object: nil)

Easy interview question got harder: given numbers 1..100, find the missing number(s) given exactly k are missing

Can you check if every number exists? If yes you may try this:

S = sum of all numbers in the bag (S < 5050)
Z = sum of the missing numbers 5050 - S

if the missing numbers are x and y then:

x = Z - y and
max(x) = Z - 1

So you check the range from 1 to max(x) and find the number

How to get a substring between two strings in PHP?

In PHP's strpos style this will return false if the start mark sm or the end mark em are not found.

This result (false) is different from an empty string that is what you get if there is nothing between the start and end marks.

function between( $str, $sm, $em )
{
    $s = strpos( $str, $sm );
    if( $s === false ) return false;
    $s += strlen( $sm );
    $e = strpos( $str, $em, $s );
    if( $e === false ) return false;
    return substr( $str, $s, $e - $s );
}

The function will return only the first match.

It's obvious but worth mentioning that the function will first look for sm and then for em.

This implies you may not get the desired result/behaviour if em has to be searched first and then the string have to be parsed backward in search of sm.

R adding days to a date

In addition to the simple addition shown by others, you can also use seq.Date or seq.POSIXt to find other increments or decrements (the POSIXt version does seconds, minutes, hours, etc.):

> seq.Date( Sys.Date(), length=2, by='3 months' )[2]
[1] "2012-07-25"

Oracle SQL - select within a select (on the same table!)

I'm a bit confused by the quotes, however, below should work for you:

SELECT "Gc_Staff_Number",
       "Start_Date", x.end_date
FROM   "Employment_History" eh,
(SELECT "End_Date"
        FROM   "Employment_History"
        WHERE  "Current_Flag" != 'Y'
               AND ROWNUM = 1
               AND "Employee_Number" = eh.Employee_Number
        ORDER  BY "End_Date" ASC) x
WHERE  "Current_Flag" = 'Y'

python numpy/scipy curve fitting

You'll first need to separate your numpy array into two separate arrays containing x and y values.

x = [1, 2, 3, 9]
y = [1, 4, 1, 3]

curve_fit also requires a function that provides the type of fit you would like. For instance, a linear fit would use a function like

def func(x, a, b):
    return a*x + b

scipy.optimize.curve_fit(func, x, y) will return a numpy array containing two arrays: the first will contain values for a and b that best fit your data, and the second will be the covariance of the optimal fit parameters.

Here's an example for a linear fit with the data you provided.

import numpy as np
from scipy.optimize import curve_fit

x = np.array([1, 2, 3, 9])
y = np.array([1, 4, 1, 3])

def fit_func(x, a, b):
    return a*x + b

params = curve_fit(fit_func, x, y)

[a, b] = params[0]

This code will return a = 0.135483870968 and b = 1.74193548387

Here's a plot with your points and the linear fit... which is clearly a bad one, but you can change the fitting function to obtain whatever type of fit you would like.

enter image description here

Make first letter of a string upper case (with maximum performance)

Easiest way to Capitalize firs letter is:

1- Using Sytem.Globalization;

  // Creates a TextInfo based on the "en-US" culture.
  TextInfo myTI = new CultureInfo("en-US",false).

  myTI.ToTitleCase(textboxname.Text)

`

Store mysql query output into a shell variable

To read the data line-by-line into a Bash array you can do this:

while read -a row
do
    echo "..${row[0]}..${row[1]}..${row[2]}.."
done < <(echo "SELECT A, B, C FROM table_a" | mysql database -u $user -p $password)

Or into individual variables:

while read a b c
do
    echo "..${a}..${b}..${c}.."
done < <(echo "SELECT A, B, C FROM table_a" | mysql database -u $user -p $password)

javascript /jQuery - For Loop

Use a regular for loop and format the index to be used in the selector.

var array = [];
for (var i = 0; i < 4; i++) {
    var selector = '' + i;
    if (selector.length == 1)
        selector = '0' + selector;
    selector = '#event' + selector;
    array.push($(selector, response).html());
}

Angular ForEach in Angular4/Typescript?

in angular4 foreach like that. try this.

 selectChildren(data, $event) {
      let parentChecked = data.checked;
       this.hierarchicalData.forEach(obj => {
          obj.forEach(childObj=> {
            value.checked = parentChecked;
         });
      });
    }

Plot a bar using matplotlib using a dictionary

It's a little simpler than most answers here suggest:

import matplotlib.pyplot as plt

D = {u'Label1':26, u'Label2': 17, u'Label3':30}
plt.bar(*zip(*D.items()))
plt.show()

enter image description here

What is ModelState.IsValid valid for in ASP.NET MVC in NerdDinner?

Yes , Jared and Kelly Orr are right. I use the following code like in edit exception.

foreach (var issue in dinner.GetRuleViolations())
{
    ModelState.AddModelError(issue.PropertyName, issue.ErrorMessage);
}

in stead of

ModelState.AddRuleViolations(dinner.GetRuleViolations());

How can I get the root domain URI in ASP.NET?

string hostUrl = Request.Url.Scheme + "://" + Request.Url.Host; //should be "http://hostnamehere.com"

Error TF30063: You are not authorized to access ... \DefaultCollection

Try making Internet Explorer your default browser temporarily.

Spring schemaLocation fails when there is no internet connection

You need to add schema locations to your bean definition, and then they can be found in classpath instead of fetched over the net. Given your formatting problems, I'm not 100% sure that you aren't doing this already.

<?xml version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:context="http://www.springframework.org/schema/context"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans-2.0.xsd
    http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context-2.5.xsd">
<!-- empty: the beans we use are in the base class's context. -->
</beans>

WAMP server, localhost is not working

The best solution is:

  1. Right click on Computer -> Properties -> Device manager.
  2. View -> Show hidden devices.
  3. Choose Non-plug and plug drivers -> HTTP -> Disable.
  4. Restart your computer.

If statements for Checkboxes

Your going to use the checkbox1.checked property in your if statement, this returns true or false depending on weather it is checked or not.

Reading NFC Tags with iPhone 6 / iOS 8

The ability to read an NFC tag has been added to iOS 11 which only support iPhone 7 and 7 plus

As a test drive I made this repo

First: We need to initiate NFCNDEFReaderSession class

var session: NFCNDEFReaderSession? 
session = NFCNDEFReaderSession(delegate: self, queue: nil, invalidateAfterFirstRead: false)

Then we need to start the session by:

session?.begin()

and when done:

session?.invalidate()

The delegate (which self should implement) has basically two functions:

func readerSession(_ session: NFCNDEFReaderSession, didDetectNDEFs messages: [NFCNDEFMessage])
func readerSession(_ session: NFCNDEFReaderSession, didInvalidateWithError error: Error)

here is my reference Apple docs

How to convert string date to Timestamp in java?

tl;dr

java.sql.Timestamp                  
.valueOf(                           // Class-method parses SQL-style formatted date-time strings.
    "2007-11-11 12:13:14"
)                                   // Returns a `Timestamp` object.
.toInstant()                        // Converts from terrible legacy classes to modern *java.time* class.

java.sql.Timestamp.valueOf parses SQL format

If you can use the full four digits for the year, your input string of 2007-11-11 12:13:14 would be in standard SQL format assuming this value is meant to be in UTC time zone.

The java.sql.Timestamp class has a valueOf method to directly parse such strings.

String input = "2007-11-11 12:13:14" ;
java.sql.Timestamp ts = java.sql.Timestamp.valueOf( input ) ;

java.time

In Java 8 and later, the java.time framework makes it easier to verify the results. The j.s.Timestamp class has a nasty habit of implicitly applying your JVM’s current default timestamp when generating a string representation via its toString method. In contrast, the java.time classes by default use the standard ISO 8601 formats.

System.out.println( "Output: " + ts.toInstant().toString() );

What is the difference between require() and library()?

My initial theory about the difference was that library loads the packages whether it is already loaded or not, i.e. it might reload an already loaded package, while require just checks that it is loaded, or loads it if it isn't (thus the use in functions that rely on a certain package). The documentation refutes this, however, and explicitly states that neither function will reload an already loaded package.

Exception Error c0000005 in VC++

Exception code c0000005 is the code for an access violation. That means that your program is accessing (either reading or writing) a memory address to which it does not have rights. Most commonly this is caused by:

  • Accessing a stale pointer. That is accessing memory that has already been deallocated. Note that such stale pointer accesses do not always result in access violations. Only if the memory manager has returned the memory to the system do you get an access violation.
  • Reading off the end of an array. This is when you have an array of length N and you access elements with index >=N.

To solve the problem you'll need to do some debugging. If you are not in a position to get the fault to occur under your debugger on your development machine you should get a crash dump file and load it into your debugger. This will allow you to see where in the code the problem occurred and hopefully lead you to the solution. You'll need to have the debugging symbols associated with the executable in order to see meaningful stack traces.

Add text to Existing PDF using Python

I know this is an older post, but I spent a long time trying to find a solution. I came across a decent one using only ReportLab and PyPDF so I thought I'd share:

  1. read your PDF using PdfFileReader(), we'll call this input
  2. create a new pdf containing your text to add using ReportLab, save this as a string object
  3. read the string object using PdfFileReader(), we'll call this text
  4. create a new PDF object using PdfFileWriter(), we'll call this output
  5. iterate through input and apply .mergePage(*text*.getPage(0)) for each page you want the text added to, then use output.addPage() to add the modified pages to a new document

This works well for simple text additions. See PyPDF's sample for watermarking a document.

Here is some code to answer the question below:

packet = StringIO.StringIO()
can = canvas.Canvas(packet, pagesize=letter)
<do something with canvas>
can.save()
packet.seek(0)
input = PdfFileReader(packet)

From here you can merge the pages of the input file with another document.

git checkout all the files

If you are at the root of your working directory, you can do git checkout -- . to check-out all files in the current HEAD and replace your local files.

You can also do git reset --hard to reset your working directory and replace all changes (including the index).

How to len(generator())

You can len(list(generator)) but you could probably make something more efficient if you really intend to discard the results.

How to block users from closing a window in Javascript?

It's poor practice to force the user to do something they don't necessarily want to do. You can't ever really prevent them from closing the browser.

You can achieve a similar effect, though, by making a div on your current web page to layer over top the rest of your controls so your form is the only thing accessible.

react-native :app:installDebug FAILED

If none of the above solutions works then try the following steps to cold boot the emulator

open AVD manager -> Edit device -> Show Advanced Settings -> Boot option -> select Cold Boot instead of Quick boot.

Jquery check if element is visible in viewport

According to the documentation for that plugin, .visible() returns a boolean indicating if the element is visible. So you'd use it like this:

if ($('#element').visible(true)) {
    // The element is visible, do something
} else {
    // The element is NOT visible, do something else
}

How to check in Javascript if one element is contained within another

Take a look at Node#compareDocumentPosition.

function isDescendant(ancestor,descendant){
    return ancestor.compareDocumentPosition(descendant) & 
        Node.DOCUMENT_POSITION_CONTAINS;
}

function isAncestor(descendant,ancestor){
    return descendant.compareDocumentPosition(ancestor) & 
        Node.DOCUMENT_POSITION_CONTAINED_BY;
}

Other relationships include DOCUMENT_POSITION_DISCONNECTED, DOCUMENT_POSITION_PRECEDING, and DOCUMENT_POSITION_FOLLOWING.

Not supported in IE<=8.

How to define the css :hover state in a jQuery selector?

Well, you can't add styling using pseudo selectors like :hover, :after, :nth-child, or anything like that using jQuery.

If you want to add a CSS rule like that you have to create a <style> element and add that :hover rule to it just like you would in CSS. Then you would have to add that <style> element to the page.

Using the .hover function seems to be more appropriate if you can't just add the css to a stylesheet, but if you insist you can do:

$('head').append('<style>.myclass:hover div {background-color : red;}</style>')

If you want to read more on adding CSS with javascript you can check out one of David Walsh's Blog posts.

Rails 4 LIKE query - ActiveRecord adds quotes

.find(:all, where: "value LIKE product_%", params: { limit: 20, page: 1 })

how do you filter pandas dataframes by multiple columns

In case somebody wonders what is the faster way to filter (the accepted answer or the one from @redreamality):

import pandas as pd
import numpy as np

length = 100_000
df = pd.DataFrame()
df['Year'] = np.random.randint(1950, 2019, size=length)
df['Gender'] = np.random.choice(['Male', 'Female'], length)

%timeit df.query('Gender=="Male" & Year=="2014" ')
%timeit df[(df['Gender']=='Male') & (df['Year']==2014)]

Results for 100,000 rows:

6.67 ms ± 557 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)
5.54 ms ± 536 µs per loop (mean ± std. dev. of 7 runs, 100 loops each)

Results for 10,000,000 rows:

326 ms ± 6.52 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)
472 ms ± 25.1 ms per loop (mean ± std. dev. of 7 runs, 1 loop each)

So results depend on the size and the data. On my laptop, query() gets faster after 500k rows. Further, the string search in Year=="2014" has an unnecessary overhead (Year==2014 is faster).

How to access form methods and controls from a class in C#?

  1. you have to have a reference to the form object in order to access its elements
  2. the elements have to be declared public in order for another class to access them
  3. don't do this - your class has to know too much about how your form is implemented; do not expose form controls outside of the form class
  4. instead, make public properties on your form to get/set the values you are interested in
  5. post more details of what you want and why, it sounds like you may be heading off in a direction that is not consistent with good encapsulation practices

How to use a variable in the replacement side of the Perl substitution operator?

I would suggest something like:

$text =~ m{(.*)$find(.*)};
$text = $1 . $replace . $2;

It is quite readable and seems to be safe. If multiple replace is needed, it is easy:

while ($text =~ m{(.*)$find(.*)}){
     $text = $1 . $replace . $2;
}

How to create nested directories using Mkdir in Golang?

This is one alternative for achieving the same but it avoids race condition caused by having two distinct "check ..and.. create" operations.

package main

import (
    "fmt"
    "os"
)

func main()  {
    if err := ensureDir("/test-dir"); err != nil {
        fmt.Println("Directory creation failed with error: " + err.Error())
        os.Exit(1)
    }
    // Proceed forward
}

func ensureDir(dirName string) error {

    err := os.MkdirAll(dirName, os.ModeDir)

    if err == nil || os.IsExist(err) {
        return nil
    } else {
        return err
    }
}

How to create a private class method?

By default all class methods are public. To make them private you can use Module#private_class_method like @tjwallace wrote or define them differently, as you did:

class << self

  private

  def method_name
    ...
  end
end

class << self opens up self's singleton class, so that methods can be redefined for the current self object. This is used to define class/module ("static") method. Only there, defining private methods really gives you private class methods.

How to use the TextWatcher class in Android?

if you implement with dialog edittext. use like this:. its same with use to other edittext.

dialog.getInputEditText().addTextChangedListener(new TextWatcher() {
    @Override
    public void beforeTextChanged(CharSequence charSequence, int start, int before, int count) {
    }

    @Override
    public void onTextChanged(CharSequence charSequence, int start, int before, int count) {
        if (start<2){
                dialog.getActionButton(DialogAction.POSITIVE).setEnabled(false);
            }else{
                double size =  Double.parseDouble(charSequence.toString());
                if (size > 0.000001 && size < 0.999999){
                    dialog.getActionButton(DialogAction.POSITIVE).setEnabled(true);
                }else{
                    ToastHelper.show(HistoryActivity.this, "Size must between 0.1 - 0.9");
                    dialog.getActionButton(DialogAction.POSITIVE).setEnabled(false);
                }

            }
    }

    @Override
    public void afterTextChanged(Editable editable) {

    }
});

How to bring an activity to foreground (top of stack)?

The best way I found to do this was to use the same intent as the Android home screen uses - the app Launcher.

For example:

Intent i = new Intent(this, MyMainActivity.class);
i.setAction(Intent.ACTION_MAIN);
i.addCategory(Intent.CATEGORY_LAUNCHER);
startActivity(i);

This way, whatever activity in my package was most recently used by the user is brought back to the front again. I found this useful in using my service's PendingIntent to get the user back to my app.

Update a local branch with the changes from a tracked remote branch

You have set the upstream of that branch

(see:

git branch -f --track my_local_branch origin/my_remote_branch
# OR (if my_local_branch is currently checked out):
$ git branch --set-upstream-to my_local_branch origin/my_remote_branch

(git branch -f --track won't work if the branch is checked out: use the second command git branch --set-upstream-to instead, or you would get "fatal: Cannot force update the current branch.")

That means your branch is already configured with:

branch.my_local_branch.remote origin
branch.my_local_branch.merge my_remote_branch

Git already has all the necessary information.
In that case:

# if you weren't already on my_local_branch branch:
git checkout my_local_branch 
# then:
git pull

is enough.


If you hadn't establish that upstream branch relationship when it came to push your 'my_local_branch', then a simple git push -u origin my_local_branch:my_remote_branch would have been enough to push and set the upstream branch.
After that, for the subsequent pulls/pushes, git pull or git push would, again, have been enough.

C# cannot convert method to non delegate type

You need to add parentheses after a method call, else the compiler will think you're talking about the method itself (a delegate type), whereas you're actually talking about the return value of that method.

string t = obj.getTitle();

Extra Non-Essential Information

Also, have a look at properties. That way you could use title as if it were a variable, while, internally, it works like a function. That way you don't have to write the functions getTitle() and setTitle(string value), but you could do it like this:

public string Title // Note: public fields, methods and properties use PascalCasing
{
    get // This replaces your getTitle method
    {
        return _title; // Where _title is a field somewhere
    }
    set // And this replaces your setTitle method
    {
        _title = value; // value behaves like a method parameter
    }
}

Or you could use auto-implemented properties, which would use this by default:

public string Title { get; set; }

And you wouldn't have to create your own backing field (_title), the compiler would create it itself.

Also, you can change access levels for property accessors (getters and setters):

public string Title { get; private set; }

You use properties as if they were fields, i.e.:

this.Title = "Example";
string local = this.Title;

GET parameters in the URL with CodeIgniter

GET parameters are cached by the web browser, POST is not. So with a POST you don't have to worry about caching, so that is why it is usually prefered.

Git: "Corrupt loose object"

My computer crashed while I was writing a commit message. After rebooting, the working tree was as I had left it and I was able to successfully commit my changes.

However, when I tried to run git status I got

error: object file .git/objects/xx/12345 is empty
fatal: loose object xx12345 (stored in .git/objects/xx/12345 is corrupt

Unlike most of the other answers, I wasn't trying to recover any data. I just needed Git to stop complaining about the empty object file.

Overview

The "object file" is git's hashed representation of a real file that you care about. Git thinks it should have a hashed version of some/file.whatever stored in .git/object/xx/12345, and fixing the error turned out to be mostly a matter of figuring out which file the "loose object" was supposed to represent.

Details

Possible options seemed to be

  1. Delete the empty file
  2. Get the file into a state acceptable to Git

Approach 1: Remove the object file

The first thing I tried was just moving the object file

mv .git/objects/xx/12345 ..

That didn't work - git began complaining about a broken link. On to Approach 2.

Approach 2: Fix the file

Linus Torvalds has a great writeup of how to recover an object file that solved the problem for me. Key steps are summarized here.

$> # Find out which file the blob object refers to
$> git fsck
broken link from    tree 2d9263c6d23595e7cb2a21e5ebbb53655278dff8
           to    blob xx12345
missing blob xx12345

$> git ls-tree 2d926
...
10064 blob xx12345  your_file.whatever

This tells you what file the empty object is supposed to be a hash of. Now you can repair it.

$> git hash-object -w path/to/your_file.whatever

After doing this I checked .git/objects/xx/12345, it was no longer empty, and git stopped complaining.

Input widths on Bootstrap 3

ASP.net MVC go to Content- Site.css and remove or comment this line:

input,
select,
textarea {
    /*max-width: 280px;*/
}

JSON.stringify doesn't work with normal Javascript array

Nice explanation and example above. I found this (JSON.stringify() array bizarreness with Prototype.js) to complete the answer. Some sites implements its own toJSON with JSONFilters, so delete it.

if(window.Prototype) {
    delete Object.prototype.toJSON;
    delete Array.prototype.toJSON;
    delete Hash.prototype.toJSON;
    delete String.prototype.toJSON;
}

it works fine and the output of the test:

console.log(json);

Result:

"{"a":"test","b":["item","item2","item3"]}"

How to create exe of a console application

an EXE file is created as long as you build the project. you can usually find this on the debug folder of you project.

C:\Users\username\Documents\Visual Studio 2012\Projects\ProjectName\bin\Debug

Can regular expressions be used to match nested patterns?

Yes, if it is .NET RegEx-engine. .Net engine supports finite state machine supplied with an external stack. see details

DisplayName attribute from Resources?

public class Person
{
    // Before C# 6.0
    [Display(Name = "Age", ResourceType = typeof(Testi18n.Resource))]
    public string Age { get; set; }

    // After C# 6.0
    // [Display(Name = nameof(Resource.Age), ResourceType = typeof(Resource))]
}
  1. Define ResourceType of the attribute so it looks for a resource
  2. Define Name of the attribute which is used for the key of resource, after C# 6.0, you can use nameof for strong typed support instead of hard coding the key.

  3. Set the culture of current thread in the controller.

Resource.Culture = CultureInfo.GetCultureInfo("zh-CN");

  1. Set the accessibility of the resource to public

  2. Display the label in cshtml like this

@Html.DisplayNameFor(model => model.Age)

Cell Style Alignment on a range

This works good

worksheet.get_Range("A1","A14").Cells.HorizontalAlignment = 
                 Microsoft.Office.Interop.Excel.XlHAlign.xlHAlignLeft;

"Object doesn't support property or method 'find'" in IE

Here is a work around. You can use filter instead of find; but filter returns an array of matching objects. find only returns the first match inside an array. So, why not use filter as following;

data.filter(function (x) {
         return x.Id === e
    })[0];

Access key value from Web.config in Razor View-MVC3 ASP.NET

@System.Configuration.ConfigurationManager.AppSettings["myKey"]

Changing the URL in react-router v4 without using Redirect or Link

Try this,

this.props.router.push('/foo')

warning works for versions prior to v4

and

this.props.history.push('/foo')

for v4 and above

How can I round down a number in Javascript?

Rounding a number towards 0 can be done by subtracting its signed fractional part number % 1:

rounded = number - number % 1;

Like Math.floor (rounds towards -Infinity) this method is perfectly accurate.

There are differences in the handling of -0, +Infinity and -Infinity though:

Math.floor(-0) => -0
-0 - -0 % 1    => +0

Math.floor(Infinity)    => Infinity
Infinity - Infinity % 1 => NaN

Math.floor(-Infinity)     => -Infinity
-Infinity - -Infinity % 1 => NaN

How to disable a link using only CSS?

Thanks to everyone that posted solutions, I combined multiple approaches to provide some more advanced disabled functionality. Here is a gist, and the code is below.

This provides for multiple levels of defense so that Anchors marked as disable actually behave as such.
Using this approach, you get an anchor that you cannot:
  - click
  - tab to and hit return
  - tabbing to it will move focus to the next focusable element
  - it is aware if the anchor is subsequently enabled


1.  Include this css, as it is the first line of defense.  This assumes the selector you use is 'a.disabled'
    a.disabled {
      pointer-events: none;
      cursor: default;
    }

 2. Next, instantiate this class such as (with optional selector):
    $ ->
      new AnchorDisabler()

Here is the coffescript class:

class AnchorDisabler
  constructor: (selector = 'a.disabled') ->
    $(selector).click(@onClick).keyup(@onKeyup).focus(@onFocus)

  isStillDisabled: (ev) =>
    ### since disabled can be a class or an attribute, and it can be dynamically removed, always recheck on a watched event ###
    target = $(ev.target)
    return true if target.hasClass('disabled')
    return true if target.attr('disabled') is 'disabled'
    return false

  onFocus: (ev) =>
    ### if an attempt is made to focus on a disabled element, just move it along to the next focusable one. ###
    return unless @isStillDisabled(ev)

    focusables = $(':focusable')
    return unless focusables

    current = focusables.index(ev.target)
    next = (if focusables.eq(current + 1).length then focusables.eq(current + 1) else focusables.eq(0))

    next.focus() if next


  onClick: (ev) =>
    # disabled could be dynamically removed
    return unless @isStillDisabled(ev)

    ev.preventDefault()
    return false

  onKeyup: (ev) =>

    # 13 is the js key code for Enter, we are only interested in disabling that so get out fast
    code = ev.keyCode or ev.which
    return unless code is 13

    # disabled could be dynamically removed
    return unless @isStillDisabled(ev)

    ev.preventDefault()
    return false

AngularJS app.run() documentation?

Here's the calling order:

  1. app.config()
  2. app.run()
  3. directive's compile functions (if they are found in the dom)
  4. app.controller()
  5. directive's link functions (again, if found)

Here's a simple demo where you can watch each one executing (and experiment if you'd like).

From Angular's module docs:

Run blocks - get executed after the injector is created and are used to kickstart the application. Only instances and constants can be injected into run blocks. This is to prevent further system configuration during application run time.

Run blocks are the closest thing in Angular to the main method. A run block is the code which needs to run to kickstart the application. It is executed after all of the services have been configured and the injector has been created. Run blocks typically contain code which is hard to unit-test, and for this reason should be declared in isolated modules, so that they can be ignored in the unit-tests.

One situation where run blocks are used is during authentications.

Python script header

Yes, there is - python may not be in /usr/bin, but for example in /usr/local/bin (BSD).

When using virtualenv, it may even be something like ~/projects/env/bin/python

SHA-1 fingerprint of keystore certificate

First there is same .jar file that in fb-sdk android-support-v4.jar.
Then generate SHA1 key using:

PackageInfo info;
try {

    info = getPackageManager().getPackageInfo(
        "com.example.worldmission", PackageManager.GET_SIGNATURES);

    for (Signature signature : info.signatures) {
        MessageDigest md;
        md = MessageDigest.getInstance("SHA");
        md.update(signature.toByteArray());
        String something = new String(Base64.encode(md.digest(), 0));
        Log.e("Hash key", something);
        System.out.println("Hash key" + something);
    }

} catch (NameNotFoundException e1) {
    Log.e("name not found", e1.toString());
} catch (NoSuchAlgorithmException e) {
    Log.e("no such an algorithm", e.toString());
} catch (Exception e) {
    Log.e("exception", e.toString());
}

How to Configure SSL for Amazon S3 bucket

Custom domain SSL certs were just added today for $600/cert/month. Sign up for your invite below: http://aws.amazon.com/cloudfront/custom-ssl-domains/

Update: SNI customer provided certs are now available for no additional charge. Much cheaper than $600/mo, and with XP nearly killed off, it should work well for most use cases.

@skalee AWS has a mechanism for achieving what the poster asks for, "implement SSL for an Amazon s3 bucket", it's called CloudFront. I'm reading "implement" as "use my SSL certs," not "just put an S on the HTTP URL which I'm sure the OP could have surmised.

Since CloudFront costs exactly the same as S3 ($0.12/GB), but has a ton of additional features around SSL AND allows you to add your own SNI cert at no additional cost, it's the obvious fix for "implementing SSL" on your domain.

Shorten string without cutting words in JavaScript

I'm late to the party, but here's a small and easy solution I came up with to return an amount of words.

It's not directly related to your requirement of characters, but it serves the same outcome that I believe you were after.

function truncateWords(sentence, amount, tail) {
  const words = sentence.split(' ');

  if (amount >= words.length) {
    return sentence;
  }

  const truncated = words.slice(0, amount);
  return `${truncated.join(' ')}${tail}`;
}

const sentence = 'Sed ut perspiciatis unde omnis iste natus error sit voluptatem accusantium doloremque laudantium, totam rem aperiam, eaque ipsa quae ab illo inventore veritatis et quasi architecto beatae vitae dicta sunt explicabo.';

console.log(truncateWords(sentence, 10, '...'));

See the working example here: https://jsfiddle.net/bx7rojgL/

Add st, nd, rd and th (ordinal) suffix to a number

Old one I made for my stuff...

function convertToOrdinal(number){
    if (number !=1){
        var numberastext = number.ToString();
        var endchar = numberastext.Substring(numberastext.Length - 1);
        if (number>9){
            var secondfromendchar = numberastext.Substring(numberastext.Length - 1);
            secondfromendchar = numberastext.Remove(numberastext.Length - 1);
        }
        var suffix = "th";
        var digit = int.Parse(endchar);
        switch (digit){
            case 3:
                if(secondfromendchar != "1"){
                    suffix = "rd";
                    break;
                }
            case 2:
                if(secondfromendchar != "1"){
                    suffix = "nd";
                    break;
                }
            case 1:
                if(secondfromendchar != "1"){
                    suffix = "st";
                    break;
                }
            default:
                suffix = "th";
                break;
         }
            return number+suffix+" ";
     } else {
            return;
     }
}

The type or namespace name 'Entity' does not exist in the namespace 'System.Data'

tried reinstall - no luck. i had to refresh a table in my model before it would find Entity.

jQuery show/hide not working

Use this

<script>
$(document).ready(function(){
    $( '.expand' ).click(function() {
        $( '.img_display_content' ).show();
    });
});
</script>

Event assigning always after Document Object Model loaded

Combine Regexp?

Will the conditions be ORed or ANDed together?

Starts with: abc
Ends with: xyz
Contains: 123
Doesn't contain: 456

The OR version is fairly simple; as you said, it's mostly a matter of inserting pipes between individual conditions. The regex simply stops looking for a match as soon as one of the alternatives matches.

/^abc|xyz$|123|^(?:(?!456).)*$/

That fourth alternative may look bizarre, but that's how you express "doesn't contain" in a regex. By the way, the order of the alternatives doesn't matter; this is effectively the same regex:

/xyz$|^(?:(?!456).)*$|123|^abc/

The AND version is more complicated. After each individual regex matches, the match position has to be reset to zero so the next regex has access to the whole input. That means all of the conditions have to be expressed as lookaheads (technically, one of them doesn't have to be a lookahead, I think it expresses the intent more clearly this way). A final .*$ consummates the match.

/^(?=^abc)(?=.*xyz$)(?=.*123)(?=^(?:(?!456).)*$).*$/

And then there's the possibility of combined AND and OR conditions--that's where the real fun starts. :D

Map a 2D array onto a 1D array

You need to decide whether the array elements will be stored in row order or column order and then be consistent about it. http://en.wikipedia.org/wiki/Row-major_order

The C language uses row order for Multidimensional arrays

To simulate this with a single dimensional array, you multiply the row index by the width, and add the column index thus:

 int array[width * height];

 int SetElement(int row, int col, int value)
 {
    array[width * row + col] = value;  
 }

SimpleDateFormat parse loses timezone

tl;dr

what is the way to retrieve a Date object so that its always in GMT?

Instant.now() 

Details

You are using troublesome confusing old date-time classes that are now supplanted by the java.time classes.

Instant = UTC

The Instant class represents a moment on the timeline in UTC with a resolution of nanoseconds (up to nine (9) digits of a decimal fraction).

Instant instant = Instant.now() ; // Current moment in UTC.

ISO 8601

To exchange this data as text, use the standard ISO 8601 formats exclusively. These formats are sensibly designed to be unambiguous, easy to process by machine, and easy to read across many cultures by people.

The java.time classes use the standard formats by default when parsing and generating strings.

String output = instant.toString() ;  

2017-01-23T12:34:56.123456789Z

Time zone

If you want to see that same moment as presented in the wall-clock time of a particular region, apply a ZoneId to get a ZonedDateTime.

Specify a proper time zone name in the format of continent/region, such as America/Montreal, Africa/Casablanca, or Pacific/Auckland. Never use the 3-4 letter abbreviation such as EST or IST as they are not true time zones, not standardized, and not even unique(!).

ZoneId z = ZoneId.of( "Asia/Singapore" ) ;
ZonedDateTime zdt = instant.atZone( z ) ;  // Same simultaneous moment, same point on the timeline.

See this code live at IdeOne.com.

Notice the eight hour difference, as the time zone of Asia/Singapore currently has an offset-from-UTC of +08:00. Same moment, different wall-clock time.

instant.toString(): 2017-01-23T12:34:56.123456789Z

zdt.toString(): 2017-01-23T20:34:56.123456789+08:00[Asia/Singapore]

Convert

Avoid the legacy java.util.Date class. But if you must, you can convert. Look to new methods added to the old classes.

java.util.Date date = Date.from( instant ) ;

…going the other way…

Instant instant = myJavaUtilDate.toInstant() ;

Date-only

For date-only, use LocalDate.

LocalDate ld = zdt.toLocalDate() ;

About java.time

The java.time framework is built into Java 8 and later. These classes supplant the troublesome old legacy date-time classes such as java.util.Date, Calendar, & SimpleDateFormat.

The Joda-Time project, now in maintenance mode, advises migration to the java.time classes.

To learn more, see the Oracle Tutorial. And search Stack Overflow for many examples and explanations. Specification is JSR 310.

Where to obtain the java.time classes?

The ThreeTen-Extra project extends java.time with additional classes. This project is a proving ground for possible future additions to java.time. You may find some useful classes here such as Interval, YearWeek, YearQuarter, and more.

How do I remove a specific element from a JSONArray?

public static JSONArray RemoveJSONArray( JSONArray jarray,int pos) {

JSONArray Njarray=new JSONArray();
try{
for(int i=0;i<jarray.length();i++){     
    if(i!=pos)
        Njarray.put(jarray.get(i));     
}
}catch (Exception e){e.printStackTrace();}
return Njarray;

}

What's the difference between lists enclosed by square brackets and parentheses in Python?

The first is a list, the second is a tuple. Lists are mutable, tuples are not.

Take a look at the Data Structures section of the tutorial, and the Sequence Types section of the documentation.