Programs & Examples On #Ssid

Get SSID when WIFI is connected

I found interesting solution to get SSID of currently connected Wifi AP. You simply need to use iterate WifiManager.getConfiguredNetworks() and find configuration with specific WifiInfo.getNetworkId()

My example

in Broadcast receiver with action WifiManager.NETWORK_STATE_CHANGED_ACTION I'm getting current connection state from intent

NetworkInfo nwInfo = intent.getParcelableExtra(WifiManager.EXTRA_NETWORK_INFO);
nwInfo.getState()

If NetworkInfo.getState is equal to NetworkInfo.State.CONNECTED then i can get current WifiInfo object

WifiManager wifiManager = (WifiManager) getSystemService (Context.WIFI_SERVICE);
WifiInfo info = wifiManager.getConnectionInfo ();

And after that

public String findSSIDForWifiInfo(WifiManager manager, WifiInfo wifiInfo) {

    List<WifiConfiguration> listOfConfigurations = manager.getConfiguredNetworks();

    for (int index = 0; index < listOfConfigurations.size(); index++) {
        WifiConfiguration configuration = listOfConfigurations.get(index);
        if (configuration.networkId == wifiInfo.getNetworkId()) {
            return configuration.SSID;
        }
    }

    return null;
}

And very important thing this method doesn't require Location nor Location Permisions

In API29 Google redesigned Wifi API so this solution is outdated for Android 10.

iPhone get SSID without private library

Here's the cleaned up ARC version, based on @elsurudo's code:

- (id)fetchSSIDInfo {
     NSArray *ifs = (__bridge_transfer NSArray *)CNCopySupportedInterfaces();
     NSLog(@"Supported interfaces: %@", ifs);
     NSDictionary *info;
     for (NSString *ifnam in ifs) {
         info = (__bridge_transfer NSDictionary *)CNCopyCurrentNetworkInfo((__bridge CFStringRef)ifnam);
         NSLog(@"%@ => %@", ifnam, info);
         if (info && [info count]) { break; }
     }
     return info;
}

Live Video Streaming with PHP

I am not saying that you have to abandon PHP, but you need different technologies here.

Let's start off simple (without Akamai :-)) and think about the implications here. Video, chat, etc. - it's all client-side in the beginning. The user has a webcam, you want to grab the signal somehow and send it to the server. There is no PHP so far.

I know that Flash supports this though (check this tutorial on webcams and flash) so you could use Flash to transport the content to the server. I think if you'll stay with Flash, then Flex (flex and webcam tutorial) is probably a good idea to look into.

So those are just the basics, maybe it gives you an idea of where you need to research because obviously this won't give you a full video chat inside your app yet. For starters, you will need some sort of way to record the streams and re-publish them so others see other people from the chat, etc..

I'm also not sure how much traffic and bandwidth this is gonna consume though and generally, you will need way more than a Stackoverflow question to solve this issue. Best would be to do a full spec of your app and then hire some people to help you build it.

HTH!

Add Variables to Tuple

In Python 3, you can use * to create a new tuple of elements from the original tuple along with the new element.

>>> tuple1 = ("foo", "bar")
>>> tuple2 = (*tuple1, "baz")
>>> tuple2
('foo', 'bar', 'baz')

The byte code is almost the same as tuple1 + ("baz",)

Python 3.7.5 (default, Oct 22 2019, 10:35:10) 
[Clang 10.0.1 (clang-1001.0.46.4)] on darwin
Type "help", "copyright", "credits" or "license" for more information.
>>> def f():
...     tuple1 = ("foo", "bar")
...     tuple2 = (*tuple1, "baz")
...     return tuple2
... 
>>> def g():
...     tuple1 = ("foo", "bar")
...     tuple2 = tuple1 + ("baz",)
...     return tuple2
... 
>>> from dis import dis
>>> dis(f)
  2           0 LOAD_CONST               1 (('foo', 'bar'))
              2 STORE_FAST               0 (tuple1)

  3           4 LOAD_FAST                0 (tuple1)
              6 LOAD_CONST               3 (('baz',))
              8 BUILD_TUPLE_UNPACK       2
             10 STORE_FAST               1 (tuple2)

  4          12 LOAD_FAST                1 (tuple2)
             14 RETURN_VALUE
>>> dis(g)
  2           0 LOAD_CONST               1 (('foo', 'bar'))
              2 STORE_FAST               0 (tuple1)

  3           4 LOAD_FAST                0 (tuple1)
              6 LOAD_CONST               2 (('baz',))
              8 BINARY_ADD
             10 STORE_FAST               1 (tuple2)

  4          12 LOAD_FAST                1 (tuple2)
             14 RETURN_VALUE

The only difference is BUILD_TUPLE_UNPACK vs BINARY_ADD. The exact performance depends on the Python interpreter implementation, but it's natural to implement BUILD_TUPLE_UNPACK faster than BINARY_ADD because BINARY_ADD is a polymorphic operator, requiring additional type calculation and implicit conversion.

./xx.py: line 1: import: command not found

I've experienced the same problem and now I just found my solution to this issue.

#!/usr/bin/python

import sys
import os

os.system('meld "%s" "%s"' % (sys.argv[2], sys.argv[5]))

This is the code[1] for my case. When I tried this script I received error message like :

import: command not found

I found people talks about the shebang. As you see there is the shebang in my python code above. I tried these and those trials but didn't find a good solution.

I finally tried to type the shebang my self.

#!/usr/bin/python

and removed the copied one.

And my problem solved!!!

I copied the code from the internet[1].

And I guess there had been some unseeable(?) unseen special characters in the original copied shebang statement.

I use vim, sometimes I experience similar problems.. Especially when I copied some code snippet from the internet this kind of problems happen.. Web pages have some virus special characters!! I doubt. :-)

Journeyer

PS) I copied the code in Windows 7 - host OS - into the Windows clipboard and pasted it into my vim in Ubuntu - guest OS. VM is Oracle Virtual Machine.

[1] http://nathanhoad.net/how-to-meld-for-git-diffs-in-ubuntu-hardy

Change string color with NSAttributedString?

There is no need for using NSAttributedString. All you need is a simple label with the proper textColor. Plus this simple solution will work with all versions of iOS, not just iOS 6.

But if you needlessly wish to use NSAttributedString, you can do something like this:

UIColor *color = [UIColor redColor]; // select needed color
NSString *string = ... // the string to colorize
NSDictionary *attrs = @{ NSForegroundColorAttributeName : color };
NSAttributedString *attrStr = [[NSAttributedString alloc] initWithString:string attributes:attrs];
self.scanLabel.attributedText = attrStr;

How to Set a Custom Font in the ActionBar Title?

I just did the following inside the onCreate() function:

TypefaceSpan typefaceSpan = new TypefaceSpan("font_to_be_used");
SpannableString str = new SpannableString("toolbar_text");
str.setSpan(typefaceSpan,0, str.length(), Spanned.SPAN_EXCLUSIVE_EXCLUSIVE);
getSupportActionBar().setTitle(str);

I am using the Support Libraries, if you are not using them I guess you should switch to getActionBar() instead of getSupportActionBar().

In Android Studio 3 you can add custom fonts following this instructions https://developer.android.com/guide/topics/ui/look-and-feel/fonts-in-xml.html and then use your newly added font in "font_to_be_used"

how to set imageview src?

What you are looking for is probably this:

ImageView myImageView;
myImageView = mDialog.findViewById(R.id.image_id);
String src = "imageFileName"

int drawableId = this.getResources().getIdentifier(src, "drawable", context.getPackageName())
popupImageView.setImageResource(drawableId);

Let me know if this was helpful :)

remove borders around html input

It's simple

input {border:0;outline:0;}
input:focus {outline:none!important;}

C++ Calling a function from another class

Here's my solution to the issue. Tried to keep it straight and simple.

#include <iostream>
using namespace std;

class Game{
public:
  void init(){
    cout << "Hi" << endl;
  }
}g;

class b : Game{  //class b uses/imports class Game
public:
  void h(){
    init(); //Use function from class Game
  }
}A;

int main()
{
  A.h();
  return 0;
}

What is the function __construct used for?

I believe that function __construct () {...} is a piece of code that can be reused again and again in substitution for TheActualFunctionName () {...}. If you change the CLASS Name you do not have to change within the code because the generic __construct refers always to the actual class name...whatever it is. You code less...or?

One line if in VB .NET

if Condition then command1 : else command2...

Can we instantiate an abstract class?

Technical Answer

Abstract classes cannot be instantiated - this is by definition and design.

From the JLS, Chapter 8. Classes:

A named class may be declared abstract (§8.1.1.1) and must be declared abstract if it is incompletely implemented; such a class cannot be instantiated, but can be extended by subclasses.

From JSE 6 java doc for Classes.newInstance():

InstantiationException - if this Class represents an abstract class, an interface, an array class, a primitive type, or void; or if the class has no nullary constructor; or if the instantiation fails for some other reason.

You can, of course, instantiate a concrete subclass of an abstract class (including an anonymous subclass) and also carry out a typecast of an object reference to an abstract type.

A Different Angle On This - Teamplay & Social Intelligence:

This sort of technical misunderstanding happens frequently in the real world when we deal with complex technologies and legalistic specifications.

"People Skills" can be more important here than "Technical Skills". If competitively and aggressively trying to prove your side of the argument, then you could be theoretically right, but you could also do more damage in having a fight / damaging "face" / creating an enemy than it is worth. Be reconciliatory and understanding in resolving your differences. Who knows - maybe you're "both right" but working off slightly different meanings for terms??

Who knows - though not likely, it is possible the interviewer deliberately introduced a small conflict/misunderstanding to put you into a challenging situation and see how you behave emotionally and socially. Be gracious and constructive with colleagues, follow advice from seniors, and follow through after the interview to resolve any challenge/misunderstanding - via email or phone call. Shows you're motivated and detail-oriented.

How to check String in response body with mockMvc

One possible approach is to simply include gson dependency:

<dependency>
    <groupId>com.google.code.gson</groupId>
    <artifactId>gson</artifactId>
</dependency>

and parse the value to make your verifications:

@RunWith(SpringRunner.class)
@WebMvcTest(HelloController.class)
public class HelloControllerTest {

    @Autowired
    private MockMvc mockMvc;

    @MockBean
    private HelloService helloService;

    @Before
    public void before() {
        Mockito.when(helloService.message()).thenReturn("hello world!");
    }

    @Test
    public void testMessage() throws Exception {
        MvcResult mvcResult = mockMvc.perform(MockMvcRequestBuilders.get("/"))
                .andExpect(status().isOk())
                .andExpect(content().contentTypeCompatibleWith(MediaType.APPLICATION_JSON_VALUE))
                .andReturn();

        String responseBody = mvcResult.getResponse().getContentAsString();
        ResponseDto responseDto
                = new Gson().fromJson(responseBody, ResponseDto.class);
        Assertions.assertThat(responseDto.message).isEqualTo("hello world!");
    }
}

Laravel 5 not finding css files

if you are on ubuntu u can try these commands:

sudo apt install npm

npm install && npm run dev

gcc-arm-linux-gnueabi command not found

If you are on a 64bit build of ubuntu or debian (see e.g. 'cat /proc/version') you should simply use the 64bit cross compilers, if you cloned

git clone https://github.com/raspberrypi/tools

then the 64bit tools are in

tools/arm-bcm2708/gcc-linaro-arm-linux-gnueabihf-raspbian-x64

use that directory for the gcc-toolchain. A useful tutorial for compiling that I followed is available here Building and compiling Raspberry PI Kernel (use the -x64 path from above as ${CCPREFIX})

git cherry-pick says "...38c74d is a merge but no -m option was given"

Simplify. Cherry-pick the commits. Don't cherry-pick the merge.

Here's a rewrite of the accepted answer that ideally clarifies the advantages/risks of possible approaches:

You're trying to cherry pick fd9f578, which was a merge with two parents.

Instead of cherry-picking a merge, the simplest thing is to cherry pick the commit(s) you actually want from each branch in the merge.

Since you've already merged, it's likely all your desired commits are in your list. Cherry-pick them directly and you don't need to mess with the merge commit.

explanation

The way a cherry-pick works is by taking the diff that a changeset represents (the difference between the working tree at that point and the working tree of its parent), and applying the changeset to your current branch.

If a commit has two or more parents, as is the case with a merge, that commit also represents two or more diffs. The error occurs because of the uncertainty over which diff should apply.

alternatives

If you determine you need to include the merge vs cherry-picking the related commits, you have two options:

  1. (More complicated and obscure; also discards history) you can indicate which parent should apply.

    • Use the -m option to do so. For example, git cherry-pick -m 1 fd9f578 will use the first parent listed in the merge as the base.

    • Also consider that when you cherry-pick a merge commit, it collapses all the changes made in the parent you didn't specify to -m into that one commit. You lose all their history, and glom together all their diffs. Your call.

  2. (Simpler and more familiar; preserves history) you can use git merge instead of git cherry-pick.

    • As is usual with git merge, it will attempt to apply all commits that exist on the branch you are merging, and list them individually in your git log.

How to use phpexcel to read data and insert into database?

Using the PHPExcel library to read an Excel file and transfer the data into a database

//  Include PHPExcel_IOFactory
include 'PHPExcel/IOFactory.php';

$inputFileName = './sampleData/example1.xls';

//  Read your Excel workbook
try {
    $inputFileType = PHPExcel_IOFactory::identify($inputFileName);
    $objReader = PHPExcel_IOFactory::createReader($inputFileType);
    $objPHPExcel = $objReader->load($inputFileName);
} catch(Exception $e) {
    die('Error loading file "'.pathinfo($inputFileName,PATHINFO_BASENAME).'": '.$e->getMessage());
}

//  Get worksheet dimensions
$sheet = $objPHPExcel->getSheet(0); 
$highestRow = $sheet->getHighestRow(); 
$highestColumn = $sheet->getHighestColumn();

//  Loop through each row of the worksheet in turn
for ($row = 1; $row <= $highestRow; $row++){ 
    //  Read a row of data into an array
    $rowData = $sheet->rangeToArray('A' . $row . ':' . $highestColumn . $row,
                                    NULL,
                                    TRUE,
                                    FALSE);
    //  Insert row data array into your database of choice here
}

Anything more becomes very dependent on your database, and how you want the data structured in it

Can I have multiple :before pseudo-elements for the same element?

In CSS2.1, an element can only have at most one of any kind of pseudo-element at any time. (This means an element can have both a :before and an :after pseudo-element — it just cannot have more than one of each kind.)

As a result, when you have multiple :before rules matching the same element, they will all cascade and apply to a single :before pseudo-element, as with a normal element. In your example, the end result looks like this:

.circle.now:before {
    content: "Now";
    font-size: 19px;
    color: black;
}

As you can see, only the content declaration that has highest precedence (as mentioned, the one that comes last) will take effect — the rest of the declarations are discarded, as is the case with any other CSS property.

This behavior is described in the Selectors section of CSS2.1:

Pseudo-elements behave just like real elements in CSS with the exceptions described below and elsewhere.

This implies that selectors with pseudo-elements work just like selectors for normal elements. It also means the cascade should work the same way. Strangely, CSS2.1 appears to be the only reference; neither css3-selectors nor css3-cascade mention this at all, and it remains to be seen whether it will be clarified in a future specification.

If an element can match more than one selector with the same pseudo-element, and you want all of them to apply somehow, you will need to create additional CSS rules with combined selectors so that you can specify exactly what the browser should do in those cases. I can't provide a complete example including the content property here, since it's not clear for instance whether the symbol or the text should come first. But the selector you need for this combined rule is either .circle.now:before or .now.circle:before — whichever selector you choose is personal preference as both selectors are equivalent, it's only the value of the content property that you will need to define yourself.

If you still need a concrete example, see my answer to this similar question.

The legacy css3-content specification contains a section on inserting multiple ::before and ::after pseudo-elements using a notation that's compatible with the CSS2.1 cascade, but note that that particular document is obsolete — it hasn't been updated since 2003, and no one has implemented that feature in the past decade. The good news is that the abandoned document is actively undergoing a rewrite in the guise of css-content-3 and css-pseudo-4. The bad news is that the multiple pseudo-elements feature is nowhere to be found in either specification, presumably owing, again, to lack of implementer interest.

What is username and password when starting Spring Boot with Tomcat?

Try to take username and password from below code snipet in your project and login and hope this will work.

@Override
    @Bean
    public UserDetailsService userDetailsService() {
        List<UserDetails> users= new ArrayList<UserDetails>();
        users.add(User.withDefaultPasswordEncoder().username("admin").password("admin").roles("USER","ADMIN").build());
        users.add(User.withDefaultPasswordEncoder().username("spring").password("spring").roles("USER").build());
        return new UserDetailsManager(users);
    }

How to unpublish an app in Google Play Developer Console

FYI, they've updated the Google Play developer page again. Now, at the far right, click the vertical ellipsis (like a colon with an extra dot in it). That now has the 'Unpublish App' option.

How to set python variables to true or false?

match_var = a==b

that should more than suffice

you cant use a - in a variable name as it thinks that is match (minus) var

match=1
var=2

print match-var  #prints -1

How to crop an image using C#?

Cropping an image is very easy in C#. However, doing the stuff how are you going to manage the cropping of your image will be a little harder.

Sample below is the way how to crop an image in C#.

var filename = @"c:\personal\images\horizon.png";
var img = Image.FromFile(filename);
var rect = new Rectangle(new Point(0, 0), img.Size);
var cloned = new Bitmap(img).Clone(rect, img.PixelFormat);
var bitmap = new Bitmap(cloned, new Size(50, 50));
cloned.Dispose();

shell script to remove a file if it already exist

A one liner shell script to remove a file if it already exist (based on Jindra Helcl's answer):

[ -f file ] && rm file

or with a variable:

#!/bin/bash

file="/path/to/file.ext"
[ -f $file ] && rm $file

Check if boolean is true?

The first example nearly always wins in my book:

if(foo)
{
}

It's shorter and more concise. Why add an extra check to something when it's absolutely not needed? Just wasting cycles...

I do agree, though, that sometimes the more verbose syntax makes things more readable (which is ultimately more important as long as performance is acceptable) in situations where variables are poorly named.

Convert List to Pandas Dataframe Column

Example:

['Thanks You',
 'Its fine no problem',
 'Are you sure']

code block:

import pandas as pd
df = pd.DataFrame(lst)

Output:

    0
0   Thanks You
1   Its fine no problem
2   Are you sure

It is not recommended to remove the column names of the panda dataframe. but if you still want your data frame without header(as per the format you posted in the question) you can do this:

df = pd.DataFrame(lst)    
df.columns = ['']

Output will be like this:

0   Thanks You
1   Its fine no problem
2   Are you sure

or

df = pd.DataFrame(lst).to_string(header=False)

But the output will be a list instead of a dataframe:

0           Thanks You
1  Its fine no problem
2         Are you sure

Hope this helps!!

How To Launch Git Bash from DOS Command Line?

https://stackoverflow.com/a/33368029/15789

I have posted an answer here.

Open a Windows command window, and execute this script. If there is a change in your working directory, it will open a bash terminal in your working directory, and display the current git status. It keeps the bash window open, by calling exec bash.

If you have multiple projects you may create copies of this script with different project folder, and call it from a main batch script.

how to add values to an array of objects dynamically in javascript?

In Year 2019, we can use Javascript's ES6 Spread syntax to do it concisely and efficiently

data = [...data, {"label": 2, "value": 13}]

Examples

_x000D_
_x000D_
var data = [_x000D_
      {"label" : "1", "value" : 12},_x000D_
      {"label" : "1", "value" : 12},_x000D_
      {"label" : "1", "value" : 12},_x000D_
    ];_x000D_
    _x000D_
data = [...data, {"label" : "2", "value" : 14}] _x000D_
console.log(data)
_x000D_
_x000D_
_x000D_

For your case (i know it was in 2011), we can do it with map() & forEach() like below

_x000D_
_x000D_
var lab = ["1","2","3","4"];_x000D_
var val = [42,55,51,22];_x000D_
_x000D_
//Using forEach()_x000D_
var data = [];_x000D_
val.forEach((v,i) => _x000D_
   data= [...data, {"label": lab[i], "value":v}]_x000D_
)_x000D_
_x000D_
//Using map()_x000D_
var dataMap = val.map((v,i) => _x000D_
 ({"label": lab[i], "value":v})_x000D_
)_x000D_
_x000D_
console.log('data: ', data);_x000D_
console.log('dataMap : ', dataMap);
_x000D_
_x000D_
_x000D_

Why can't I have abstract static methods in C#?

Another respondent (McDowell) said that polymorphism only works for object instances. That should be qualified; there are languages that do treat classes as instances of a "Class" or "Metaclass" type. These languages do support polymorphism for both instance and class (static) methods.

C#, like Java and C++ before it, is not such a language; the static keyword is used explicitly to denote that the method is statically-bound rather than dynamic/virtual.

Giving UIView rounded corners

view.layer.cornerRadius = 25
view.layer.masksToBounds = true

How to efficiently calculate a running standard deviation?

n=int(raw_input("Enter no. of terms:"))

L=[]

for i in range (1,n+1):

    x=float(raw_input("Enter term:"))

    L.append(x)

sum=0

for i in range(n):

    sum=sum+L[i]

avg=sum/n

sumdev=0

for j in range(n):

    sumdev=sumdev+(L[j]-avg)**2

dev=(sumdev/n)**0.5

print "Standard deviation is", dev

Auto start print html page using javascript

The following code must be put at the end of your HTML file so that once the content has loaded, the script will be executed and the window will print.

<script type="text/javascript">
<!--
window.print();
//-->
</script>

Advantages of std::for_each over for loop

The advantage of writing functional for beeing more readable, might not show up when for(...) and for_each(...).

If you utilize all algorithms in functional.h, instead of using for-loops, the code gets a lot more readable;

iterator longest_tree = std::max_element(forest.begin(), forest.end(), ...);
iterator first_leaf_tree = std::find_if(forest.begin(), forest.end(), ...);
std::transform(forest.begin(), forest.end(), firewood.begin(), ...);
std::for_each(forest.begin(), forest.end(), make_plywood);

is much more readable than;

Forest::iterator longest_tree = it.begin();
for (Forest::const_iterator it = forest.begin(); it != forest.end(); ++it{
   if (*it > *longest_tree) {
     longest_tree = it;
   }
}

Forest::iterator leaf_tree = it.begin();
for (Forest::const_iterator it = forest.begin(); it != forest.end(); ++it{
   if (it->type() == LEAF_TREE) {
     leaf_tree  = it;
     break;
   }
}

for (Forest::const_iterator it = forest.begin(), jt = firewood.begin(); 
     it != forest.end(); 
     it++, jt++) {
          *jt = boost::transformtowood(*it);
    }

for (Forest::const_iterator it = forest.begin(); it != forest.end(); ++it{
    std::makeplywood(*it);
}

And that is what I think is so nice, generalize the for-loops to one line functions =)

Remove all html tags from php string

$string = <p>Awesome</p><b> Website</b><i> by Narayan</i>. Thanks for visiting enter code here;
$tags = array("p", "i");

echo preg_replace('#<(' . implode( '|', $tags) . ')(?:[^>]+)?>.*?</\1>#s', '', $string);

Try this

How do I expand the output display to see more columns of a pandas DataFrame?

I used these settings when scale of data is high.

# environment settings: 
pd.set_option('display.max_column',None)
pd.set_option('display.max_rows',None)
pd.set_option('display.max_seq_items',None)
pd.set_option('display.max_colwidth', 500)
pd.set_option('expand_frame_repr', True)

You can refer to the documentation here

Links not going back a directory?

You need to give a relative file path of <a href="../index.html">Home</a>

Alternately you can specify a link from the root of your site with <a href="/pages/en/index.html">Home</a>

.. and . have special meanings in file paths, .. means up one directory and . means current directory.

so <a href="index.html">Home</a> is the same as <a href="./index.html">Home</a>

Change column type in pandas

You have four main options for converting types in pandas:

  1. to_numeric() - provides functionality to safely convert non-numeric types (e.g. strings) to a suitable numeric type. (See also to_datetime() and to_timedelta().)

  2. astype() - convert (almost) any type to (almost) any other type (even if it's not necessarily sensible to do so). Also allows you to convert to categorial types (very useful).

  3. infer_objects() - a utility method to convert object columns holding Python objects to a pandas type if possible.

  4. convert_dtypes() - convert DataFrame columns to the "best possible" dtype that supports pd.NA (pandas' object to indicate a missing value).

Read on for more detailed explanations and usage of each of these methods.


1. to_numeric()

The best way to convert one or more columns of a DataFrame to numeric values is to use pandas.to_numeric().

This function will try to change non-numeric objects (such as strings) into integers or floating point numbers as appropriate.

Basic usage

The input to to_numeric() is a Series or a single column of a DataFrame.

>>> s = pd.Series(["8", 6, "7.5", 3, "0.9"]) # mixed string and numeric values
>>> s
0      8
1      6
2    7.5
3      3
4    0.9
dtype: object

>>> pd.to_numeric(s) # convert everything to float values
0    8.0
1    6.0
2    7.5
3    3.0
4    0.9
dtype: float64

As you can see, a new Series is returned. Remember to assign this output to a variable or column name to continue using it:

# convert Series
my_series = pd.to_numeric(my_series)

# convert column "a" of a DataFrame
df["a"] = pd.to_numeric(df["a"])

You can also use it to convert multiple columns of a DataFrame via the apply() method:

# convert all columns of DataFrame
df = df.apply(pd.to_numeric) # convert all columns of DataFrame

# convert just columns "a" and "b"
df[["a", "b"]] = df[["a", "b"]].apply(pd.to_numeric)

As long as your values can all be converted, that's probably all you need.

Error handling

But what if some values can't be converted to a numeric type?

to_numeric() also takes an errors keyword argument that allows you to force non-numeric values to be NaN, or simply ignore columns containing these values.

Here's an example using a Series of strings s which has the object dtype:

>>> s = pd.Series(['1', '2', '4.7', 'pandas', '10'])
>>> s
0         1
1         2
2       4.7
3    pandas
4        10
dtype: object

The default behaviour is to raise if it can't convert a value. In this case, it can't cope with the string 'pandas':

>>> pd.to_numeric(s) # or pd.to_numeric(s, errors='raise')
ValueError: Unable to parse string

Rather than fail, we might want 'pandas' to be considered a missing/bad numeric value. We can coerce invalid values to NaN as follows using the errors keyword argument:

>>> pd.to_numeric(s, errors='coerce')
0     1.0
1     2.0
2     4.7
3     NaN
4    10.0
dtype: float64

The third option for errors is just to ignore the operation if an invalid value is encountered:

>>> pd.to_numeric(s, errors='ignore')
# the original Series is returned untouched

This last option is particularly useful when you want to convert your entire DataFrame, but don't not know which of our columns can be converted reliably to a numeric type. In that case just write:

df.apply(pd.to_numeric, errors='ignore')

The function will be applied to each column of the DataFrame. Columns that can be converted to a numeric type will be converted, while columns that cannot (e.g. they contain non-digit strings or dates) will be left alone.

Downcasting

By default, conversion with to_numeric() will give you either a int64 or float64 dtype (or whatever integer width is native to your platform).

That's usually what you want, but what if you wanted to save some memory and use a more compact dtype, like float32, or int8?

to_numeric() gives you the option to downcast to either 'integer', 'signed', 'unsigned', 'float'. Here's an example for a simple series s of integer type:

>>> s = pd.Series([1, 2, -7])
>>> s
0    1
1    2
2   -7
dtype: int64

Downcasting to 'integer' uses the smallest possible integer that can hold the values:

>>> pd.to_numeric(s, downcast='integer')
0    1
1    2
2   -7
dtype: int8

Downcasting to 'float' similarly picks a smaller than normal floating type:

>>> pd.to_numeric(s, downcast='float')
0    1.0
1    2.0
2   -7.0
dtype: float32

2. astype()

The astype() method enables you to be explicit about the dtype you want your DataFrame or Series to have. It's very versatile in that you can try and go from one type to the any other.

Basic usage

Just pick a type: you can use a NumPy dtype (e.g. np.int16), some Python types (e.g. bool), or pandas-specific types (like the categorical dtype).

Call the method on the object you want to convert and astype() will try and convert it for you:

# convert all DataFrame columns to the int64 dtype
df = df.astype(int)

# convert column "a" to int64 dtype and "b" to complex type
df = df.astype({"a": int, "b": complex})

# convert Series to float16 type
s = s.astype(np.float16)

# convert Series to Python strings
s = s.astype(str)

# convert Series to categorical type - see docs for more details
s = s.astype('category')

Notice I said "try" - if astype() does not know how to convert a value in the Series or DataFrame, it will raise an error. For example if you have a NaN or inf value you'll get an error trying to convert it to an integer.

As of pandas 0.20.0, this error can be suppressed by passing errors='ignore'. Your original object will be return untouched.

Be careful

astype() is powerful, but it will sometimes convert values "incorrectly". For example:

>>> s = pd.Series([1, 2, -7])
>>> s
0    1
1    2
2   -7
dtype: int64

These are small integers, so how about converting to an unsigned 8-bit type to save memory?

>>> s.astype(np.uint8)
0      1
1      2
2    249
dtype: uint8

The conversion worked, but the -7 was wrapped round to become 249 (i.e. 28 - 7)!

Trying to downcast using pd.to_numeric(s, downcast='unsigned') instead could help prevent this error.


3. infer_objects()

Version 0.21.0 of pandas introduced the method infer_objects() for converting columns of a DataFrame that have an object datatype to a more specific type (soft conversions).

For example, here's a DataFrame with two columns of object type. One holds actual integers and the other holds strings representing integers:

>>> df = pd.DataFrame({'a': [7, 1, 5], 'b': ['3','2','1']}, dtype='object')
>>> df.dtypes
a    object
b    object
dtype: object

Using infer_objects(), you can change the type of column 'a' to int64:

>>> df = df.infer_objects()
>>> df.dtypes
a     int64
b    object
dtype: object

Column 'b' has been left alone since its values were strings, not integers. If you wanted to try and force the conversion of both columns to an integer type, you could use df.astype(int) instead.


4. convert_dtypes()

Version 1.0 and above includes a method convert_dtypes() to convert Series and DataFrame columns to the best possible dtype that supports the pd.NA missing value.

Here "best possible" means the type most suited to hold the values. For example, this a pandas integer type if all of the values are integers (or missing values): an object column of Python integer objects is converted to Int64, a column of NumPy int32 values will become the pandas dtype Int32.

With our object DataFrame df, we get the following result:

>>> df.convert_dtypes().dtypes                                             
a     Int64
b    string
dtype: object

Since column 'a' held integer values, it was converted to the Int64 type (which is capable of holding missing values, unlike int64).

Column 'b' contained string objects, so was changed to pandas' string dtype.

By default, this method will infer the type from object values in each column. We can change this by passing infer_objects=False:

>>> df.convert_dtypes(infer_objects=False).dtypes                          
a    object
b    string
dtype: object

Now column 'a' remained an object column: pandas knows it can be described as an 'integer' column (internally it ran infer_dtype) but didn't infer exactly what dtype of integer it should have so did not convert it. Column 'b' was again converted to 'string' dtype as it was recognised as holding 'string' values.

Change WPF window background image in C# code

What about this:

new ImageBrush(new BitmapImage(new Uri(BaseUriHelper.GetBaseUri(this), "Images/icon.png")))

or alternatively, this:

this.Background = new ImageBrush(new BitmapImage(new Uri(@"pack://application:,,,/myapp;component/Images/icon.png")));

ruby 1.9: invalid byte sequence in UTF-8

Before you use scan, make sure that the requested page's Content-Type header is text/html, since there can be links to things like images which are not encoded in UTF-8. The page could also be non-html if you picked up a href in something like a <link> element. How to check this varies on what HTTP library you are using. Then, make sure the result is only ascii with String#ascii_only? (not UTF-8 because HTML is only supposed to be using ascii, entities can be used otherwise). If both of those tests pass, it is safe to use scan.

When to use async false and async true in ajax function in jquery

  1. When async setting is set to false, a Synchronous call is made instead of an Asynchronous call.
  2. When the async setting of the jQuery AJAX function is set to true then a jQuery Asynchronous call is made. AJAX itself means Asynchronous JavaScript and XML and hence if you make it Synchronous by setting async setting to false, it will no longer be an AJAX call.
  3. for more information please refer this link

Mockito: Inject real objects into private @Autowired fields

I know this is an old question, but we were faced with the same problem when trying to inject Strings. So we invented a JUnit5/Mockito extension that does exactly what you want: https://github.com/exabrial/mockito-object-injection

EDIT:

@InjectionMap
 private Map<String, Object> injectionMap = new HashMap<>();

 @BeforeEach
 public void beforeEach() throws Exception {
  injectionMap.put("securityEnabled", Boolean.TRUE);
 }

 @AfterEach
 public void afterEach() throws Exception {
  injectionMap.clear();
 }

Groovy write to file (newline)

It looks to me, like you're working in windows in which case a new line character in not simply \n but rather \r\n

You can always get the correct new line character through System.getProperty("line.separator") for example.

ECMAScript 6 arrow function that returns an object

You may wonder, why the syntax is valid (but not working as expected):

var func = p => { foo: "bar" }

It's because of JavaScript's label syntax:

So if you transpile the above code to ES5, it should look like:

var func = function (p) {
  foo:
  "bar"; //obviously no return here!
}

Compiling a java program into an executable

The thing you can do is create a .bat that will execute the .jar file created, checking if there is a JRE present.

From Mitch useful link (source)

java -classpath myprogram.jar de.vogella.eclipse.ide.first.MyFirstClass

This can be used into your batch...

apc vs eaccelerator vs xcache

I always used APC with php 5.1 and 5.2, but I had a lot of (random) errors using APC with php 5.3: Strange blank pages, random out-of-memory errors. They all disappeared when I disabled APC. But that was no option, as it is running a high-volume website.

So I tried eaccelerator. So far it has been rock solid and the speed increase is even bigger than with APC. The APC guys really need to spend some time on bugfixing.

If isset $_POST

You can try this:

if (isset($_POST["mail"]) !== false) {
    echo "Yes, mail is set";    
}else{  
    echo "N0, mail is not set";
}

How to go back to previous page if back button is pressed in WebView?

You should the following libraries on your class handle the onBackKeyPressed. canGoBack() checks whether the webview can reference to the previous page. If it is possible then use the goBack() function to reference the previous page (go back).

 @Override
        public void onBackPressed() {
          if( mWebview.canGoBack()){
               mWebview.goBack(); 
           }else{
            //Do something else. like trigger pop up. Add rate app or see more app
           }
  }

What is the first character in the sort order used by Windows Explorer?

I know there is already an answer - and this is an old question - but I was wondering the same thing and after finding this answer I did a little experimentation on my own and had (IMO) a worthwhile addition to the discussion.

The non-visible characters can still be used in a folder name - a placeholder is inserted - but the sort on ASCII value still seems to hold.

I tested on Windows7, holding down the alt-key and typing in the ASCII code using the numeric keypad. I did not test very many, but was successful creating foldernames that started with ASCII 1, ASCII 2, and ASCII 3. Those correspond with SOH, STX and ETX. Respectively it displayed happy face, filled happy face, and filled heart.

I'm not sure if I can duplicate that here - but I will type them in on the next lines and submit.

?foldername

?foldername

?foldername

Create Log File in Powershell

Put this at the top of your file:

$Logfile = "D:\Apps\Logs\$(gc env:computername).log"

Function LogWrite
{
   Param ([string]$logstring)

   Add-content $Logfile -value $logstring
}

Then replace your Write-host calls with LogWrite.

SQL where datetime column equals today's date?

To get all the records where record created date is today's date Use the code after WHERE clause

WHERE  CAST(Submission_date AS DATE) = CAST( curdate() AS DATE)

MySQL - ERROR 1045 - Access denied

I had the same error, but it was because password_expired was set to Y. You can fix that issue by following the same approach as the currently accepted answer, but instead executing the MySQL query:

UPDATE mysql.user SET password_expired = 'N' WHERE User='root';

Fastest way to check a string is alphanumeric in Java

A regex will probably be quite efficient, because you would specify ranges: [0-9a-zA-Z]. Assuming the implementation code for regexes is efficient, this would simply require an upper and lower bound comparison for each range. Here's basically what a compiled regex should do:

boolean isAlphanumeric(String str) {
    for (int i=0; i<str.length(); i++) {
        char c = str.charAt(i);
        if (c < 0x30 || (c >= 0x3a && c <= 0x40) || (c > 0x5a && c <= 0x60) || c > 0x7a)
            return false;
    }

    return true;
}

I don't see how your code could be more efficient than this, because every character will need to be checked, and the comparisons couldn't really be any simpler.

SQL keys, MUL vs PRI vs UNI

DESCRIBE <table>; 

This is acutally a shortcut for:

SHOW COLUMNS FROM <table>;

In any case, there are three possible values for the "Key" attribute:

  1. PRI
  2. UNI
  3. MUL

The meaning of PRI and UNI are quite clear:

  • PRI => primary key
  • UNI => unique key

The third possibility, MUL, (which you asked about) is basically an index that is neither a primary key nor a unique key. The name comes from "multiple" because multiple occurrences of the same value are allowed. Straight from the MySQL documentation:

If Key is MUL, the column is the first column of a nonunique index in which multiple occurrences of a given value are permitted within the column.

There is also a final caveat:

If more than one of the Key values applies to a given column of a table, Key displays the one with the highest priority, in the order PRI, UNI, MUL.

As a general note, the MySQL documentation is quite good. When in doubt, check it out!

How do I wait for an asynchronously dispatched block to finish?

dispatch_semaphore_t sema = dispatch_semaphore_create(0);
[object blockToExecute:^{
    // ... your code to execute
    dispatch_semaphore_signal(sema);
}];

while (dispatch_semaphore_wait(semaphore, DISPATCH_TIME_NOW)) {
    [[NSRunLoop currentRunLoop]
        runUntilDate:[NSDate dateWithTimeIntervalSinceNow:0]];
}

This did it for me.

Missing Microsoft RDLC Report Designer in Visual Studio

I had the same problem, after install the MS VS Community 2015, I didn't find the RDLC files neither the Report Viewer component, I solve the problem by going in the Control Panel (Windows) -> Programs -> Try to uninstall the MS VS Community and choose MODIFY, in this moment you will be able to Check the Microsoft SQL Server Data Tools.

That is it!

IOS - How to segue programmatically using swift

Another option is to use modal segue

STEP 1: Go to the storyboard, and give the View Controller a Storyboard ID. You can find where to change the storyboard ID in the Identity Inspector on the right. Lets call the storyboard ID ModalViewController

STEP 2: Open up the 'sender' view controller (let's call it ViewController) and add this code to it

public class ViewController {
  override func viewDidLoad() {
    showModalView()
  }

  func showModalView() {
    if let mvc = UIStoryboard(name: "Main", bundle: nil).instantiateViewController(withIdentifier: "ModalViewController") as? ModalViewController {
      self.present(mvc, animated: true, completion: nil)
    }
  }
}

Note that the View Controller we want to open is also called ModalViewController

STEP 3: To close ModalViewController, add this to it

public class ModalViewController {
   @IBAction func closeThisViewController(_ sender: Any?) {
      self.presentingViewController?.dismiss(animated: true, completion: nil)
   }
}

JQuery Validate Dropdown list

I have modified your code a little. Here's a working version (for me):

    <select name="dd1" id="dd1">
       <option value="none">None</option>
       <option value="o1">option 1</option>
       <option value="o2">option 2</option>
       <option value="o3">option 3</option>
    </select>  
    <div style="color:red;" id="msg_id"></div>

<script>
    $('#everything').submit(function(e){ 
        var department = $("#msg_id");
        var msg = "Please select Department";
            if ($('#dd1').val() == "") {
                department.append(msg);
                e.preventDefault();
                return false;
            }
        });
 </script>

PHP CURL Enable Linux

It dipends on which distribution you are in general but... You have to install the php-curl module and then enable it on php.ini like you did in windows. Once you are done remember to restart apache demon!

jQuery remove selected option from this

 $('#some_select_box').click(function() {
     $(this).find('option:selected').remove();
 });

Using the find method.

Double array initialization in Java

You can initialize an array by writing actual values it holds in curly braces on the right hand side like:

String[] strArr = { "one", "two", "three"};
int[] numArr = { 1, 2, 3};

In the same manner two-dimensional array or array-of-arrays holds an array as a value, so:

String strArrayOfArrays = { {"a", "b", "c"}, {"one", "two", "three"} };

Your example shows exactly that

double m[][] = {
    {0*0,1*0,2*0,3*0},
    {0*1,1*1,2*1,3*1},
    {0*2,1*2,2*2,3*2},
    {0*3,1*3,2*3,3*3}
};

But also the multiplication of number will also be performed and its the same as:

double m[][] = { {0, 0, 0, 0}, {0, 1, 2, 3}, {0, 2, 4, 6}, {0, 3, 6, 9} };

How can I quickly and easily convert spreadsheet data to JSON?

Assuming you really mean easiest and are not necessarily looking for a way to do this programmatically, you can do this:

  1. Add, if not already there, a row of "column Musicians" to the spreadsheet. That is, if you have data in columns such as:

    Rory Gallagher      Guitar
    Gerry McAvoy        Bass
    Rod de'Ath          Drums
    Lou Martin          Keyboards
    Donkey Kong Sioux   Self-Appointed Semi-official Stomper
    

    Note: you might want to add "Musician" and "Instrument" in row 0 (you might have to insert a row there)

  2. Save the file as a CSV file.

  3. Copy the contents of the CSV file to the clipboard

  4. Go to http://www.convertcsv.com/csv-to-json.htm

  5. Verify that the "First row is column names" checkbox is checked

  6. Paste the CSV data into the content area

  7. Mash the "Convert CSV to JSON" button

    With the data shown above, you will now have:

    [
      {
        "MUSICIAN":"Rory Gallagher",
        "INSTRUMENT":"Guitar"
      },
      {
        "MUSICIAN":"Gerry McAvoy",
        "INSTRUMENT":"Bass"
      },
      {
        "MUSICIAN":"Rod D'Ath",
        "INSTRUMENT":"Drums"
      },
      {
        "MUSICIAN":"Lou Martin",
        "INSTRUMENT":"Keyboards"
      }
      {
        "MUSICIAN":"Donkey Kong Sioux",
        "INSTRUMENT":"Self-Appointed Semi-Official Stomper"
      }
    ]
    

    With this simple/minimalistic data, it's probably not required, but with large sets of data, it can save you time and headache in the proverbial long run by checking this data for aberrations and abnormalcy.

  8. Go here: http://jsonlint.com/

  9. Paste the JSON into the content area

  10. Pres the "Validate" button.

If the JSON is good, you will see a "Valid JSON" remark in the Results section below; if not, it will tell you where the problem[s] lie so that you can fix it/them.

Java stack overflow error - how to increase the stack size in Eclipse?

Look at Morris in-order tree traversal which uses constant space and runs in O(n) (up to 3 times longer than your normal recursive traversal - but you save hugely on space). If the nodes are modifiable, than you could save the calculated result of the sub-tree as you backtrack to its root (by writing directly to the Node).

How do I tell Spring Boot which main class to use for the executable jar?

For those using Gradle (instead of Maven), referencing here:

The main class can also be configured explicitly using the task’s mainClassName property:

bootJar {
    mainClassName = 'com.example.ExampleApplication'
}

Alternatively, the main class name can be configured project-wide using the mainClassName property of the Spring Boot DSL:

springBoot {
    mainClassName = 'com.example.ExampleApplication'
}

Java executors: how to be notified, without blocking, when a task completes?

Define a callback interface to receive whatever parameters you want to pass along in the completion notification. Then invoke it at the end of the task.

You could even write a general wrapper for Runnable tasks, and submit these to ExecutorService. Or, see below for a mechanism built into Java 8.

class CallbackTask implements Runnable {

  private final Runnable task;

  private final Callback callback;

  CallbackTask(Runnable task, Callback callback) {
    this.task = task;
    this.callback = callback;
  }

  public void run() {
    task.run();
    callback.complete();
  }

}

With CompletableFuture, Java 8 included a more elaborate means to compose pipelines where processes can be completed asynchronously and conditionally. Here's a contrived but complete example of notification.

import java.util.concurrent.CompletableFuture;
import java.util.concurrent.ThreadLocalRandom;
import java.util.concurrent.TimeUnit;

public class GetTaskNotificationWithoutBlocking {

  public static void main(String... argv) throws Exception {
    ExampleService svc = new ExampleService();
    GetTaskNotificationWithoutBlocking listener = new GetTaskNotificationWithoutBlocking();
    CompletableFuture<String> f = CompletableFuture.supplyAsync(svc::work);
    f.thenAccept(listener::notify);
    System.out.println("Exiting main()");
  }

  void notify(String msg) {
    System.out.println("Received message: " + msg);
  }

}

class ExampleService {

  String work() {
    sleep(7000, TimeUnit.MILLISECONDS); /* Pretend to be busy... */
    char[] str = new char[5];
    ThreadLocalRandom current = ThreadLocalRandom.current();
    for (int idx = 0; idx < str.length; ++idx)
      str[idx] = (char) ('A' + current.nextInt(26));
    String msg = new String(str);
    System.out.println("Generated message: " + msg);
    return msg;
  }

  public static void sleep(long average, TimeUnit unit) {
    String name = Thread.currentThread().getName();
    long timeout = Math.min(exponential(average), Math.multiplyExact(10, average));
    System.out.printf("%s sleeping %d %s...%n", name, timeout, unit);
    try {
      unit.sleep(timeout);
      System.out.println(name + " awoke.");
    } catch (InterruptedException abort) {
      Thread.currentThread().interrupt();
      System.out.println(name + " interrupted.");
    }
  }

  public static long exponential(long avg) {
    return (long) (avg * -Math.log(1 - ThreadLocalRandom.current().nextDouble()));
  }

}

Why is exception.printStackTrace() considered bad practice?

Printing the exception's stack trace in itself doesn't constitute bad practice, but only printing the stace trace when an exception occurs is probably the issue here -- often times, just printing a stack trace is not enough.

Also, there's a tendency to suspect that proper exception handling is not being performed if all that is being performed in a catch block is a e.printStackTrace. Improper handling could mean at best an problem is being ignored, and at worst a program that continues executing in an undefined or unexpected state.

Example

Let's consider the following example:

try {
  initializeState();

} catch (TheSkyIsFallingEndOfTheWorldException e) {
  e.printStackTrace();
}

continueProcessingAssumingThatTheStateIsCorrect();

Here, we want to do some initialization processing before we continue on to some processing that requires that the initialization had taken place.

In the above code, the exception should have been caught and properly handled to prevent the program from proceeding to the continueProcessingAssumingThatTheStateIsCorrect method which we could assume would cause problems.

In many instances, e.printStackTrace() is an indication that some exception is being swallowed and processing is allowed to proceed as if no problem every occurred.

Why has this become a problem?

Probably one of the biggest reason that poor exception handling has become more prevalent is due to how IDEs such as Eclipse will auto-generate code that will perform a e.printStackTrace for the exception handling:

try {
  Thread.sleep(1000);
} catch (InterruptedException e) {
  // TODO Auto-generated catch block
  e.printStackTrace();
}

(The above is an actual try-catch auto-generated by Eclipse to handle an InterruptedException thrown by Thread.sleep.)

For most applications, just printing the stack trace to standard error is probably not going to be sufficient. Improper exception handling could in many instances lead to an application running in a state that is unexpected and could be leading to unexpected and undefined behavior.

What are the differences in die() and exit() in PHP?

Functionally, they are identical. So to choose which one to use is totally a personal preference. Semantically in English, they are different. Die sounds negative. When I have a function which returns JSON data to the client and terminate the program, it can be awful if I call this function jsonDie(), and it is more appropriate to call it jsonExit(). For that reason, I always use exit instead of die.

Convert Python dictionary to JSON array

If you use Python 2, don't forget to add the UTF-8 file encoding comment on the first line of your script.

# -*- coding: UTF-8 -*-

This will fix some Unicode problems and make your life easier.

Mask for an Input to allow phone numbers?

<input type="text" formControlName="gsm" (input)="formatGsm($event.target.value)">

formatGsm(inputValue: String): String {
  const value = inputValue.replace(/[^0-9]/g, ''); // remove except digits
  let format = '(***) *** ** **'; // You can change format

  for (let i = 0; i < value.length; i++) {
    format = format.replace('*', value.charAt(i));
  }

  if (format.indexOf('*') >= 0) {
    format = format.substring(0, format.indexOf('*'));
  }

  return format.trim();
}

How to filter by IP address in Wireshark?

Other answers already cover how to filter by an address, but if you would like to exclude an address use

ip.addr < 192.168.0.11

How to change Angular CLI favicon

For Angular 6, put favicon.png of size 32x32 in the asset folder and change the path in index.html. Then,

<link rel="icon" type="image/x-icon" href="./assets/favicon.png">

How to iterate over a column vector in Matlab?

If you just want to apply a function to each element and put the results in an output array, you can use arrayfun.

As others have pointed out, for most operations, it's best to avoid loops in MATLAB and vectorise your code instead.

Typescript import/as vs import/require?

import * as express from "express";

This is the suggested way of doing it because it is the standard for JavaScript (ES6/2015) since last year.

In any case, in your tsconfig.json file, you should target the module option to commonjs which is the format supported by nodejs.

Importing a long list of constants to a Python file

Python isn't preprocessed. You can just create a file myconstants.py:

MY_CONSTANT = 50

And importing them will just work:

import myconstants
print myconstants.MY_CONSTANT * 2

Return list using select new in LINQ

try this solution for me its working

     public List<ProjectInfo> GetProjectForCombo()
      {
    using (MyDataContext db = new MyDataContext 
    (DBHelper.GetConnectionString()))
         {
        return  (from pro in db.Projects
                    select new { query  }.query).ToList();
        }
      }

Angular 4: InvalidPipeArgument: '[object Object]' for pipe 'AsyncPipe'

I found another solution to get the data. according to the documentation Please check documentation link

In service file add following.

import { Injectable } from '@angular/core';
import { AngularFireDatabase } from 'angularfire2/database';

@Injectable()
export class MoviesService {

  constructor(private db: AngularFireDatabase) {}
  getMovies() {
    this.db.list('/movies').valueChanges();
  }
}

In Component add following.

import { Component, OnInit } from '@angular/core';
import { MoviesService } from './movies.service';

@Component({
  selector: 'app-movies',
  templateUrl: './movies.component.html',
  styleUrls: ['./movies.component.css']
})
export class MoviesComponent implements OnInit {
  movies$;

  constructor(private moviesDb: MoviesService) { 
   this.movies$ = moviesDb.getMovies();
 }

In your html file add following.

<li  *ngFor="let m of movies$ | async">{{ m.name }} </li>

Clear dropdown using jQuery Select2

This solved my problem in version 3.5.2.

$remote.empty().append(new Option()).trigger('change');

According to this issue you need an empty option inside select tag for the placeholder to show up.

str.startswith with a list of strings to test for

str.startswith allows you to supply a tuple of strings to test for:

if link.lower().startswith(("js", "catalog", "script", "katalog")):

From the docs:

str.startswith(prefix[, start[, end]])

Return True if string starts with the prefix, otherwise return False. prefix can also be a tuple of prefixes to look for.

Below is a demonstration:

>>> "abcde".startswith(("xyz", "abc"))
True
>>> prefixes = ["xyz", "abc"]
>>> "abcde".startswith(tuple(prefixes)) # You must use a tuple though
True
>>>

Freezing Row 1 and Column A at the same time

Select cell B2 and click "Freeze Panes" this will freeze Row 1 and Column A.

For future reference, selecting Freeze Panes in Excel will freeze the rows above your selected cell and the columns to the left of your selected cell. For example, to freeze rows 1 and 2 and column A, you could select cell B3 and click Freeze Panes. You could also freeze columns A and B and row 1, by selecting cell C2 and clicking "Freeze Panes".

Visual Aid on Freeze Panes in Excel 2010 - http://www.dummies.com/how-to/content/how-to-freeze-panes-in-an-excel-2010-worksheet.html

Microsoft Reference Guide (More Complicated, but resourceful none the less) - http://office.microsoft.com/en-us/excel-help/freeze-or-lock-rows-and-columns-HP010342542.aspx

Using number as "index" (JSON)

First off, it's not JSON: JSON mandates that all keys must be strings.

Secondly, regular arrays do what you want:

var Game = {
  status: [
    [
      "val",
      "val",
      "val"
    ],
    [
      "val",
      "val",
      "val"
    ]
  }

will work, if you use Game.status[0][0]. You cannot use numbers with the dot notation (.0).

Alternatively, you can quote the numbers (i.e. { "0": "val" }...); you will have plain objects instead of Arrays, but the same syntax will work.

open a url on click of ok button in android

    Button imageLogo = (Button)findViewById(R.id.iv_logo);
    imageLogo.setOnClickListener(new OnClickListener() {

        @Override
        public void onClick(View v) {
            // TODO Auto-generated method stub
            String url = "http://www.gobloggerslive.com";

            Intent i = new Intent(Intent.ACTION_VIEW);
            i.setData(Uri.parse(url));
            startActivity(i);
        }
    });

How to make a simple image upload using Javascript/HTML

Try this, It supports multi file uploading,

$('#multi_file_upload').change(function(e) {
    var file_id = e.target.id;

    var file_name_arr = new Array();
    var process_path = site_url + 'public/uploads/';

    for (i = 0; i < $("#" + file_id).prop("files").length; i++) {

        var form_data = new FormData();
        var file_data = $("#" + file_id).prop("files")[i];
        form_data.append("file_name", file_data);

        if (check_multifile_logo($("#" + file_id).prop("files")[i]['name'])) {
            $.ajax({
                //url         :   site_url + "inc/upload_image.php?width=96&height=60&show_small=1",
                url: site_url + "inc/upload_contact_info.php",
                cache: false,
                contentType: false,
                processData: false,
                async: false,
                data: form_data,
                type: 'post',
                success: function(data) {
                    // display image
                }
            });
        } else {
            $("#" + html_div).html('');
            alert('We only accept JPG, JPEG, PNG, GIF and BMP files');
        }

    }
});

function check_multifile_logo(file) {
    var extension = file.substr((file.lastIndexOf('.') + 1))
    if (extension === 'jpg' || extension === 'jpeg' || extension === 'gif' || extension === 'png' || extension === 'bmp') {
        return true;
    } else {
        return false;
    }
}

Here #multi_file_upload is the ID of image upload field.

Uncompress tar.gz file

Use -C option of tar:

tar zxvf <yourfile>.tar.gz -C /usr/src/

and then, the content of the tar should be in:

/usr/src/<yourfile>

How do I get data from a table?

in this code data is a two dimensional array of table data

let oTable = document.getElementById('datatable-id');
let data = [...oTable.rows].map(t => [...t.children].map(u => u.innerText))

MySQL "WITH" clause

You might be interested in somethinkg like this:

select * from (
    select * from table
) as Subquery

What is a plain English explanation of "Big O" notation?

If I want to explain this to 6 years old child I will start to draw some functions f(x) = x and f(x) = x^2 for example and ask a child which function will be the upper function on the top of the page. Then we will proceed with drawing and see that x^2 wins. "Who wins" actually is the function which grows faster when x tends to infinity. So "function x is in Big O of x^2" means that x grows slower than x^2 when x tends to infinity. The same can be done when x tends to 0. If we draw these two function for x from 0 to 1 x will be an upper function, so "function x^2 is in Big O of x for x tends to 0". When the child will get older I add that really Big O can be a function which grows not faster but the same way as given function. Moreover constant is discarded. So 2x is in Big O of x.

GitLab remote: HTTP Basic: Access denied and fatal Authentication

When the Windows Credential Manager asks for your credentials to access GitLab, those are username and password you use when accessing GitLab. EG: use your email and password.

How do I pass command line arguments to a Node.js program?

No Libs with Flags Formatted into a Simple Object

function getArgs () {
    const args = {};
    process.argv
        .slice(2, process.argv.length)
        .forEach( arg => {
        // long arg
        if (arg.slice(0,2) === '--') {
            const longArg = arg.split('=');
            const longArgFlag = longArg[0].slice(2,longArg[0].length);
            const longArgValue = longArg.length > 1 ? longArg[1] : true;
            args[longArgFlag] = longArgValue;
        }
        // flags
        else if (arg[0] === '-') {
            const flags = arg.slice(1,arg.length).split('');
            flags.forEach(flag => {
            args[flag] = true;
            });
        }
    });
    return args;
}
const args = getArgs();
console.log(args);

Examples

Simple

input

node test.js -D --name=Hello

output

{ D: true, name: 'Hello' }

Real World

input

node config/build.js -lHRs --ip=$HOST --port=$PORT --env=dev

output

{ 
  l: true,
  H: true,
  R: true,
  s: true,
  ip: '127.0.0.1',
  port: '8080',
  env: 'dev'
}

Npm Please try using this command again as root/administrator

This worked for me, if your package.json is not too big you can do this:

  • Signout then signin.
  • Delete node_modules.
  • npm install again.

How do you compare structs for equality in C?

It depends on whether the question you are asking is:

  1. Are these two structs the same object?
  2. Do they have the same value?

To find out if they are the same object, compare pointers to the two structs for equality. If you want to find out in general if they have the same value you have to do a deep comparison. This involves comparing all the members. If the members are pointers to other structs you need to recurse into those structs too.

In the special case where the structs do not contain pointers you can do a memcmp to perform a bitwise comparison of the data contained in each without having to know what the data means.

Make sure you know what 'equals' means for each member - it is obvious for ints but more subtle when it comes to floating-point values or user-defined types.

What replaces cellpadding, cellspacing, valign, and align in HTML5 tables?

On particular table

_x000D_
_x000D_
<table style="border-collapse: separate; border-spacing: 10px;" >_x000D_
    <tr>_x000D_
      <td>Hi</td>_x000D_
      <td>Hello</td>_x000D_
    <tr/>_x000D_
    <tr>_x000D_
      <td>Hola</td>_x000D_
      <td>Oi!</td>_x000D_
    <tr/>_x000D_
</table>
_x000D_
_x000D_
_x000D_

How can I detect when an Android application is running in the emulator?

My recommendation:

try this from github.

Easy to detect android emulator

How to use with an Example:

EmulatorDetector.with(this)
                .setCheckTelephony(true)
                .addPackageName("com.bluestacks")
                .setDebug(true)
                .detect(new EmulatorDetector.OnEmulatorDetectorListener() {
                    @Override
                    public void onResult(boolean isEmulator) {
                        if(isEmulator){
                         // Do your work
                        }
                        else{
                        // Not emulator and do your work
                        }
                    }
                });

How do I add a Maven dependency in Eclipse?

You need to be using a Maven plugin for Eclipse in order to do this properly. The m2e plugin is built into the latest version of Eclipse, and does a decent if not perfect job of integrating Maven into the IDE. You will want to create your project as a 'Maven Project'. Alternatively you can import an existing Maven POM into your workspace to automatically create projects. Once you have your Maven project in the IDE, simply open up the POM and add your dependency to it.

Now, if you do not have a Maven plugin for Eclipse, you will need to get the jar(s) for the dependency in question and manually add them as classpath references to your project. This could get unpleasant as you will need not just the top level JAR, but all its dependencies as well.

Basically, I recommend you get a decent Maven plugin for Eclipse and let it handle the dependency management for you.

how to pass variable from shell script to sqlplus

You appear to have a heredoc containing a single SQL*Plus command, though it doesn't look right as noted in the comments. You can either pass a value in the heredoc:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql BUILDING
exit;
EOF

or if BUILDING is $2 in your script:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql $2
exit;
EOF

If your file.sql had an exit at the end then it would be even simpler as you wouldn't need the heredoc:

sqlplus -S user/pass@localhost @/opt/D2RQ/file.sql $2

In your SQL you can then refer to the position parameters using substitution variables:

...
}',SEM_Models('&1'),NULL,
...

The &1 will be replaced with the first value passed to the SQL script, BUILDING; because that is a string it still needs to be enclosed in quotes. You might want to set verify off to stop if showing you the substitutions in the output.


You can pass multiple values, and refer to them sequentially just as you would positional parameters in a shell script - the first passed parameter is &1, the second is &2, etc. You can use substitution variables anywhere in the SQL script, so they can be used as column aliases with no problem - you just have to be careful adding an extra parameter that you either add it to the end of the list (which makes the numbering out of order in the script, potentially) or adjust everything to match:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql total_count BUILDING
exit;
EOF

or:

sqlplus -S user/pass@localhost << EOF
@/opt/D2RQ/file.sql total_count $2
exit;
EOF

If total_count is being passed to your shell script then just use its positional parameter, $4 or whatever. And your SQL would then be:

SELECT COUNT(*) as &1
FROM TABLE(SEM_MATCH(
'{
        ?s rdf:type :ProcessSpec .
        ?s ?p ?o
}',SEM_Models('&2'),NULL,
SEM_ALIASES(SEM_ALIAS('','http://VISION/DataSource/SEMANTIC_CACHE#')),NULL));

If you pass a lot of values you may find it clearer to use the positional parameters to define named parameters, so any ordering issues are all dealt with at the start of the script, where they are easier to maintain:

define MY_ALIAS = &1
define MY_MODEL = &2

SELECT COUNT(*) as &MY_ALIAS
FROM TABLE(SEM_MATCH(
'{
        ?s rdf:type :ProcessSpec .
        ?s ?p ?o
}',SEM_Models('&MY_MODEL'),NULL,
SEM_ALIASES(SEM_ALIAS('','http://VISION/DataSource/SEMANTIC_CACHE#')),NULL));

From your separate question, maybe you just wanted:

SELECT COUNT(*) as &1
FROM TABLE(SEM_MATCH(
'{
        ?s rdf:type :ProcessSpec .
        ?s ?p ?o
}',SEM_Models('&1'),NULL,
SEM_ALIASES(SEM_ALIAS('','http://VISION/DataSource/SEMANTIC_CACHE#')),NULL));

... so the alias will be the same value you're querying on (the value in $2, or BUILDING in the original part of the answer). You can refer to a substitution variable as many times as you want.

That might not be easy to use if you're running it multiple times, as it will appear as a header above the count value in each bit of output. Maybe this would be more parsable later:

select '&1' as QUERIED_VALUE, COUNT(*) as TOTAL_COUNT

If you set pages 0 and set heading off, your repeated calls might appear in a neat list. You might also need to set tab off and possibly use rpad('&1', 20) or similar to make that column always the same width. Or get the results as CSV with:

select '&1' ||','|| COUNT(*)

Depends what you're using the results for...

Find an element by class name, from a known parent element

var element = $("#parentDiv .myClassNameOfInterest")

How to add items to array in nodejs

Check out Javascript's Array API for details on the exact syntax for Array methods. Modifying your code to use the correct syntax would be:

var array = [];
calendars.forEach(function(item) {
    array.push(item.id);
});

console.log(array);

You can also use the map() method to generate an Array filled with the results of calling the specified function on each element. Something like:

var array = calendars.map(function(item) {
    return item.id;
});

console.log(array);

And, since ECMAScript 2015 has been released, you may start seeing examples using let or const instead of var and the => syntax for creating functions. The following is equivalent to the previous example (except it may not be supported in older node versions):

let array = calendars.map(item => item.id);
console.log(array);

eslint: error Parsing error: The keyword 'const' is reserved

If using Visual Code one option is to add this to the settings.json file:

"eslint.options": {
    "useEslintrc": false,
    "parserOptions": {
        "ecmaVersion": 2017
    },
    "env": {
        "es6": true
    }
}

UDP vs TCP, how much faster is it?

The network setup is crucial for any measurements. It makes a huge difference, if you are communicating via sockets on your local machine or with the other end of the world.

Three things I want to add to the discussion:

  1. You can find here a very good article about TCP vs. UDP in the context of game development.
  2. Additionally, iperf (jperf enhance iperf with a GUI) is a very nice tool for answering your question yourself by measuring.
  3. I implemented a benchmark in Python (see this SO question). In average of 10^6 iterations the difference for sending 8 bytes is about 1-2 microseconds for UDP.

How can I obfuscate (protect) JavaScript?

Dean Edward's Packer is an excellent obfuscator, though it primarily obfuscates the code, not any string elements you may have within your code.

See: Online Javascript Compression Tool and select Packer (Dean Edwards) from the dropdown

Android Studio Stuck at Gradle Download on create new project

Invalidate Caches and Restart

It worked for me.

C# Example of AES256 encryption using System.Security.Cryptography.Aes

Maybe this example listed here can help you out. Statement from the author

about 24 lines of code to encrypt, 23 to decrypt

Due to the fact that the link in the original posting is dead - here the needed code parts (c&p without any change to the original source)

  /*
  Copyright (c) 2010 <a href="http://www.gutgames.com">James Craig</a>
  
  Permission is hereby granted, free of charge, to any person obtaining a copy
  of this software and associated documentation files (the "Software"), to deal
  in the Software without restriction, including without limitation the rights
  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
  copies of the Software, and to permit persons to whom the Software is
  furnished to do so, subject to the following conditions:
  
  The above copyright notice and this permission notice shall be included in
  all copies or substantial portions of the Software.
  
  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
  THE SOFTWARE.*/
   
  #region Usings
  using System;
  using System.IO;
  using System.Security.Cryptography;
  using System.Text;
  #endregion
   
  namespace Utilities.Encryption
  {
      /// <summary>
      /// Utility class that handles encryption
      /// </summary>
      public static class AESEncryption
      {
          #region Static Functions
   
          /// <summary>
          /// Encrypts a string
          /// </summary>
          /// <param name="PlainText">Text to be encrypted</param>
          /// <param name="Password">Password to encrypt with</param>
          /// <param name="Salt">Salt to encrypt with</param>
          /// <param name="HashAlgorithm">Can be either SHA1 or MD5</param>
          /// <param name="PasswordIterations">Number of iterations to do</param>
          /// <param name="InitialVector">Needs to be 16 ASCII characters long</param>
          /// <param name="KeySize">Can be 128, 192, or 256</param>
          /// <returns>An encrypted string</returns>
          public static string Encrypt(string PlainText, string Password,
              string Salt = "Kosher", string HashAlgorithm = "SHA1",
              int PasswordIterations = 2, string InitialVector = "OFRna73m*aze01xY",
              int KeySize = 256)
          {
              if (string.IsNullOrEmpty(PlainText))
                  return "";
              byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector);
              byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt);
              byte[] PlainTextBytes = Encoding.UTF8.GetBytes(PlainText);
              PasswordDeriveBytes DerivedPassword = new PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations);
              byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8);
              RijndaelManaged SymmetricKey = new RijndaelManaged();
              SymmetricKey.Mode = CipherMode.CBC;
              byte[] CipherTextBytes = null;
              using (ICryptoTransform Encryptor = SymmetricKey.CreateEncryptor(KeyBytes, InitialVectorBytes))
              {
                  using (MemoryStream MemStream = new MemoryStream())
                  {
                      using (CryptoStream CryptoStream = new CryptoStream(MemStream, Encryptor, CryptoStreamMode.Write))
                      {
                          CryptoStream.Write(PlainTextBytes, 0, PlainTextBytes.Length);
                          CryptoStream.FlushFinalBlock();
                          CipherTextBytes = MemStream.ToArray();
                          MemStream.Close();
                          CryptoStream.Close();
                      }
                  }
              }
              SymmetricKey.Clear();
              return Convert.ToBase64String(CipherTextBytes);
          }
   
          /// <summary>
          /// Decrypts a string
          /// </summary>
          /// <param name="CipherText">Text to be decrypted</param>
          /// <param name="Password">Password to decrypt with</param>
          /// <param name="Salt">Salt to decrypt with</param>
          /// <param name="HashAlgorithm">Can be either SHA1 or MD5</param>
          /// <param name="PasswordIterations">Number of iterations to do</param>
          /// <param name="InitialVector">Needs to be 16 ASCII characters long</param>
          /// <param name="KeySize">Can be 128, 192, or 256</param>
          /// <returns>A decrypted string</returns>
          public static string Decrypt(string CipherText, string Password,
              string Salt = "Kosher", string HashAlgorithm = "SHA1",
              int PasswordIterations = 2, string InitialVector = "OFRna73m*aze01xY",
              int KeySize = 256)
          {
              if (string.IsNullOrEmpty(CipherText))
                  return "";
              byte[] InitialVectorBytes = Encoding.ASCII.GetBytes(InitialVector);
              byte[] SaltValueBytes = Encoding.ASCII.GetBytes(Salt);
              byte[] CipherTextBytes = Convert.FromBase64String(CipherText);
              PasswordDeriveBytes DerivedPassword = new PasswordDeriveBytes(Password, SaltValueBytes, HashAlgorithm, PasswordIterations);
              byte[] KeyBytes = DerivedPassword.GetBytes(KeySize / 8);
              RijndaelManaged SymmetricKey = new RijndaelManaged();
              SymmetricKey.Mode = CipherMode.CBC;
              byte[] PlainTextBytes = new byte[CipherTextBytes.Length];
              int ByteCount = 0;
              using (ICryptoTransform Decryptor = SymmetricKey.CreateDecryptor(KeyBytes, InitialVectorBytes))
              {
                  using (MemoryStream MemStream = new MemoryStream(CipherTextBytes))
                  {
                      using (CryptoStream CryptoStream = new CryptoStream(MemStream, Decryptor, CryptoStreamMode.Read))
                      {
   
                          ByteCount = CryptoStream.Read(PlainTextBytes, 0, PlainTextBytes.Length);
                          MemStream.Close();
                          CryptoStream.Close();
                      }
                  }
              }
              SymmetricKey.Clear();
              return Encoding.UTF8.GetString(PlainTextBytes, 0, ByteCount);
          }
   
          #endregion
      }
  }

Stopping a JavaScript function when a certain condition is met

use return for this

if(i==1) { 
    return; //stop the execution of function
}

//keep on going

Get div's offsetTop positions in React

A better solution with ref to avoid findDOMNode that is discouraged.

...
onScroll() {
    let offsetTop  = this.instance.getBoundingClientRect().top;
}
...
render() {
...
<Component ref={(el) => this.instance = el } />
...

Java String declaration

String s1 = "Welcome"; // Does not create a new instance  
String s2 = new String("Welcome"); // Creates two objects and one reference variable  

How to filter rows in pandas by regex

There is already a string handling function Series.str.startswith(). You should try foo[foo.b.str.startswith('f')].

Result:

    a   b
1   2   foo
2   3   fat

I think what you expect.

Alternatively you can use contains with regex option. For example:

foo[foo.b.str.contains('oo', regex= True, na=False)]

Result:

    a   b
1   2   foo

na=False is to prevent Errors in case there is nan, null etc. values

How to identify unused CSS definitions from multiple CSS files in a project

Google Chrome Developer Tools has (a currently experimental) feature called CSS Overview which will allow you to find unused CSS rules.

To enable it follow these steps:

  1. Open up DevTools (Command+Option+I on Mac; Control+Shift+I on Windows)
  2. Head over to DevTool Settings (Function+F1 on Mac; F1 on Windows)
  3. Click open the Experiments section
  4. Enable the CSS Overview option

enter image description here

SQL Query for Student mark functionality

I like the simple solution using windows functions:

select t.*
from (select student.*, su.subname, max(mark) over (partition by subid) as maxmark
      from marks m join
           students st
           on m.stid = st.stid join
           subject su
           on m.subid = su.subid
     ) t
where t.mark = maxmark

Or, alternatively:

select t.*
from (select student.*, su.subname, rank(mark) over (partition by subid order by mark desc) as markseqnum
      from marks m join
           students st
           on m.stid = st.stid join
           subject su
           on m.subid = su.subid
     ) t
where markseqnum = 1

How do you loop through each line in a text file using a windows batch file?

The accepted anwser using cmd.exe and

for /F "tokens=*" %F in (file.txt) do whatever "%F" ...

works only for "normal" files. It fails miserably with huge files.

For big files, you may need to use Powershell and something like this:

[IO.File]::ReadLines("file.txt") | ForEach-Object { whatever "$_" }

or if you have enough memory:

foreach($line in [System.IO.File]::ReadLines("file.txt")) { whatever "$line" } 

This worked for me with a 250 MB file containing over 2 million lines, where the for /F ... command got stuck after a few thousand lines.

For the differences between foreach and ForEach-Object, see Getting to Know ForEach and ForEach-Object.

(credits: Read file line by line in PowerShell )

Get timezone from DateTime

You could use TimeZoneInfo class

The TimeZone class recognizes local time zone, and can convert times between Coordinated Universal Time (UTC) and local time. A TimeZoneInfo object can represent any time zone, and methods of the TimeZoneInfo class can be used to convert the time in one time zone to the corresponding time in any other time zone. The members of the TimeZoneInfo class support the following operations:

  1. Retrieving a time zone that is already defined by the operating system.

  2. Enumerating the time zones that are available on a system.

  3. Converting times between different time zones.

  4. Creating a new time zone that is not already defined by the operating system.

    Serializing a time zone for later retrieval.

How do I compare two variables containing strings in JavaScript?

You can use javascript dedicate string compare method string1.localeCompare(string2). it will five you -1 if the string not equals, 0 for strings equal and 1 if string1 is sorted after string2.

<script>
    var to_check=$(this).val();
    var cur_string=$("#0").text();
    var to_chk = "that";
    var cur_str= "that";
    if(to_chk.localeCompare(cur_str) == 0){
        alert("both are equal");
        $("#0").attr("class","correct");    
    } else {
        alert("both are not equal");
        $("#0").attr("class","incorrect");
    }
</script>

How to Get Element By Class in JavaScript?

I think something like:

function ReplaceContentInContainer(klass,content) {
var elems = document.getElementsByTagName('*');
for (i in elems){
    if(elems[i].getAttribute('class') == klass || elems[i].getAttribute('className') == klass){
        elems[i].innerHTML = content;
    }
}
}

would work

How do you create a read-only user in PostgreSQL?

By default new users will have permission to create tables. If you are planning to create a read-only user, this is probably not what you want.

To create a true read-only user with PostgreSQL 9.0+, run the following steps:

# This will prevent default users from creating tables
REVOKE CREATE ON SCHEMA public FROM public;

# If you want to grant a write user permission to create tables
# note that superusers will always be able to create tables anyway
GRANT CREATE ON SCHEMA public to writeuser;

# Now create the read-only user
CREATE ROLE readonlyuser WITH LOGIN ENCRYPTED PASSWORD 'strongpassword';
GRANT SELECT ON ALL TABLES IN SCHEMA public TO readonlyuser;

If your read-only user doesn't have permission to list tables (i.e. \d returns no results), it's probably because you don't have USAGE permissions for the schema. USAGE is a permission that allows users to actually use the permissions they have been assigned. What's the point of this? I'm not sure. To fix:

# You can either grant USAGE to everyone
GRANT USAGE ON SCHEMA public TO public;

# Or grant it just to your read only user
GRANT USAGE ON SCHEMA public TO readonlyuser;

Changing text of UIButton programmatically swift

Changing title when attributed is a bit different :

I just ran into a problem : If you have an UIButton with an Attributed Title, you have to use :

my_btn.setAttributedTitle(NSAttributedString(string: my_title), for: my_state)

as, per Apple SetTitle Doc :

If you set both a title and an attributed title for the button, the button prefers the use of the attributed title over this one.

I had an attributed title and I tried to setTitle on it, with no effect...

SQLSTATE[HY093]: Invalid parameter number: number of bound variables does not match number of tokens on line 102

You didn't bind all your bindings here

$sql = "SELECT SQL_CALC_FOUND_ROWS *, UNIX_TIMESTAMP(publicationDate) AS publicationDate     FROM comments WHERE articleid = :art 
ORDER BY " . mysqli_escape_string($order) . " LIMIT :numRows";

$st = $conn->prepare( $sql );
$st->bindValue( ":art", $art, PDO::PARAM_INT );

You've declared a binding called :numRows but you never actually bind anything to it.

UPDATE 2019: I keep getting upvotes on this and that reminded me of another suggestion

Double quotes are string interpolation in PHP, so if you're going to use variables in a double quotes string, it's pointless to use the concat operator. On the flip side, single quotes are not string interpolation, so if you've only got like one variable at the end of a string it can make sense, or just use it for the whole string.

In fact, there's a micro op available here since the interpreter doesn't care about parsing the string for variables. The boost is nearly unnoticable and totally ignorable on a small scale. However, in a very large application, especially good old legacy monoliths, there can be a noticeable performance increase if strings are used like this. (and IMO, it's easier to read anyway)

AngularJS : When to use service instead of factory

Explanation

You got different things here:

First:

  • If you use a service you will get the instance of a function ("this" keyword).
  • If you use a factory you will get the value that is returned by invoking the function reference (the return statement in factory).

ref: angular.service vs angular.factory

Second:

Keep in mind all providers in AngularJS (value, constant, services, factories) are singletons!

Third:

Using one or the other (service or factory) is about code style. But, the common way in AngularJS is to use factory.

Why ?

Because "The factory method is the most common way of getting objects into AngularJS dependency injection system. It is very flexible and can contain sophisticated creation logic. Since factories are regular functions, we can also take advantage of a new lexical scope to simulate "private" variables. This is very useful as we can hide implementation details of a given service."

(ref: http://www.amazon.com/Mastering-Web-Application-Development-AngularJS/dp/1782161821).


Usage

Service : Could be useful for sharing utility functions that are useful to invoke by simply appending () to the injected function reference. Could also be run with injectedArg.call(this) or similar.

Factory : Could be useful for returning a ‘class’ function that can then be new`ed to create instances.

So, use a factory when you have complex logic in your service and you don't want expose this complexity.

In other cases if you want to return an instance of a service just use service.

But you'll see with time that you'll use factory in 80% of cases I think.

For more details: http://blog.manishchhabra.com/2013/09/angularjs-service-vs-factory-with-example/


UPDATE :

Excellent post here : http://iffycan.blogspot.com.ar/2013/05/angular-service-or-factory.html

"If you want your function to be called like a normal function, use factory. If you want your function to be instantiated with the new operator, use service. If you don't know the difference, use factory."


UPDATE :

AngularJS team does his work and give an explanation: http://docs.angularjs.org/guide/providers

And from this page :

"Factory and Service are the most commonly used recipes. The only difference between them is that Service recipe works better for objects of custom type, while Factory can produce JavaScript primitives and functions."

Caused By: java.lang.NoClassDefFoundError: org/apache/log4j/Logger

You can use the following maven dependency in your pom file. Otherwise, you can download the following two jars from net and add it to your build path.

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-api</artifactId>
    <version>1.6.4</version>
</dependency>

<dependency>
    <groupId>org.slf4j</groupId>
    <artifactId>slf4j-log4j12</artifactId>
    <version>1.6.4</version>
</dependency>

This is copied from my working project. First make sure it is working in your project. Then you can change the versions to use any other(versions) compatible jars.

For AggCat, you can refer the POM file of the sample java application.

https://github.com/IntuitDeveloperRelations/IPP_Sample_Code/blob/master/CustomerAccountData/Java/AggCatSampleApplication/pom.xml

Thanks

ImportError: No module named scipy

if you are using pycharm go to settings and in project interpreter sub-tab click on "+" sign next to list and in the search bar in there search name "scipy" and install the package.

scipy

Delete duplicate records from a SQL table without a primary key

Having a database table without Primary Key is really and will say extremely BAD PRACTICE...so after you add one (ALTER TABLE)

Run this until you don't see any more duplicated records (that is the purpose of HAVING COUNT)

DELETE FROM [TABLE_NAME] WHERE [Id] IN 
(
    SELECT MAX([Id])
    FROM [TABLE_NAME]
    GROUP BY [TARGET_COLUMN]
    HAVING COUNT(*) > 1
)


SELECT MAX([Id]),[TABLE_NAME], COUNT(*) AS dupeCount
FROM [TABLE_NAME]
GROUP BY [TABLE_NAME]
HAVING COUNT(*) > 1

MAX([Id]) will cause to delete latest records (ones added after first created) in case you want the opposite meaning that in case of requiring deleting first records and leave the last record inserted please use MIN([Id])

MSSQL Select statement with incremental integer column... not from a table

Try ROW_NUMBER()

http://msdn.microsoft.com/en-us/library/ms186734.aspx

Example:

SELECT
  col1,
  col2,
  ROW_NUMBER() OVER (ORDER BY col1) AS rownum
FROM tbl

Data truncated for column?

In my case it was a table with an ENUM that accepts the days of the week as integers (0 to 6). When inserting the value 0 as an integer I got the error message "Data truncated for column ..." so to fix it I had to cast the integer to a string. So instead of:

$item->day = 0;

I had to do;

$item->day = (string) 0;

It looks silly to cast the zero like that but in my case it was in a Laravel factory, and I had to write it like this:

$factory->define(App\Schedule::class, function (Faker $faker) {
    return [
        'day' => (string) $faker->numberBetween(0, 6),
        //
    ];
});

How to get complete month name from DateTime

It's

DateTime.Now.ToString("MMMM");

With 4 Ms.

What exactly does the Access-Control-Allow-Credentials header do?

By default, CORS does not include cookies on cross-origin requests. This is different from other cross-origin techniques such as JSON-P. JSON-P always includes cookies with the request, and this behavior can lead to a class of vulnerabilities called cross-site request forgery, or CSRF.

In order to reduce the chance of CSRF vulnerabilities in CORS, CORS requires both the server and the client to acknowledge that it is ok to include cookies on requests. Doing this makes cookies an active decision, rather than something that happens passively without any control.

The client code must set the withCredentials property on the XMLHttpRequest to true in order to give permission.

However, this header alone is not enough. The server must respond with the Access-Control-Allow-Credentials header. Responding with this header to true means that the server allows cookies (or other user credentials) to be included on cross-origin requests.

You also need to make sure your browser isn't blocking third-party cookies if you want cross-origin credentialed requests to work.

Note that regardless of whether you are making same-origin or cross-origin requests, you need to protect your site from CSRF (especially if your request includes cookies).

How to access random item in list?

  1. Create an instance of Random class somewhere. Note that it's pretty important not to create a new instance each time you need a random number. You should reuse the old instance to achieve uniformity in the generated numbers. You can have a static field somewhere (be careful about thread safety issues):

    static Random rnd = new Random();
    
  2. Ask the Random instance to give you a random number with the maximum of the number of items in the ArrayList:

    int r = rnd.Next(list.Count);
    
  3. Display the string:

    MessageBox.Show((string)list[r]);
    

Split string based on regex

I suggest

l = re.compile("(?<!^)\s+(?=[A-Z])(?!.\s)").split(s)

Check this demo.

Unable to start MySQL server

See this post https://bugs.mysql.com/bug.php?id=67917 Sometimes a temp directory is missing. I had the same error like "InnoDB: Error: unable to create temporary file; errno: 2"

/exclude in xcopy just for a file type

In my case I had to start a list of exclude extensions from the second line because xcopy ignored the first line.

How can I get the iOS 7 default blue color programmatically?

iOS 7 default blue color is R:0.0 G:122.0 B:255.0

UIColor *ios7BlueColor = [UIColor colorWithRed:0.0 green:122.0/255.0 blue:1.0 alpha:1.0];

Laravel 5 route not defined, while it is?

when you execute the command

php artisan route:list

You will see all your registered routes in there in table format . Well there you see many columns like Method , URI , Name , Action .. etc.

So basically if you are using route() method that means it will accept only name column values and if you want to use URI column values you should go with url() method of laravel.

Why is HttpClient BaseAddress not working?

Ran into a issue with the HTTPClient, even with the suggestions still could not get it to authenticate. Turns out I needed a trailing '/' in my relative path.

i.e.

var result = await _client.GetStringAsync(_awxUrl + "api/v2/inventories/?name=" + inventoryName);
var result = await _client.PostAsJsonAsync(_awxUrl + "api/v2/job_templates/" + templateId+"/launch/" , new {
                inventory = inventoryId
            });

How to position a div in the middle of the screen when the page is bigger than the screen

Short answer, Just add position:fixed and that will solve your problem

Failed to load resource under Chrome

FYI - I had this issue as well and it turned out that my html listed the .jpg file with a .JPG in caps, but the file itself was lowercase .jpg. That rendered fine locally and using Codekit, but when it was pushed to the web it wouldn't load. Simply changing the file names to have a lowercase .jpg extension to match the html did the trick.

facet label font size

This should get you started:

R> qplot(hwy, cty, data = mpg) + 
       facet_grid(. ~ manufacturer) + 
       theme(strip.text.x = element_text(size = 8, colour = "orange", angle = 90))

See also this question: How can I manipulate the strip text of facet plots in ggplot2?

jQuery toggle CSS?

You can do by maintaining the state as below:

$('#user_button').on('click',function(){
    if($(this).attr('data-click-state') == 1) {
        $(this).attr('data-click-state', 0);
        $(this).css('background-color', 'red')
      }
    else {
      $(this).attr('data-click-state', 1);
      $(this).css('background-color', 'orange')
    }
  });

Take a reference from hear codepen example

MySQL Creating tables with Foreign Keys giving errno: 150

Please make sure at first that

  1. you are using InnoDB tables.
  2. field for FOREIGN KEY has the same type and length (!) as source field.

I had the same trouble and I've fixed it. I had unsigned INT for one field and just integer for other field.

CodeIgniter removing index.php from url

try this one.It may help you as its working for me.

RewriteEngine on
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule .* index.php/$0 [PT,L]

put the code in your root htaccess file.and make sure that you have

$config['index_page'] = '';

in your config file.

Please let me know if you face any problem.

php convert datetime to UTC

Use strtotime to generate a timestamp from the given string (interpreted as local time) and use gmdate to get it as a formatted UTC date back.

Example

As requested, here’s a simple example:

echo gmdate('d.m.Y H:i', strtotime('2012-06-28 23:55'));

How to set image in circle in swift

This way is the least expensive way and always keeps your image view rounded:

class RoundedImageView: UIImageView {

    override init(frame: CGRect) {
        super.init(frame: frame)

        clipsToBounds = true
    }

    required init?(coder aDecoder: NSCoder) {
        super.init(coder: aDecoder)

        clipsToBounds = true
    }

    override func layoutSubviews() {
        super.layoutSubviews()

        assert(bounds.height == bounds.width, "The aspect ratio isn't 1/1. You can never round this image view!")

        layer.cornerRadius = bounds.height / 2
    }
}

The other answers are telling you to make views rounded based on frame calculations set in a UIViewControllers viewDidLoad() method. This isn't correct, since it isn't sure what the final frame will be.

Setting a property with an EventTrigger

As much as I love XAML, for this kinds of tasks I switch to code behind. Attached behaviors are a good pattern for this. Keep in mind, Expression Blend 3 provides a standard way to program and use behaviors. There are a few existing ones on the Expression Community Site.

SQL query to get the deadlocks in SQL SERVER 2008

In order to capture deadlock graphs without using a trace (you don't need profiler necessarily), you can enable trace flag 1222. This will write deadlock information to the error log. However, the error log is textual, so you won't get nice deadlock graph pictures - you'll have to read the text of the deadlocks to figure it out.

I would set this as a startup trace flag (in which case you'll need to restart the service). However, you can run it only for the current running instance of the service (which won't require a restart, but which won't resume upon the next restart) using the following global trace flag command:

DBCC TRACEON(1222, -1);

A quick search yielded this tutorial:

http://www.mssqltips.com/sqlservertip/2130/finding-sql-server-deadlocks-using-trace-flag-1222/

Also note that if your system experiences a lot of deadlocks, this can really hammer your error log, and can become quite a lot of noise, drowning out other, important errors.

Have you considered third party monitoring tools? SQL Sentry Performance Advisor, for example, has a much nicer deadlock graph, showing you object / index names as well as the order in which the locks were taken. As a bonus, these are captured for you automatically on monitored servers without having to configure trace flags, run your own traces, etc.:

enter image description here

Disclaimer: I work for SQL Sentry.

How to override the [] operator in Python?

You need to use the __getitem__ method.

class MyClass:
    def __getitem__(self, key):
        return key * 2

myobj = MyClass()
myobj[3] #Output: 6

And if you're going to be setting values you'll need to implement the __setitem__ method too, otherwise this will happen:

>>> myobj[5] = 1
Traceback (most recent call last):
  File "<stdin>", line 1, in <module>
AttributeError: MyClass instance has no attribute '__setitem__'

Streaming Audio from A URL in Android using MediaPlayer?

No call mp.start with an OnPreparedListener to avoid the zero state i the log..

How does one create an InputStream from a String?

Beginning with Java 7, you can use the following idiom:

String someString = "...";
InputStream is = new ByteArrayInputStream( someString.getBytes(StandardCharsets.UTF_8) );

Variables as commands in bash scripts

Simply don't put whole commands in variables. You'll get into a lot of trouble trying to recover quoted arguments.

Also:

  1. Avoid using all-capitals variable names in scripts. Easy way to shoot yourself on the foot.
  2. Don't use backquotes, use $(...) instead, it nests better.

#! /bin/bash

if [ $# -ne 2 ]
then
    echo "Usage: $(basename $0) DIRECTORY BACKUP_DIRECTORY"
    exit 1
fi

directory=$1
backup_directory=$2
current_date=$(date +%Y-%m-%dT%H-%M-%S)
backup_file="${backup_directory}/${current_date}.backup"

tar cv "$directory" | openssl des3 -salt | split -b 1024m - "$backup_file"

javascript date to string

Maybe it is easier to convert the Date into the actual integer 20110506105524 and then convert this into a string:

function printDate() {
    var temp = new Date();
    var dateInt =
        ((((temp.getFullYear() * 100 + 
            temp.getMonth() + 1) * 100 + 
           temp.getDate()) * 100 +
          temp.getHours()) * 100 + 
         temp.getMinutes()) * 100 + 
        temp.getSeconds();

    debug ( '' + dateInt );  // convert to String
}

When temp.getFullYear() < 1000 the result will be one (or more) digits shorter.

Caution: this wont work with millisecond precision (i.e. 17 digits) since Number.MAX_SAFE_INTEGER is 9007199254740991 which is only 16 digits.

.NET End vs Form.Close() vs Application.Exit Cleaner way to close one's app

Application.Exit() kills your application but there are some instances that it won't close the application.

End is better than Application.Exit().

How to update and order by using ms sql

WITH    q AS
        (
        SELECT  TOP 10 *
        FROM    messages
        WHERE   status = 0
        ORDER BY
                priority DESC
        )
UPDATE  q
SET     status = 10

SQL - Rounding off to 2 decimal places

As an add-on to the answers below, when using INT or non-decimal datatypes in your formulas, remember to multiply the value by 1 and the number of decimals you prefer.

i.e. - TotalPackages is an INT and so the denominator TotalContainers, but I want my result to have up to 6 decimal places.

thus:

((m.TotalPackages * 1.000000) / m.TotalContainers) AS Packages,

Get Image Height and Width as integer values?

getimagesize('image.jpg') function works only if allow_url_fopen is set to 1 or On inside php.ini file on the server, if it is not enabled, one should use ini_set('allow_url_fopen',1); on top of the file where getimagesize() function is used.

Use of "this" keyword in C++

Yes, it is not required and is usually omitted. It might be required for accessing variables after they have been overridden in the scope though:

Person::Person() {
    int age;
    this->age = 1;
}

Also, this:

Person::Person(int _age) {
    age = _age;
}

It is pretty bad style; if you need an initializer with the same name use this notation:

Person::Person(int age) : age(age) {}

More info here: https://en.cppreference.com/w/cpp/language/initializer_list

In SSRS, why do I get the error "item with same key has already been added" , when I'm making a new report?

I had the same error in a report query. I had columns from different tables with the same name and the prefix for each table (eg: select a.description, b.description, c.description) that runs ok in Oracle, but for the report you must have an unique alias for each column so simply add alias to the fields with the same name (select a.description a_description, b.description b_description and so on)

Send JSON data via POST (ajax) and receive json response from Controller (MVC)

var SendInfo= { SendInfo: [... your elements ...]};

        $.ajax({
            type: 'post',
            url: 'Your-URI',
            data: JSON.stringify(SendInfo),
            contentType: "application/json; charset=utf-8",
            traditional: true,
            success: function (data) {
                ...
            }
        });

and in action

public ActionResult AddDomain(IEnumerable<PersonSheets> SendInfo){
...

you can bind your array like this

var SendInfo = [];

$(this).parents('table').find('input:checked').each(function () {
    var domain = {
        name: $("#id-manuf-name").val(),
        address: $("#id-manuf-address").val(),
        phone: $("#id-manuf-phone").val(),
    }

    SendInfo.push(domain);
});

hope this can help you.

how to access the command line for xampp on windows

In the version 3.2.4 of the XAMPP Control Panel, there is button that can open a command line prompt (red rectangle in the next figure)

enter image description here

After pressing the button, you will see the command prompt window.

enter image description here

From this window you can navigate through the different folders and start the different services available.

How do you add Boost libraries in CMakeLists.txt?

Adapting @LainIwakura's answer for modern CMake syntax with imported targets, this would be:

set(Boost_USE_STATIC_LIBS OFF) 
set(Boost_USE_MULTITHREADED ON)  
set(Boost_USE_STATIC_RUNTIME OFF) 
find_package(Boost 1.45.0 COMPONENTS filesystem regex) 

if(Boost_FOUND)
    add_executable(progname file1.cxx file2.cxx) 
    target_link_libraries(progname Boost::filesystem Boost::regex)
endif()

Note that it is not necessary anymore to specify the include directories manually, since it is already taken care of through the imported targets Boost::filesystem and Boost::regex.
regex and filesystem can be replaced by any boost libraries you need.

How to get rid of `deprecated conversion from string constant to ‘char*’` warnings in GCC?

I had a similar problem, I solved it like this:

#include <string.h>

extern void foo(char* m);

int main() {
    // warning: deprecated conversion from string constant to ‘char*’
    //foo("Hello");

    // no more warning
    char msg[] = "Hello";
    foo(msg);
}

Is this an appropriate way of solving this? I do not have access to foo to adapt it to accept const char*, although that would be a better solution (because foo does not change m).

Sum function in VBA

Function is not a property/method from range.

If you want to sum values then use the following:

Range("A1").Value = Application.Sum(Range(Cells(2, 1), Cells(3, 2)))

EDIT:

if you want the formula then use as follows:

Range("A1").Formula = "=SUM(" & Range(Cells(2, 1), Cells(3, 2)).Address(False, False) & ")"

'The two false after Adress is to define the address as relative (A2:B3).
'If you omit the parenthesis clause or write True instead, you can set the address
'as absolute ($A$2:$B$3).

In case you are allways going to use the same range address then you can use as Rory sugested:

Range("A1").Formula ="=Sum(A2:B3)"

Python and JSON - TypeError list indices must be integers not str

First of all, you should be using json.loads, not json.dumps. loads converts JSON source text to a Python value, while dumps goes the other way.

After you fix that, based on the JSON snippet at the top of your question, readable_json will be a list, and so readable_json['firstName'] is meaningless. The correct way to get the 'firstName' field of every element of a list is to eliminate the playerstuff = readable_json['firstName'] line and change for i in playerstuff: to for i in readable_json:.

The way to check a HDFS directory's size?

% of used space on Hadoop cluster
sudo -u hdfs hadoop fs –df

Capacity under specific folder:
sudo -u hdfs hadoop fs -du -h /user

Laravel $q->where() between dates

@Tom : Instead of using 'now' or 'addWeek' if we provide date in following format, it does not give correct records

$projects = Project::whereBetween('recur_at', array(new DateTime('2015-10-16'), new DateTime('2015-10-23')))
->where('status', '<', 5)
->where('recur_cancelled', '=', 0)
->get();

it gives records having date form 2015-10-16 to less than 2015-10-23. If value of recur_at is 2015-10-23 00:00:00 then only it shows that record else if it is 2015-10-23 12:00:45 then it is not shown.

Encrypt Password in Configuration Files?

The big point, and the elephant in the room and all that, is that if your application can get hold of the password, then a hacker with access to the box can get hold of it too!

The only way somewhat around this, is that the application asks for the "master password" on the console using Standard Input, and then uses this to decrypt the passwords stored on file. Of course, this completely makes is impossible to have the application start up unattended along with the OS when it boots.

However, even with this level of annoyance, if a hacker manages to get root access (or even just access as the user running your application), he could dump the memory and find the password there.

The thing to ensure, is to not let the entire company have access to the production server (and thereby to the passwords), and make sure that it is impossible to crack this box!

How do I display an alert dialog on Android?

This is definitely help for you. Try this code: On click of a button, you can put one, two or three buttons with an alert dialog...

SingleButtton.setOnClickListener(new View.OnClickListener() {

    public void onClick(View arg0) {
        // Creating alert Dialog with one Button

        AlertDialog alertDialog = new AlertDialog.Builder(AlertDialogActivity.this).create();

        // Setting Dialog Title
        alertDialog.setTitle("Alert Dialog");

        // Setting Dialog Message
        alertDialog.setMessage("Welcome to Android Application");

        // Setting Icon to Dialog
        alertDialog.setIcon(R.drawable.tick);

        // Setting OK Button
        alertDialog.setButton("OK", new DialogInterface.OnClickListener() {

            public void onClick(DialogInterface dialog,int which)
            {
                // Write your code here to execute after dialog    closed
                Toast.makeText(getApplicationContext(),"You clicked on OK", Toast.LENGTH_SHORT).show();
            }
        });

        // Showing Alert Message
        alertDialog.show();
    }
});

btnAlertTwoBtns.setOnClickListener(new View.OnClickListener() {

    public void onClick(View arg0) {
        // Creating alert Dialog with two Buttons

        AlertDialog.Builder alertDialog = new AlertDialog.Builder(AlertDialogActivity.this);

        // Setting Dialog Title
        alertDialog.setTitle("Confirm Delete...");

        // Setting Dialog Message
        alertDialog.setMessage("Are you sure you want delete this?");

        // Setting Icon to Dialog
        alertDialog.setIcon(R.drawable.delete);

        // Setting Positive "Yes" Button
        alertDialog.setPositiveButton("YES",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog,int which) {
                        // Write your code here to execute after dialog
                        Toast.makeText(getApplicationContext(), "You clicked on YES", Toast.LENGTH_SHORT).show();
                    }
                });

        // Setting Negative "NO" Button
        alertDialog.setNegativeButton("NO",
                new DialogInterface.OnClickListener() {
                    public void onClick(DialogInterface dialog,    int which) {
                        // Write your code here to execute after dialog
                        Toast.makeText(getApplicationContext(), "You clicked on NO", Toast.LENGTH_SHORT).show();
                        dialog.cancel();
                    }
                });

        // Showing Alert Message
        alertDialog.show();
    }
});

btnAlertThreeBtns.setOnClickListener(new View.OnClickListener() {

    public void onClick(View arg0) {
        // Creating alert Dialog with three Buttons

        AlertDialog.Builder alertDialog = new AlertDialog.Builder(
                AlertDialogActivity.this);

        // Setting Dialog Title
        alertDialog.setTitle("Save File...");

        // Setting Dialog Message
        alertDialog.setMessage("Do you want to save this file?");

        // Setting Icon to Dialog
        alertDialog.setIcon(R.drawable.save);

        // Setting Positive Yes Button
        alertDialog.setPositiveButton("YES",
            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog,
                        int which) {
                    // User pressed Cancel button. Write Logic Here
                    Toast.makeText(getApplicationContext(),
                            "You clicked on YES",
                            Toast.LENGTH_SHORT).show();
                }
            });

        // Setting Negative No Button... Neutral means in between yes and cancel button
        alertDialog.setNeutralButton("NO",
            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog,
                        int which) {
                    // User pressed No button. Write Logic Here
                    Toast.makeText(getApplicationContext(),
                            "You clicked on NO", Toast.LENGTH_SHORT)
                            .show();
                }
            });

        // Setting Positive "Cancel" Button
        alertDialog.setNegativeButton("Cancel",
            new DialogInterface.OnClickListener() {

                public void onClick(DialogInterface dialog,
                        int which) {
                    // User pressed Cancel button. Write Logic Here
                    Toast.makeText(getApplicationContext(),
                            "You clicked on Cancel",
                            Toast.LENGTH_SHORT).show();
                }
            });
        // Showing Alert Message
        alertDialog.show();
    }
});

How to get the selected radio button’s value?

This is pure JavaScript, based on the answer by @Fontas but with safety code to return an empty string (and avoid a TypeError) if there isn't a selected radio button:

var genderSRadio = document.querySelector("input[name=genderS]:checked");
var genderSValue = genderSRadio ? genderSRadio.value : "";

The code breaks down like this:

  • Line 1: get a reference to the control that (a) is an <input> type, (b) has a name attribute of genderS, and (c) is checked.
  • Line 2: If there is such a control, return its value. If there isn't, return an empty string. The genderSRadio variable is truthy if Line 1 finds the control and null/falsey if it doesn't.

For JQuery, use @jbabey's answer, and note that if there isn't a selected radio button it will return undefined.

HttpServlet cannot be resolved to a type .... is this a bug in eclipse?

A simple solution for me was to go to Properties -> Java Build Path -> Order and Export, then check the Apache Tomcat library. This is assumes you've already set Tomcat as your deployment target and are still getting the error.

Declaring a python function with an array parameters and passing an array argument to the function call?

What you have is on the right track.

def dosomething( thelist ):
    for element in thelist:
        print element

dosomething( ['1','2','3'] )
alist = ['red','green','blue']
dosomething( alist )  

Produces the output:

1
2
3
red
green
blue

A couple of things to note given your comment above: unlike in C-family languages, you often don't need to bother with tracking the index while iterating over a list, unless the index itself is important. If you really do need the index, though, you can use enumerate(list) to get index,element pairs, rather than doing the x in range(len(thelist)) dance.

how can I copy a conditional formatting in Excel 2010 to other cells, which is based on a other cells content?

You can do this in the 'Conditional Formatting' tool in the Home tab of Excel 2010.

Assuming the existing rule is 'Use a formula to dtermine which cells to format':

Edit the existing rule, so that the 'Formula' refers to relative rows and columns (i.e. remove $s), and then in the 'Applies to' box, click the icon to make the sheet current and select the cells you want the formatting to apply to (absolute cell references are ok here), then go back to the tool panel and click Apply.

This will work assuming the relative offsets are appropriate throughout your desired apply-to range.

You can copy conditional formatting from one cell to another or a range using copy and paste-special with formatting only, assuming you do not mind copying the normal formats.

Nested ifelse statement

Try something like the following:

# some sample data
idnat <- sample(c("french","foreigner"),100,TRUE)
idbp <- rep(NA,100)
idbp[idnat=="french"] <- sample(c("mainland","overseas","colony"),sum(idnat=="french"),TRUE)

# recoding
out <- ifelse(idnat=="french" & !idbp %in% c("overseas","colony"), "mainland",
              ifelse(idbp %in% c("overseas","colony"),"overseas",
                     "foreigner"))
cbind(idnat,idbp,out) # check result

Your confusion comes from how SAS and R handle if-else constructions. In R, if and else are not vectorized, meaning they check whether a single condition is true (i.e., if("french"=="french") works) and cannot handle multiple logicals (i.e., if(c("french","foreigner")=="french") doesn't work) and R gives you the warning you're receiving.

By contrast, ifelse is vectorized, so it can take your vectors (aka input variables) and test the logical condition on each of their elements, like you're used to in SAS. An alternative way to wrap your head around this would be to build a loop using if and else statements (as you've started to do here) but the vectorized ifelse approach will be more efficient and involve generally less code.

Foreach loop in java for a custom object list

Using can also use Java 8 stream API and do the same thing in one line.

If you want to print any specific property then use this syntax:

ArrayList<Room> rooms = new ArrayList<>();
rooms.forEach(room -> System.out.println(room.getName()));

OR

ArrayList<Room> rooms = new ArrayList<>();
rooms.forEach(room -> {
    // here room is available
});

if you want to print all the properties of Java object then use this:

ArrayList<Room> rooms = new ArrayList<>();
rooms.forEach(System.out::println);

How do I convert strings in a Pandas data frame to a 'date' data type?

Essentially equivalent to @waitingkuo, but I would use to_datetime here (it seems a little cleaner, and offers some additional functionality e.g. dayfirst):

In [11]: df
Out[11]:
   a        time
0  1  2013-01-01
1  2  2013-01-02
2  3  2013-01-03

In [12]: pd.to_datetime(df['time'])
Out[12]:
0   2013-01-01 00:00:00
1   2013-01-02 00:00:00
2   2013-01-03 00:00:00
Name: time, dtype: datetime64[ns]

In [13]: df['time'] = pd.to_datetime(df['time'])

In [14]: df
Out[14]:
   a                time
0  1 2013-01-01 00:00:00
1  2 2013-01-02 00:00:00
2  3 2013-01-03 00:00:00

Handling ValueErrors
If you run into a situation where doing

df['time'] = pd.to_datetime(df['time'])

Throws a

ValueError: Unknown string format

That means you have invalid (non-coercible) values. If you are okay with having them converted to pd.NaT, you can add an errors='coerce' argument to to_datetime:

df['time'] = pd.to_datetime(df['time'], errors='coerce')

Find duplicate records in MySQL

The key is to rewrite this query so that it can be used as a subquery.

SELECT firstname, 
   lastname, 
   list.address 
FROM list
   INNER JOIN (SELECT address
               FROM   list
               GROUP  BY address
               HAVING COUNT(id) > 1) dup
           ON list.address = dup.address;

How can I remove a pytz timezone from a datetime object?

To remove a timezone (tzinfo) from a datetime object:

# dt_tz is a datetime.datetime object
dt = dt_tz.replace(tzinfo=None)

If you are using a library like arrow, then you can remove timezone by simply converting an arrow object to to a datetime object, then doing the same thing as the example above.

# <Arrow [2014-10-09T10:56:09.347444-07:00]>
arrowObj = arrow.get('2014-10-09T10:56:09.347444-07:00')

# datetime.datetime(2014, 10, 9, 10, 56, 9, 347444, tzinfo=tzoffset(None, -25200))
tmpDatetime = arrowObj.datetime

# datetime.datetime(2014, 10, 9, 10, 56, 9, 347444)
tmpDatetime = tmpDatetime.replace(tzinfo=None)

Why would you do this? One example is that mysql does not support timezones with its DATETIME type. So using ORM's like sqlalchemy will simply remove the timezone when you give it a datetime.datetime object to insert into the database. The solution is to convert your datetime.datetime object to UTC (so everything in your database is UTC since it can't specify timezone) then either insert it into the database (where the timezone is removed anyway) or remove it yourself. Also note that you cannot compare datetime.datetime objects where one is timezone aware and another is timezone naive.

##############################################################################
# MySQL example! where MySQL doesn't support timezones with its DATETIME type!
##############################################################################

arrowObj = arrow.get('2014-10-09T10:56:09.347444-07:00')

arrowDt = arrowObj.to("utc").datetime

# inserts datetime.datetime(2014, 10, 9, 17, 56, 9, 347444, tzinfo=tzutc())
insertIntoMysqlDatabase(arrowDt)

# returns datetime.datetime(2014, 10, 9, 17, 56, 9, 347444)
dbDatetimeNoTz = getFromMysqlDatabase()

# cannot compare timzeone aware and timezone naive
dbDatetimeNoTz == arrowDt # False, or TypeError on python versions before 3.3

# compare datetimes that are both aware or both naive work however
dbDatetimeNoTz == arrowDt.replace(tzinfo=None) # True

Java reading a file into an ArrayList?

To share some analysis info. With a simple test how long it takes to read ~1180 lines of values.

If you need to read the data very fast, use the good old BufferedReader FileReader example. It took me ~8ms

The Scanner is much slower. Took me ~138ms

The nice Java 8 Files.lines(...) is the slowest version. Took me ~388ms.

Assign output of a program to a variable using a MS batch file

You could use a batch macro for simple capturing of command outputs, a bit like the behaviour of the bash shell.

The usage of the macro is simple and looks like

%$set% VAR=application arg1 arg2

And it works even with pipes

%$set% allDrives="wmic logicaldisk get name /value | findstr "Name""

The macro uses the variable like an array and stores each line in a separate index.
In the sample of %$set% allDrives="wmic logicaldisk there will the following variables created:

allDrives.Len=5
allDrives.Max=4
allDrives[0]=Name=C:
allDrives[1]=Name=D:
allDrives[2]=Name=F:
allDrives[3]=Name=G:
allDrives[4]=Name=Z:
allDrives=<contains the complete text with line feeds>

To use it, it's not important to understand how the macro itself works.

The full example

@echo off
setlocal

call :initMacro

%$set% ipOutput="ipconfig"
call :ShowVariable ipOutput
echo First line is %ipOutput[0]%

echo( 
%$set% driveNames="wmic logicaldisk get name /value | findstr "Name""
call :ShowVariable driveNames

exit /b

:ShowVariable
setlocal EnableDelayedExpansion
for /L %%n in (0 1 !%~1.max!) do (
    echo %%n: !%~1[%%n]!
)
echo(
exit /b

:initMacro
if "!!"=="" (
    echo ERROR: Delayed Expansion must be disabled while defining macros
    (goto) 2>nul
    (goto) 2>nul
)
(set LF=^
%=empty=%
)
(set \n=^^^
%=empty=%
)

set $set=FOR /L %%N in (1 1 2) dO IF %%N==2 ( %\n%
    setlocal EnableDelayedExpansion                                 %\n%
    for /f "tokens=1,* delims== " %%1 in ("!argv!") do (            %\n%
        endlocal                                                    %\n%
        endlocal                                                    %\n%
        set "%%~1.Len=0"                                            %\n%
        set "%%~1="                                                 %\n%
        if "!!"=="" (                                               %\n%
            %= Used if delayed expansion is enabled =%              %\n%
                setlocal DisableDelayedExpansion                    %\n%
                for /F "delims=" %%O in ('"%%~2 | findstr /N ^^"') do ( %\n%
                if "!!" NEQ "" (                                    %\n%
                    endlocal                                        %\n%
                    )                                               %\n%
                setlocal DisableDelayedExpansion                    %\n%
                set "line=%%O"                                      %\n%
                setlocal EnableDelayedExpansion                     %\n%
                set pathExt=:                                       %\n%
                set path=;                                          %\n%
                set "line=!line:^=^^!"                              %\n%
                set "line=!line:"=q"^""!"                           %\n%
                call set "line=%%line:^!=q""^!%%"                   %\n%
                set "line=!line:q""=^!"                             %\n%
                set "line="!line:*:=!""                             %\n%
                for /F %%C in ("!%%~1.Len!") do (                   %\n%
                    FOR /F "delims=" %%L in ("!line!") Do (         %\n%
                        endlocal                                    %\n%
                        endlocal                                    %\n%
                        set "%%~1[%%C]=%%~L" !                      %\n%
                        if %%C == 0 (                               %\n%
                            set "%%~1=%%~L" !                       %\n%
                        ) ELSE (                                    %\n%
                            set "%%~1=!%%~1!!LF!%%~L" !             %\n%
                        )                                           %\n%
                    )                                               %\n%
                    set /a %%~1.Len+=1                              %\n%
                )                                                   %\n%
            )                                                       %\n%
        ) ELSE (                                                    %\n%
            %= Used if delayed expansion is disabled =%             %\n%
            for /F "delims=" %%O in ('"%%~2 | findstr /N ^^"') do ( %\n%
                setlocal DisableDelayedExpansion                    %\n%
                set "line=%%O"                                      %\n%
                setlocal EnableDelayedExpansion                     %\n%
                set "line="!line:*:=!""                             %\n%
                for /F %%C in ("!%%~1.Len!") DO (                   %\n%
                    FOR /F "delims=" %%L in ("!line!") DO (         %\n%
                        endlocal                                    %\n%
                        endlocal                                    %\n%
                        set "%%~1[%%C]=%%~L"                        %\n%
                    )                                               %\n%
                    set /a %%~1.Len+=1                              %\n%
                )                                                   %\n%
            )                                                       %\n%
        )                                                           %\n%
        set /a %%~1.Max=%%~1.Len-1                                  %\n%
)                                                                   %\n%
    ) else setlocal DisableDelayedExpansion^&set argv=

goto :eof

How to get input from user at runtime

That is because you have used following line to assign the value which is wrong.

x=&x;

In PL/SQL assignment is done using following.

:=

So your code should be like this.

    declare
    x number;
    begin
    x:=&x;
-- Below line will output the number you received as an input
    dbms_output.put_line(x);
    end;
    /

How to find specified name and its value in JSON-string from Java?

I agree that Google's Gson is clear and easy to use. But you should create a result class for getting an instance from JSON string. If you can't clarify the result class, use json-simple:

// import static org.hamcrest.CoreMatchers.is;
// import static org.junit.Assert.assertThat;
// import org.json.simple.JSONObject;
// import org.json.simple.JSONValue;
// import org.junit.Test;

@Test
public void json2Object() {
    // given
    String jsonString = "{\"name\" : \"John\",\"age\" : \"20\","
            + "\"address\" : \"some address\","
            + "\"someobject\" : {\"field\" : \"value\"}}";

    // when
    JSONObject object = (JSONObject) JSONValue.parse(jsonString);

    // then
    @SuppressWarnings("unchecked")
    Set<String> keySet = object.keySet();
    for (String key : keySet) {
        Object value = object.get(key);
        System.out.printf("%s=%s (%s)\n", key, value, value.getClass()
                .getSimpleName());
    }

    assertThat(object.get("age").toString(), is("20"));
}

Pros and cons of Gson and json-simple is pretty much like pros and cons of user-defined Java Object and Map. The object you define is clear for all fields (name and type), but less flexible than Map.

What does "collect2: error: ld returned 1 exit status" mean?

clrscr is not standard C function. According to internet, it used to be a thing in old Borland C.
Is clrscr(); a function in C++?

Datatable select method ORDER BY clause

You can use the below simple method of sorting:

datatable.DefaultView.Sort = "Col2 ASC,Col3 ASC,Col4 ASC";

By the above method, you will be able to sort N number of columns.

JSONResult to String

You're looking for the JavaScriptSerializer class, which is used internally by JsonResult:

string json = new JavaScriptSerializer().Serialize(jsonResult.Data);

Apache HttpClient 4.0.3 - how do I set cookie with sessionID for POST request?

HttpContext localContext = new BasicHttpContext();
localContext.setAttribute(HttpClientContext.COOKIE_STORE, cookieStore);
response = client.execute(httppost, localContext);

doesn't work in 4.5 version without

cookie.setDomain(".domain.com");
cookie.setAttribute(ClientCookie.DOMAIN_ATTR, "true");

How to check if array is not empty?

I can't comment yet, but it should be mentioned that if you use numpy array with more than one element this will fail:

if l:
    print "list has items"

elif not l:
    print "list is empty"

the error will be:

ValueError: The truth value of an array with more than one element is ambiguous. Use a.any() or a.all()

How to change package name in flutter?

You can follow this official documentation by Google: https://developer.android.com/studio/build/application-id.html

Application ID should be changed in Build.gradle, while package name can be changed in AndroidManifest.xml.

However one should be careful changing package name.

Also while re uploading the app, one should be careful since it matches the application ID of previously uploaded app with new upload.

Remove border from IFrame

also set border="0px "

 <iframe src="yoururl" width="100%" height="100%" frameBorder="0"></iframe>

Spring Could not Resolve placeholder

You are not reading the properties file correctly. The propertySource should pass the parameter as: file:appclient.properties or classpath:appclient.properties. Change the annotation to:

@PropertySource(value={"classpath:appclient.properties"})

However I don't know what your PropertiesConfig file contains, as you're importing that also. Ideally the @PropertySource annotation should have been kept there.

Android Gradle Apache HttpClient does not exist?

Basically all you need to do is add:

useLibrary  'org.apache.http.legacy'

To your build.gradle file.

How to create a showdown.js markdown extension

In your last block you have a comma after 'lang', followed immediately with a function. This is not valid json.

EDIT

It appears that the readme was incorrect. I had to to pass an array with the string 'twitter'.

var converter = new Showdown.converter({extensions: ['twitter']}); converter.makeHtml('whatever @meandave2020'); // output "<p>whatever <a href="http://twitter.com/meandave2020">@meandave2020</a></p>" 

I submitted a pull request to update this.

Check if a value is within a range of numbers

If you must use a regexp (and really, you shouldn't!) this will work:

/^0\.00([1-8]\d*|90*)$/

should work, i.e.

  • ^ nothing before,
  • followed by 0.00 (nb: backslash escape for the . character)
  • followed by 1 through 8, and any number of additional digits
  • or 9, followed by any number of zeroes
  • $: followed by nothing else

How to specify test directory for mocha?

Run all files in test_directory including sub directories that match test.js

find ./parent_test_directory -name '*test.js' | xargs mocha -R spec

or use the --recursive switch

mocha --recursive test_directory/

What's the difference between size_t and int in C++?

It's because size_t can be anything other than an int (maybe a struct). The idea is that it decouples it's job from the underlying type.

BACKUP LOG cannot be performed because there is no current database backup

In our case it was due to the Recovery Model on the primary database having been changed after we did the backup in preparation for setting up log shipping.

Ensuring the Recovery Model was set to Full Recovery before doing the backup and setting up log shipping resolved it for us.

Checking if a list of objects contains a property with a specific value

using System.Linq;    
list.Where(x=> x.Name == nameToExtract);

Edit: misread question (now all matches)

How to fix Error: this class is not key value coding-compliant for the key tableView.'

Any chance that you changed the name of your table view from "tableView" to "myTableView" at some point?

How to switch Python versions in Terminal?

The simplest way would be to add an alias to python3 to always point to the native python installed. Add this line to the .bash_profile file in your $HOME directory at the last,

alias python="python3"

Doing so makes the changes to be reflected on every interactive shell opened.

How to compare files from two different branches?

I simply do git diff branch1 branch2 path/to/file

This checks for differences between the files. Changes in branch1 would be in red. Changes in branch2 would be in green.

It's assumed that branch1 is the past and branch2 is the future. You can reverse this by reversing the order of the branches in the diff: git diff branch2 branch1

How to insert special characters into a database?

$insert_data = mysql_real_escape_string($input_data);

Assuming that you have the data stored as $input_data

How to squash commits in git after they have been pushed?

1) git rebase -i HEAD~4

To elaborate: It works on the current branch; the HEAD~4 means squashing the latest four commits; interactive mode (-i)

2) At this point, the editor opened, with the list of commits, to change the second and following commits, replacing pick with squash then save it.

output: Successfully rebased and updated refs/heads/branch-name.

3) git push origin refs/heads/branch-name --force

output:

remote:
remote: To create a merge request for branch-name, visit:
remote: http://xxx/sc/server/merge_requests/new?merge_request%5Bsource_branch%5D=sss
remote:To ip:sc/server.git
 + 84b4b60...5045693 branch-name -> branch-name (forced update)

How to convert a UTF-8 string into Unicode?

What you have seems to be a string incorrectly decoded from another encoding, likely code page 1252, which is US Windows default. Here's how to reverse, assuming no other loss. One loss not immediately apparent is the non-breaking space (U+00A0) at the end of your string that is not displayed. Of course it would be better to read the data source correctly in the first place, but perhaps the data source was stored incorrectly to begin with.

using System;
using System.Text;

class Program
{
    static void Main(string[] args)
    {
        string junk = "déjÃ\xa0";  // Bad Unicode string

        // Turn string back to bytes using the original, incorrect encoding.
        byte[] bytes = Encoding.GetEncoding(1252).GetBytes(junk);

        // Use the correct encoding this time to convert back to a string.
        string good = Encoding.UTF8.GetString(bytes);
        Console.WriteLine(good);
    }
}

Result:

déjà

How to create a date object from string in javascript

I can't believe javascript isn't more consistent with parsing dates. And I hear the default when there is no timezone is gonna change from UTC to local -- hope the web is prepared ;)

I prefer to let Javascript do the heavy lifting when it comes to parsing dates. However it would be nice to handle the local timezone issue fairly transparently. With both of these things in mind, here is a function to do it with the current status quo -- and when Javascript changes it will still work but then can be removed (with a little time for people to catch up with older browsers/nodejs of course).

function strToDate(dateStr)
{
    var dateTry = new Date(dateStr);

    if (!dateTry.getTime())
    {
        throw new Exception("Bad Date! dateStr: " + dateStr);
    }

    var tz = dateStr.trim().match(/(Z)|([+-](\d{2})\:?(\d{2}))$/);

    if (!tz)
    {
        var newTzOffset = dateTry.getTimezoneOffset() / 60;
        var newSignStr = (newTzOffset >= 0) ? '-' : '+';
        var newTz = newSignStr + ('0' + Math.abs(newTzOffset)).slice(-2) + ':00';

        dateStr = dateStr.trim() + newTz;
        dateTry = new Date(dateStr);

        if (!dateTry.getTime())
        {
            throw new Exception("Bad Date! dateStr: " + dateStr);
        }
    }

    return dateTry;
}

We need a date object regardless; so createone. If there is a timezone, we are done. Otherwise, create a local timezone string using the +hh:mm format (more accepted than +hhmm).

Cookie blocked/not saved in IFRAME in Internet Explorer

A better solution would be to make an Ajax call inside the iframe to the page that would get/set cookies...

HttpContext.Current.Session is null when routing requests

I think this part of code make changes to the context.

 Page page = BuildManager.CreateInstanceFromVirtualPath(
                        m_VirtualPath, 
                        typeof(Page)) as Page;// IHttpHandler;

Also this part of code is useless:

 if (page != null)
 {
     return page;
 }
 return page;

It will always return the page wither it's null or not.

Decimal or numeric values in regular expression validation

Here is my regex for validating numbers:

^(-?[1-9]+\\d*([.]\\d+)?)$|^(-?0[.]\\d*[1-9]+)$|^0$

Valid numbers:

String []validNumbers={"3","-3","0","0.0","1.0","0.1","0.0001","-555","94549870965"};

Invalid numbers:

String []invalidNumbers={"a",""," ","-","001","-00.2","000.5",".3","3."," -1","--1","-.1","-0"};

Swift - How to detect orientation changes

Swift 4+: I was using this for soft keyboard design, and for some reason the UIDevice.current.orientation.isLandscape method kept telling me it was Portrait, so here's what I used instead:

override func viewWillTransition(to size: CGSize, with coordinator: UIViewControllerTransitionCoordinator) {
    super.viewWillTransition(to: size, with: coordinator)

    if(size.width > self.view.frame.size.width){
        //Landscape
    }
    else{
        //Portrait
    }
}

import sun.misc.BASE64Encoder results in error compiled in Eclipse

I am using unix system.

In eclipse project-> Properties -> Java Compiler -> Errors/Warning -> Forbidden Access(access rule) -> Turn it to warning/Ignore(Previously it was set to Error).

How can I stream webcam video with C#?

You could just use VideoLAN. VideoLAN will work as a server (or you can wrap your own C# application around it for more control). There are also .NET wrappers for the viewer that you can use and thus embed in your C# client.