Programs & Examples On #Brainbench

Brainbench provides online certifications mainly in the Information Technology field and others in general.

How to get values and keys from HashMap?

Map is internally made up of Map.Entry objects. Each Entry contains key and value. To get key and value from the entry you use accessor and modifier methods.

If you want to get values with given key, use get() method and to insert value, use put() method.

#Define and initialize map;
Map map = new HashMap();
map.put("USA",1)
map.put("Japan",3)
map.put("China",2)
map.put("India",5)
map.put("Germany",4)

map.get("Germany") // returns 4

If you want to get the set of keys from map, you can use keySet() method

Set keys = map.keySet();
System.out.println("All keys are: " + keys);
// To get all key: value
for(String key: keys){
    System.out.println(key + ": " + map.get(key));
}

Generally, To get all keys and values from the map, you have to follow the sequence in the following order:

  • Convert Hashmap to MapSet to get set of entries in Map with entryset() method.:
    Set st = map.entrySet();
  • Get the iterator of this set:
    Iterator it = st.iterator();
  • Get Map.Entry from the iterator:
    Map.Entry entry = it.next();
  • use getKey() and getValue() methods of the Map.Entry to get keys and values.
// Now access it
Set st = (Set) map.entrySet();
Iterator it = st.iterator();
while(it.hasNext()){
    Map.Entry entry = mapIterator.next();
    System.out.print(entry.getKey() + " : " + entry.getValue());
}

In short, use iterator directly in for

for(Map.Entry entry:map.entrySet()){
    System.out.print(entry.getKey() + " : " + entry.getValue());
}

org.springframework.beans.factory.NoSuchBeanDefinitionException: No bean named 'customerService' is defined

By reading your exception , It's sure that you forgot to autowire customerService

You should autowire your customerservice .

make following changes in your controller class

@Controller
public class CustomerController{

    @Autowired
    private Customerservice customerservice;
......other code......

}

Again your service implementation class

write

@Service
public class CustomerServiceImpl implements CustomerService {
    @Autowired
    private CustomerDAO customerDAO;
......other code......

.....add transactional methods
}

If you are using hibernate make necessary changes in your applicationcontext xml file(configuration of session factory is needed).

you should autowire sessionFactory set method in your DAO mplementation

please find samle application context :

<?xml  version="1.0" encoding="UTF-8"?>
<beans xmlns="http://www.springframework.org/schema/beans"
    xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
    xmlns:aop="http://www.springframework.org/schema/aop"
    xmlns:context="http://www.springframework.org/schema/context"
    xmlns:jee="http://www.springframework.org/schema/jee"
    xmlns:lang="http://www.springframework.org/schema/lang"
    xmlns:p="http://www.springframework.org/schema/p"
    xmlns:tx="http://www.springframework.org/schema/tx"
    xmlns:util="http://www.springframework.org/schema/util"
    xmlns:mvc="http://www.springframework.org/schema/mvc"
    xsi:schemaLocation="http://www.springframework.org/schema/beans http://www.springframework.org/schema/beans/spring-beans.xsd
        http://www.springframework.org/schema/aop http://www.springframework.org/schema/aop/spring-aop.xsd
        http://www.springframework.org/schema/context http://www.springframework.org/schema/context/spring-context.xsd
        http://www.springframework.org/schema/jee http://www.springframework.org/schema/jee/spring-jee.xsd
        http://www.springframework.org/schema/lang http://www.springframework.org/schema/lang/spring-lang.xsd
        http://www.springframework.org/schema/tx http://www.springframework.org/schema/tx/spring-tx.xsd
        http://www.springframework.org/schema/util http://www.springframework.org/schema/util/spring-util.xsd
        http://www.springframework.org/schema/mvc http://www.springframework.org/schema/mvc/spring-mvc.xsd">

    <context:annotation-config />
    <context:component-scan base-package="com.sparkle" />
    <!-- Configures the @Controller programming model -->
    <mvc:annotation-driven />

    <bean id="viewResolver" class="org.springframework.web.servlet.view.InternalResourceViewResolver" 
            p:prefix="/WEB-INF/jsp/" p:suffix=".jsp" p:order="0" />

    <bean id="messageSource"
        class="org.springframework.context.support.ReloadableResourceBundleMessageSource">
        <property name="basename" value="classpath:messages" />
        <property name="defaultEncoding" value="UTF-8" />
    </bean>
    <!-- <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer"
        p:location="/WEB-INF/jdbc.properties" /> -->

     <bean id="propertyConfigurer"
        class="org.springframework.beans.factory.config.PropertyPlaceholderConfigurer">
    <property name="locations">         
        <list>
            <value>/WEB-INF/jdbc.properties</value>          

        </list>    
    </property>     
    </bean>




    <bean id="dataSource"
        class="org.springframework.jdbc.datasource.DriverManagerDataSource"
        p:driverClassName="${jdbc.driverClassName}"
        p:url="${jdbc.databaseurl}" p:username="${jdbc.username}"
        p:password="${jdbc.password}" />


    <bean id="sessionFactory"
        class="org.springframework.orm.hibernate3.LocalSessionFactoryBean">
        <property name="dataSource" ref="dataSource" />
        <property name="configLocation">
            <value>classpath:hibernate.cfg.xml</value>
        </property>
        <property name="configurationClass">
            <value>org.hibernate.cfg.AnnotationConfiguration</value>
        </property>
        <property name="hibernateProperties">
            <props>
                <prop key="hibernate.dialect">${jdbc.dialect}</prop>
                <prop key="hibernate.show_sql">true</prop>
            </props>
        </property>
    </bean>

    <tx:annotation-driven />


   <bean id="transactionManager" class="org.springframework.orm.hibernate3.HibernateTransactionManager"
          p:sessionFactory-ref="sessionFactory"/>


</beans>

note that i am using jdbc.properties file for jdbc url and driver specification

Bootstrap datepicker disabling past dates without current date

var date = new Date();
date.setDate(date.getDate()-1);

$('#date').datepicker({ 
    startDate: date
});

Styling every 3rd item of a list using CSS?

You can use the :nth-child selector for that

li:nth-child(3n) {
 /* your rules here */
}

ENOENT, no such file or directory

__dirname 

Gives you the current node application's rooth directory.

In your case, you'd use

__dirname + '/Desktop/MyApp/newversion/partials/navigation.jade';

See this answer:

App base path from a module in NodeJS

How do I bind the enter key to a function in tkinter?

Another alternative is to use a lambda:

ent.bind("<Return>", (lambda event: name_of_function()))

Full code:

from tkinter import *
from tkinter.messagebox import showinfo

def reply(name):
    showinfo(title="Reply", message = "Hello %s!" % name)


top = Tk()
top.title("Echo")
top.iconbitmap("Iconshock-Folder-Gallery.ico")

Label(top, text="Enter your name:").pack(side=TOP)
ent = Entry(top)
ent.bind("<Return>", (lambda event: reply(ent.get())))
ent.pack(side=TOP)
btn = Button(top,text="Submit", command=(lambda: reply(ent.get())))
btn.pack(side=LEFT)

top.mainloop()

As you can see, creating a lambda function with an unused variable "event" solves the problem.

How do I create a URL shortener?

A Node.js and MongoDB solution

Since we know the format that MongoDB uses to create a new ObjectId with 12 bytes.

  • a 4-byte value representing the seconds since the Unix epoch,
  • a 3-byte machine identifier,
  • a 2-byte process id
  • a 3-byte counter (in your machine), starting with a random value.

Example (I choose a random sequence) a1b2c3d4e5f6g7h8i9j1k2l3

  • a1b2c3d4 represents the seconds since the Unix epoch,
  • 4e5f6g7 represents machine identifier,
  • h8i9 represents process id
  • j1k2l3 represents the counter, starting with a random value.

Since the counter will be unique if we are storing the data in the same machine we can get it with no doubts that it will be duplicate.

So the short URL will be the counter and here is a code snippet assuming that your server is running properly.

const mongoose = require('mongoose');
const Schema = mongoose.Schema;

// Create a schema
const shortUrl = new Schema({
    long_url: { type: String, required: true },
    short_url: { type: String, required: true, unique: true },
  });
const ShortUrl = mongoose.model('ShortUrl', shortUrl);

// The user can request to get a short URL by providing a long URL using a form

app.post('/shorten', function(req ,res){
    // Create a new shortUrl */
    // The submit form has an input with longURL as its name attribute.
    const longUrl = req.body["longURL"];
    const newUrl = ShortUrl({
        long_url : longUrl,
        short_url : "",
    });
    const shortUrl = newUrl._id.toString().slice(-6);
    newUrl.short_url = shortUrl;
    console.log(newUrl);
    newUrl.save(function(err){
        console.log("the new URL is added");
    })
});

Angular.js How to change an elements css class on click and to remove all others

Create a scope property called selectedIndex, and an itemClicked function:

function MyController ($scope) {
  $scope.collection = ["Item 1", "Item 2"];

  $scope.selectedIndex = 0; // Whatever the default selected index is, use -1 for no selection

  $scope.itemClicked = function ($index) {
    $scope.selectedIndex = $index;
  };
}

Then my template would look something like this:

<div>
      <span ng-repeat="item in collection"
             ng-class="{ 'selected-class-name': $index == selectedIndex }"
             ng-click="itemClicked($index)"> {{ item }} </span>
</div>

Just for reference $index is a magic variable available within ng-repeat directives.

You can use this same sample within a directive and template as well.

Here is a working plnkr:

http://plnkr.co/edit/jOO8YdPiSJEaOcayEP1X?p=preview

What is the difference between == and equals() in Java?

In short, the answer is "Yes".

In Java, the == operator compares the two objects to see if they point to the same memory location; while the .equals() method actually compares the two objects to see if they have the same object value.

How do I set a conditional breakpoint in gdb, when char* x points to a string whose value equals "hello"?

Since GDB 7.5 you can use these native Convenience Functions:

$_memeq(buf1, buf2, length)
$_regex(str, regex)
$_streq(str1, str2)
$_strlen(str)

Seems quite less problematic than having to execute a "foreign" strcmp() on the process' stack each time the breakpoint is hit. This is especially true for debugging multithreaded processes.

Note your GDB needs to be compiled with Python support, which is not an issue with current linux distros. To be sure, you can check it by running show configuration inside GDB and searching for --with-python. This little oneliner does the trick, too:

$ gdb -n -quiet -batch -ex 'show configuration' | grep 'with-python'
             --with-python=/usr (relocatable)

For your demo case, the usage would be

break <where> if $_streq(x, "hello")

or, if your breakpoint already exists and you just want to add the condition to it

condition <breakpoint number> $_streq(x, "hello")

$_streq only matches the whole string, so if you want something more cunning you should use $_regex, which supports the Python regular expression syntax.

Modify the legend of pandas bar plot

To change the labels for Pandas df.plot() use ax.legend([...]):

import pandas as pd
import matplotlib.pyplot as plt

fig, ax = plt.subplots()
df = pd.DataFrame({'A':26, 'B':20}, index=['N'])
df.plot(kind='bar', ax=ax)
#ax = df.plot(kind='bar') # "same" as above
ax.legend(["AAA", "BBB"]);

enter image description here

Another approach is to do the same by plt.legend([...]):

import matplotlib.pyplot as plt
df.plot(kind='bar')
plt.legend(["AAA", "BBB"]);

enter image description here

Invoke-WebRequest, POST with parameters

For some picky web services, the request needs to have the content type set to JSON and the body to be a JSON string. For example:

Invoke-WebRequest -UseBasicParsing http://example.com/service -ContentType "application/json" -Method POST -Body "{ 'ItemID':3661515, 'Name':'test'}"

or the equivalent for XML, etc.

How to start MySQL server on windows xp

The MySQL server can be started manually from the command line. This can be done on any version of Windows.

To start the mysqld server from the command line, you should start a console window (or “DOS window”) and enter this command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqld"
The path to mysqld may vary depending on the install location of MySQL on your system.

You can stop the MySQL server by executing this command:

shell> "C:\Program Files\MySQL\MySQL Server 5.0\bin\mysqladmin" -u root shutdown

**Note : **

If the MySQL root user account has a password, you need to invoke mysqladmin with the -p option and supply the password when prompted.

This command invokes the MySQL administrative utility mysqladmin to connect to the server and tell it to shut down. The command connects as the MySQL root user, which is the default administrative account in the MySQL grant system. Note that users in the MySQL grant system are wholly independent from any login users under Windows.

If mysqld doesn't start, check the error log to see whether the server wrote any messages there to indicate the cause of the problem. The error log is located in the C:\Program Files\MySQL\MySQL Server 5.0\data directory. It is the file with a suffix of .err. You can also try to start the server as mysqld --console; in this case, you may get some useful information on the screen that may help solve the problem.

The last option is to start mysqld with the --standalone and --debug options. In this case, mysqld writes a log file C:\mysqld.trace that should contain the reason why mysqld doesn't start. See MySQL Internals: Porting to Other Systems.

Via MySQL Official Page

Random record from MongoDB

Do a count of all records, generate a random number between 0 and the count, and then do:

db.yourCollection.find().limit(-1).skip(yourRandomNumber).next()

to call onChange event after pressing Enter key

pressing Enter when the focus in on a form control (input) normally triggers a submit (onSubmit) event on the form itself (not the input) so you could bind your this.handleInput to the form onSubmit.

Alternatively you could bind it to the blur (onBlur) event on the input which happens when the focus is removed (e.g. tabbing to the next element that can get focus)

SASS :not selector

I tried re-creating this, and .someclass.notip was being generated for me but .someclass:not(.notip) was not, for as long as I did not have the @mixin tip() defined. Once I had that, it all worked.

http://sassmeister.com/gist/9775949

$dropdown-width: 100px;
$comp-tip: true;

@mixin tip($pos:right) {

}

@mixin dropdown-pos($pos:right) {
  &:not(.notip) {
    @if $comp-tip == true{
      @if $pos == right {
        top:$dropdown-width * -0.6;
        background-color: #f00;
        @include tip($pos:$pos);
      }
    }
  }
  &.notip {
    @if $pos == right {
      top: 0;
      left:$dropdown-width * 0.8;
      background-color: #00f;
    }
  }
}

.someclass { @include dropdown-pos(); }

EDIT: http://sassmeister.com/ is a good place to debug your SASS because it gives you error messages. Undefined mixin 'tip'. it what I get when I remove @mixin tip($pos:right) { }

Parsing JSON array with PHP foreach

$user->data is an array of objects. Each element in the array has a name and value property (as well as others).

Try putting the 2nd foreach inside the 1st.

foreach($user->data as $mydata)
{
    echo $mydata->name . "\n";
    foreach($mydata->values as $values)
    {
        echo $values->value . "\n";
    }
}

IBOutlet and IBAction

Ran into the diagram while looking at key-value coding, thought it might help someone. It helps with understanding of what IBOutlet is.

By looking at the flow, one could see that IBOutlets are only there to match the property name with a control name in the Nib file.

How nib file is loaded, screenshot of Matt's online book for iOS6

What is this spring.jpa.open-in-view=true property in Spring Boot?

This property will register an OpenEntityManagerInViewInterceptor, which registers an EntityManager to the current thread, so you will have the same EntityManager until the web request is finished. It has nothing to do with a Hibernate SessionFactory etc.

Excel: replace part of cell's string value

I know this is old but I had a similar need for this and I did not want to do the find and replace version. It turns out that you can nest the substitute method like so:

=SUBSTITUTE(SUBSTITUTE(F149, "a", " AM"), "p", " PM")

In my case, I am using excel to view a DBF file and however it was populated has times like this:

9:16a
2:22p

So I just made a new column and put that formula in it to convert it to the excel time format.

Is there an advantage to use a Synchronized Method instead of a Synchronized Block?

Synchronized Method

Pros:

  • Your IDE can indicate the synchronized methods.
  • The syntax is more compact.
  • Forces to split the synchronized blocks to separate methods.

Cons:

  • Synchronizes to this and so makes it possible to outsiders to synchronize to it too.
  • It is harder to move code outside the synchronized block.

Synchronized block

Pros:

  • Allows using a private variable for the lock and so forcing the lock to stay inside the class.
  • Synchronized blocks can be found by searching references to the variable.

Cons:

  • The syntax is more complicated and so makes the code harder to read.

Personally I prefer using synchronized methods with classes focused only to the thing needing synchronization. Such class should be as small as possible and so it should be easy to review the synchronization. Others shouldn't need to care about synchronization.

SimpleDateFormat and locale based format string

Use DateFormat.getDateInstance(int style, Locale locale) instead of creating your own patterns with SimpleDateFormat.

Calculating distance between two geographic locations

    private static Double _MilesToKilometers = 1.609344;
    private static Double _MilesToNautical = 0.8684;


    /// <summary>
    /// Calculates the distance between two points of latitude and longitude.
    /// Great Link - http://www.movable-type.co.uk/scripts/latlong.html
    /// </summary>
    /// <param name="coordinate1">First coordinate.</param>
    /// <param name="coordinate2">Second coordinate.</param>
    /// <param name="unitsOfLength">Sets the return value unit of length.</param>
    public static Double Distance(Coordinate coordinate1, Coordinate coordinate2, UnitsOfLength unitsOfLength)
    {

        double theta = coordinate1.getLongitude() - coordinate2.getLongitude();
        double distance = Math.sin(ToRadian(coordinate1.getLatitude())) * Math.sin(ToRadian(coordinate2.getLatitude())) +
                       Math.cos(ToRadian(coordinate1.getLatitude())) * Math.cos(ToRadian(coordinate2.getLatitude())) *
                       Math.cos(ToRadian(theta));

        distance = Math.acos(distance);
        distance = ToDegree(distance);
        distance = distance * 60 * 1.1515;

        if (unitsOfLength == UnitsOfLength.Kilometer)
            distance = distance * _MilesToKilometers;
        else if (unitsOfLength == UnitsOfLength.NauticalMiles)
            distance = distance * _MilesToNautical;

        return (distance);

    }

How to delete specific columns with VBA?

You were just missing the second half of the column statement telling it to remove the entire column, since most normal Ranges start with a Column Letter, it was looking for a number and didn't get one. The ":" gets the whole column, or row.

I think what you were looking for in your Range was this:

Range("C:C,F:F,I:I,L:L,O:O,R:R").Delete

Just change the column letters to match your needs.

What does -XX:MaxPermSize do?

The permanent space is where the classes, methods, internalized strings, and similar objects used by the VM are stored and never deallocated (hence the name).

This Oracle article succinctly presents the working and parameterization of the HotSpot GC and advises you to augment this space if you load many classes (this is typically the case for application servers and some IDE like Eclipse) :

The permanent generation does not have a noticeable impact on garbage collector performance for most applications. However, some applications dynamically generate and load many classes; for example, some implementations of JavaServer Pages (JSP) pages. These applications may need a larger permanent generation to hold the additional classes. If so, the maximum permanent generation size can be increased with the command-line option -XX:MaxPermSize=.

Note that this other Oracle documentation lists the other HotSpot arguments.

Update : Starting with Java 8, both the permgen space and this setting are gone. The memory model used for loaded classes and methods is different and isn't limited (with default settings). You should not see this error any more.

Generate random numbers using C++11 random library

My 'random' library provide a high convenient wrapper around C++11 random classes. You can do almost all things with a simple 'get' method.

Examples:

  1. Random number in a range

    auto val = Random::get(-10, 10); // Integer
    auto val = Random::get(10.f, -10.f); // Float point
    
  2. Random boolean

    auto val = Random::get<bool>( ) // 50% to generate true
    auto val = Random::get<bool>( 0.7 ) // 70% to generate true
    
  3. Random value from a std::initilizer_list

    auto val = Random::get( { 1, 3, 5, 7, 9 } ); // val = 1 or 3 or...
    
  4. Random iterator from iterator range or all container

    auto it = Random::get( vec.begin(), vec.end() ); // it = random iterator
    auto it = Random::get( vec ); // return random iterator
    

And even more things ! Check out the github page:

https://github.com/effolkronium/random

Connection Java-MySql : Public Key Retrieval is not allowed

You should add client option to your mysql-connector allowPublicKeyRetrieval=true to allow the client to automatically request the public key from the server. Note that AllowPublicKeyRetrieval=True could allow a malicious proxy to perform a MITM attack to get the plaintext password, so it is False by default and must be explicitly enabled.

https://mysql-net.github.io/MySqlConnector/connection-options/

you could also try adding useSSL=false when you use it for testing/develop purposes

example:

jdbc:mysql://localhost:3306/db?allowPublicKeyRetrieval=true&useSSL=false

How to add onload event to a div element

No, you can't. The easiest way to make it work would be to put the function call directly after the element

Example:

...
<div id="somid">Some content</div>
<script type="text/javascript">
   oQuickReply.swap('somid');
</script>
...

or - even better - just in front of </body>:

...
<script type="text/javascript">
   oQuickReply.swap('somid');
</script>
</body>

...so it doesn't block the following content from loading.

is there a post render callback for Angular JS directive?

I had the same problem and I believe the answer really is no. See Miško's comment and some discussion in the group.

Angular can track that all of the function calls it makes to manipulate the DOM are complete, but since those functions could trigger async logic that's still updating the DOM after they return, Angular couldn't be expected to know about it. Any callback Angular gives might work sometimes, but wouldn't be safe to rely on.

We solved this heuristically with a setTimeout, as you did.

(Please keep in mind that not everyone agrees with me - you should read the comments on the links above and see what you think.)

Python: TypeError: cannot concatenate 'str' and 'int' objects

c = a + b 
str(c)

Actually, in this last line you are not changing the type of the variable c. If you do

c_str=str(c)
print "a + b as integers: " + c_str

it should work.

.crx file install in chrome

In case Chrome tells you "This can only be added from the Chrome Web Store", you can try the following:

  • Go to the webstore and try to add the extension
  • It will fail and give you a download instead
  • Rename the downloaded file to .zip and unpack it to a directory (you might get a warning about a corrupt zip header, but most unpacker will continue anyway)
  • Go to Settings -> Tools -> Extensions
  • Enable developer mode
  • Click "Load unpacked extention"
  • Browse to the unpacked folder and install your extention

update query with join on two tables

update addresses set cid=id where id in (select id from customers)

How to set the DefaultRoute to another Route in React Router

You use it like this to redirect on a particular URL and render component after redirecting from old-router to new-router.

<Route path="/old-router">
  <Redirect exact to="/new-router"/>
  <Route path="/new-router" component={NewRouterType}/>
</Route>

xpath find if node exists

I work in Ruby and using Nokogiri I fetch the element and look to see if the result is nil.

require 'nokogiri'

url = "http://somthing.com/resource"

resp = Nokogiri::XML(open(url))

first_name = resp.xpath("/movies/actors/actor[1]/first-name")

puts "first-name not found" if first_name.nil?

HTML embed autoplay="false", but still plays automatically

The problem is your plugin. To solve this is to only enter this address:

chrome://flags/#enable-NPAPI

Click activate NPAPI, and finally restart at the bottom of the page.

OnClick Send To Ajax

<textarea name='Status'> </textarea>
<input type='button' value='Status Update'>

You have few problems with your code like using . for concatenation

Try this -

$(function () {
    $('input').on('click', function () {
        var Status = $(this).val();
        $.ajax({
            url: 'Ajax/StatusUpdate.php',
            data: {
                text: $("textarea[name=Status]").val(),
                Status: Status
            },
            dataType : 'json'
        });
    });
});

Number of regex matches

#An example for counting matched groups
import re

pattern = re.compile(r'(\w+).(\d+).(\w+).(\w+)', re.IGNORECASE)
search_str = "My 11 Char String"

res = re.match(pattern, search_str)
print(len(res.groups())) # len = 4  
print (res.group(1) ) #My
print (res.group(2) ) #11
print (res.group(3) ) #Char
print (res.group(4) ) #String

What is a View in Oracle?

A View in Oracle and in other database systems is simply the representation of a SQL statement that is stored in memory so that it can easily be re-used. For example, if we frequently issue the following query

SELECT customerid, customername FROM customers WHERE countryid='US';

To create a view use the CREATE VIEW command as seen in this example

CREATE VIEW view_uscustomers
AS
SELECT customerid, customername FROM customers WHERE countryid='US';

This command creates a new view called view_uscustomers. Note that this command does not result in anything being actually stored in the database at all except for a data dictionary entry that defines this view. This means that every time you query this view, Oracle has to go out and execute the view and query the database data. We can query the view like this:

SELECT * FROM view_uscustomers WHERE customerid BETWEEN 100 AND 200;

And Oracle will transform the query into this:

SELECT * 
FROM (select customerid, customername from customers WHERE countryid='US') 
WHERE customerid BETWEEN 100 AND 200

Benefits of using Views

  • Commonality of code being used. Since a view is based on one common set of SQL, this means that when it is called it’s less likely to require parsing.
  • Security. Views have long been used to hide the tables that actually contain the data you are querying. Also, views can be used to restrict the columns that a given user has access to.
  • Predicate pushing

You can find advanced topics in this article about "How to Create and Manage Views in Oracle."

How to update MySql timestamp column to current timestamp on PHP?

Another option:

UPDATE `table` SET the_col = current_timestamp

Looks odd, but works as expected. If I had to guess, I'd wager this is slightly faster than calling now().

Is it possible to forward-declare a function in Python?

# declare a fake function (prototype) with no body
def foo(): pass

def bar():
    # use the prototype however you see fit
    print(foo(), "world!")

# define the actual function (overwriting the prototype)
def foo():
    return "Hello,"

bar()

Output:

Hello, world!

Largest and smallest number in an array

If you need to use foreach (for some reason) and don't want to use bult-in functions, here is a code snippet:

int minint = array[0];
int maxint = array[0];
foreach (int value in array) {
  if (value < minint) minint = value;
  if (value > maxint) maxint = value;
}

Get the index of a certain value in an array in PHP

Other folks have suggested array_search() which gives the key of the array element where the value is found. You can ensure that the array keys are contiguous integers by using array_values():

$list = array(0=>'string1', 'foo'=>'string2', 42=>'string3');
$index = array_search('string2', array_values($list));
print "$index\n";

// result: 1

You said in your question that array_search() was no use. Can you explain why? What did you try and how did it not meet your needs?

Get all rows from SQLite

Cursor cursor = myDb.viewData();

        if (cursor.moveToFirst()){
              do {
                 String itemname=cursor.getString(cursor.getColumnIndex(myDb.col_2));
                 String price=cursor.getString(cursor.getColumnIndex(myDb.col_3));
                 String quantity=cursor.getString(cursor.getColumnIndex(myDb.col_4));
                 String table_no=cursor.getString(cursor.getColumnIndex(myDb.col_5));

                 }while (cursor.moveToNext());

                }

                cursor.requery();

Editable text to string

This code work correctly only when u put into button click because at that time user put values into editable text and then when user clicks button it fetch the data and convert into string

EditText dob=(EditText)findviewbyid(R.id.edit_id);
String  str=dob.getText().toString();

Having links relative to root?

To give a URL to an image tag which locates images/ directory in the root like

`logo.png`

you should give src URL starting with / as follows:

<img src="/images/logo.png"/>

This code works in any directories without any troubles even if you are in branches/europe/about.php still the logo can be seen right there.

Check if string ends with certain pattern

You can test if a string ends with work followed by one character like this:

theString.matches(".*work.$");

If the trailing character is optional you can use this:

theString.matches(".*work.?$");

To make sure the last character is a period . or a slash / you can use this:

theString.matches(".*work[./]$");

To test for work followed by an optional period or slash you can use this:

theString.matches(".*work[./]?$");

To test for work surrounded by periods or slashes, you could do this:

theString.matches(".*[./]work[./]$");

If the tokens before and after work must match each other, you could do this:

theString.matches(".*([./])work\\1$");

Your exact requirement isn't precisely defined, but I think it would be something like this:

theString.matches(".*work[,./]?$");

In other words:

  • zero or more characters
  • followed by work
  • followed by zero or one , . OR /
  • followed by the end of the input

Explanation of various regex items:

.               --  any character
*               --  zero or more of the preceeding expression
$               --  the end of the line/input
?               --  zero or one of the preceeding expression
[./,]           --  either a period or a slash or a comma
[abc]           --  matches a, b, or c
[abc]*          --  zero or more of (a, b, or c)
[abc]?          --  zero or one of (a, b, or c)

enclosing a pattern in parentheses is called "grouping"

([abc])blah\\1  --  a, b, or c followed by blah followed by "the first group"

Here's a test harness to play with:

class TestStuff {

    public static void main (String[] args) {

        String[] testStrings = { 
                "work.",
                "work-",
                "workp",
                "/foo/work.",
                "/bar/work",
                "baz/work.",
                "baz.funk.work.",
                "funk.work",
                "jazz/junk/foo/work.",
                "funk/punk/work/",
                "/funk/foo/bar/work",
                "/funk/foo/bar/work/",
                ".funk.foo.bar.work.",
                ".funk.foo.bar.work",
                "goo/balls/work/",
                "goo/balls/work/funk"
        };

        for (String t : testStrings) {
            print("word: " + t + "  --->  " + matchesIt(t));
        }
    }

    public static boolean matchesIt(String s) {
        return s.matches(".*([./,])work\\1?$");
    }

    public static void print(Object o) {
        String s = (o == null) ? "null" : o.toString();
        System.out.println(o);
    }

}

How to write a SQL DELETE statement with a SELECT statement in the WHERE clause?

Your second DELETE query was nearly correct. Just be sure to put the table name (or an alias) between DELETE and FROM to specify which table you are deleting from. This is simpler than using a nested SELECT statement like in the other answers.

Corrected Query (option 1: using full table name):

DELETE tableA
FROM tableA
INNER JOIN tableB u on (u.qlabel = tableA.entityrole AND u.fieldnum = tableA.fieldnum) 
WHERE (LENGTH(tableA.memotext) NOT IN (8,9,10)
OR tableA.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date')

Corrected Query (option 2: using an alias):

DELETE q
FROM tableA q
INNER JOIN tableB u on (u.qlabel = q.entityrole AND u.fieldnum = q.fieldnum) 
WHERE (LENGTH(q.memotext) NOT IN (8,9,10) 
OR q.memotext NOT LIKE '%/%/%')
AND (u.FldFormat = 'Date')

More examples here:
How to Delete using INNER JOIN with SQL Server?

How do you use script variables in psql?

I really miss that feature. Only way to achieve something similar is to use functions.

I have used it in two ways:

  • perl functions that use $_SHARED variable
  • store your variables in table

Perl version:

   CREATE FUNCTION var(name text, val text) RETURNS void AS $$
        $_SHARED{$_[0]} = $_[1];
   $$ LANGUAGE plperl;
   CREATE FUNCTION var(name text) RETURNS text AS $$
        return $_SHARED{$_[0]};
   $$ LANGUAGE plperl;

Table version:

CREATE TABLE var (
  sess bigint NOT NULL,
  key varchar NOT NULL,
  val varchar,
  CONSTRAINT var_pkey PRIMARY KEY (sess, key)
);
CREATE FUNCTION var(key varchar, val anyelement) RETURNS void AS $$
  DELETE FROM var WHERE sess = pg_backend_pid() AND key = $1;
  INSERT INTO var (sess, key, val) VALUES (sessid(), $1, $2::varchar);
$$ LANGUAGE 'sql';

CREATE FUNCTION var(varname varchar) RETURNS varchar AS $$
  SELECT val FROM var WHERE sess = pg_backend_pid() AND key = $1;
$$ LANGUAGE 'sql';

Notes:

  • plperlu is faster than perl
  • pg_backend_pid is not best session identification, consider using pid combined with backend_start from pg_stat_activity
  • this table version is also bad because you have to clear this is up occasionally (and not delete currently working session variables)

Best way to convert pdf files to tiff files

https://pypi.org/project/pdf2tiff/

You could also use pdf2ps, ps2image and then convert from the resulting image to tiff with other utilities (I remember 'paul' [paul - Yet another image viewer (displays PNG, TIFF, GIF, JPG, etc.])

R: `which` statement with multiple conditions

The && function is not vectorized. You need the & function:

EUR <- PCs[which(PCs$V13 < 9 & PCs$V13 > 3), ]

Hadoop MapReduce: Strange Result when Storing Previous Value in Memory in a Reduce Class (Java)

It is very inefficient to store all values in memory, so the objects are reused and loaded one at a time. See this other SO question for a good explanation. Summary:

[...] when looping through the Iterable value list, each Object instance is re-used, so it only keeps one instance around at a given time.

How to convert XML to java.util.Map and vice versa

How about XStream? Not 1 class but 2 jars for many use cases including yours, very simple to use yet quite powerful.

What are the differences between JSON and JSONP?

JSONP is JSON with padding. That is, you put a string at the beginning and a pair of parentheses around it. For example:

//JSON
{"name":"stackoverflow","id":5}
//JSONP
func({"name":"stackoverflow","id":5});

The result is that you can load the JSON as a script file. If you previously set up a function called func, then that function will be called with one argument, which is the JSON data, when the script file is done loading. This is usually used to allow for cross-site AJAX with JSON data. If you know that example.com is serving JSON files that look like the JSONP example given above, then you can use code like this to retrieve it, even if you are not on the example.com domain:

function func(json){
  alert(json.name);
}
var elm = document.createElement("script");
elm.setAttribute("type", "text/javascript");
elm.src = "http://example.com/jsonp";
document.body.appendChild(elm);

How to preview an image before and after upload?

On input type=file add an event onchange="preview()"

For the function preview() type:

thumb.src=URL.createObjectURL(event.target.files[0]);

Live example:

_x000D_
_x000D_
function preview() {
   thumb.src=URL.createObjectURL(event.target.files[0]);
}
_x000D_
<form>
    <input type="file" onchange="preview()">
    <img id="thumb" src="" width="150px"/>
</form>
_x000D_
_x000D_
_x000D_

Trigger to fire only if a condition is met in SQL Server

The _ character is also a wildcard, BTW, but I'm not sure why this wasn't working for you:

CREATE TRIGGER 
    [dbo].[SystemParameterInsertUpdate]
ON 
    [dbo].[SystemParameter]
FOR INSERT, UPDATE 
AS
  BEGIN
    SET NOCOUNT ON
      INSERT INTO SystemParameterHistory 
      (
        Attribute,
        ParameterValue,
        ParameterDescription,
        ChangeDate
      )
    SELECT
      I.Attribute,
      I.ParameterValue,
      I.ParameterDescription,
      I.ChangeDate
    FROM Inserted AS I
    WHERE I.Attribute NOT LIKE 'NoHist[_]%'
END

ToList()-- does it create a new list?

Yes, it creates a new list. This is by design.

The list will contain the same results as the original enumerable sequence, but materialized into a persistent (in-memory) collection. This allows you to consume the results multiple times without incurring the cost of recomputing the sequence.

The beauty of LINQ sequences is that they are composable. Often, the IEnumerable<T> you get is the result of combining multiple filtering, ordering, and/or projection operations. Extension methods like ToList() and ToArray() allow you to convert the computed sequence into a standard collection.

How to correctly set Http Request Header in Angular 2

We can do it nicely using Interceptors. You dont have to set options in all your services neither manage all your error responses, just define 2 interceptors (one to do something before sending the request to server and one to do something before sending the server's response to your service)

  1. Define an AuthInterceptor class to do something before sending the request to the server. You can set the api token (retrieve it from localStorage, see step 4) and other options in this class.
  2. Define an responseInterceptor class to do something before sending the server response to your service (httpClient). You can manage your server response, the most comon use is to check if the user's token is valid (if not clear token from localStorage and redirect to login).
  3. In your app.module import HTTP_INTERCEPTORS from '@angular/common/http'. Then add to your providers the interceptors (AuthInterceptor and responseInterceptor). Doing this your app will consider the interceptors in all our httpClient calls.

  4. At login http response (use http service), save the token at localStorage.

  5. Then use httpClient for all your apirest services.

You can check some good practices on my github proyect here

enter image description here

How to stop IIS asking authentication for default website on localhost

IIS uses Integrated Authentication and by default IE has the ability to use your windows user account...but don't worry, so does Firefox but you'll have to make a quick configuration change.

1) Open up Firefox and type in about:config as the url

2) In the Filter Type in ntlm

3) Double click "network.automatic-ntlm-auth.trusted-uris" and type in localhost and hit enter

4) Write Thank You To Blogger

As Always, Hope this helped you out.

This was copied from link text

Why does LayoutInflater ignore the layout_width and layout_height layout parameters I've specified?

wanna add to main answer above
I tried to follow it but my recyclerView began to stretch every item to a screen
I had to add next line after inflating for reach to goal

itemLayoutView.setLayoutParams(new RecyclerView.LayoutParams(RecyclerView.LayoutParams.MATCH_PARENT, RecyclerView.LayoutParams.WRAP_CONTENT));

I already added these params by xml but it didnot work correctly
and with this line all is ok

PHP date yesterday

How easy :)

date("F j, Y", strtotime( '-1 days' ) );

Example:

echo date("Y-m-j H:i:s", strtotime( '-1 days' ) ); // 2018-07-18 07:02:43

Output:

2018-07-17 07:02:43

Add space between two particular <td>s

Simple answer: give these two tds a style field.

<tr>
<td>One</td>
<td style="padding-right: 10px">Two</td>
<td>Three</td>
<td>Four</td>
</tr>

Tidy one: use class name

<tr>
<td>One</td>
<td class="more-padding-on-right">Two</td>
<td>Three</td>
<td>Four</td>
</tr>

.more-padding-on-right {
  padding-right: 10px;
}

Complex one: using nth-child selector in CSS and specify special padding values for these two, which works in modern browsers.

tr td:nth-child(2) {
  padding-right: 10px;
}?

Command not found when using sudo

Ok this is my solution: in ~/.bash_aliases just add the following:

# ADDS MY PATH WHEN SET AS ROOT
if [ $(id -u) = "0" ]; then
   export PATH=$PATH:/home/your_user/bin 
fi

Voila! Now you can execute your own scripts with sudo or set as ROOT without having to do an export PATH=$PATH:/home/your_user/bin everytime.

Notice that I need to be explicit when adding my PATH since HOME for superuser is /root

How can I split a shell command over multiple lines when using an IF statement?

For Windows/WSL/Cygwin etc users:

Make sure that your line endings are standard Unix line feeds, i.e. \n (LF) only.

Using Windows line endings \r\n (CRLF) line endings will break the command line break.


This is because having \ at the end of a line with Windows line ending translates to \ \r \n.
As Mark correctly explains above:

The line-continuation will fail if you have whitespace after the backslash and before the newline.

This includes not just space () or tabs (\t) but also the carriage return (\r).

SELECT INTO USING UNION QUERY

You have to define a table alias for a derived table in SQL Server:

SELECT x.* 
  INTO [NEW_TABLE]
  FROM (SELECT * FROM TABLE1
        UNION
        SELECT * FROM TABLE2) x

"x" is the table alias in this example.

How to remove MySQL root password

You need to set the password for root@localhost to be blank. There are two ways:

  1. The MySQL SET PASSWORD command:

    SET PASSWORD FOR root@localhost=PASSWORD('');
    
  2. Using the command-line mysqladmin tool:

    mysqladmin -u root -pType_in_your_current_password_here password ''
    

jQuery Ajax File Upload

File upload is not possible through AJAX.
You can upload file, without refreshing page by using IFrame.
You can check further details here.


UPDATE

With XHR2, File upload through AJAX is supported. E.g. through FormData object, but unfortunately it is not supported by all/old browsers.

FormData support starts from following desktop browsers versions.

  • IE 10+
  • Firefox 4.0+
  • Chrome 7+
  • Safari 5+
  • Opera 12+

For more detail, see MDN link.

Suppress InsecureRequestWarning: Unverified HTTPS request is being made in Python2.6

You can disable any Python warnings via the PYTHONWARNINGS environment variable. In this case, you want:

export PYTHONWARNINGS="ignore:Unverified HTTPS request"

To disable using Python code (requests >= 2.16.0):

import urllib3
urllib3.disable_warnings(urllib3.exceptions.InsecureRequestWarning)

For requests < 2.16.0, see original answer below.

Original answer

The reason doing urllib3.disable_warnings() didn't work for you is because it looks like you're using a separate instance of urllib3 vendored inside of requests.

I gather this based on the path here: /usr/lib/python2.6/site-packages/requests/packages/urllib3/connectionpool.py

To disable warnings in requests' vendored urllib3, you'll need to import that specific instance of the module:

import requests
from requests.packages.urllib3.exceptions import InsecureRequestWarning

requests.packages.urllib3.disable_warnings(InsecureRequestWarning)

Minimum rights required to run a windows service as a domain account

I do know that the account needs to have "Log on as a Service" privileges. Other than that, I'm not sure. A quick reference to Log on as a Service can be found here, and there is a lot of information of specific privileges here.

How to set aliases in the Git Bash for Windows?

To configure bash aliases, it's the same as if you were on a Unix platform: put them in a .bashrc in your home:

cd
echo alias ll=\'ls -l\' >> .bashrc

To have this change taken into account you should then either source this file (ie: run source .bashrc) or restart your terminal

(In some cases* you can find equivalent for .bashrc file in C:\Users\<username>\AppData\Local\GitHub\PortableGit_\etc\profile.d\aliases.sh. And you should add aliases in aliases.sh.)

(*this case is when you install Git for Windows GUI release from https://git-scm.com/download/win that contains GitBash)

MIME types missing in IIS 7 for ASP.NET - 404.17

Fix:

I chose the "ISAPI & CGI Restrictions" after clicking the server name (not the site name) in IIS Manager, and right clicked the "ASP.NET v4.0.30319" lines and chose "Allow".

After turning on ASP.NET from "Programs and Features > Turn Windows features on or off", you must install ASP.NET from the Windows command prompt. The MIME types don't ever show up, but after doing this command, I noticed these extensions showed up under the IIS web site "Handler Mappings" section of IIS Manager.

C:\>cd C:\Windows\Microsoft.NET\Framework64\v4.0.30319

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>dir aspnet_reg*
 Volume in drive C is Windows
 Volume Serial Number is 8EE6-5DD0

 Directory of C:\Windows\Microsoft.NET\Framework64\v4.0.30319

03/18/2010  08:23 PM            19,296 aspnet_regbrowsers.exe
03/18/2010  08:23 PM            36,696 aspnet_regiis.exe
03/18/2010  08:23 PM           102,232 aspnet_regsql.exe
               3 File(s)        158,224 bytes
               0 Dir(s)  34,836,508,672 bytes free

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>aspnet_regiis.exe -i
Start installing ASP.NET (4.0.30319).
.....
Finished installing ASP.NET (4.0.30319).

C:\Windows\Microsoft.NET\Framework64\v4.0.30319>

However, I still got this error. But if you do what I mentioned for the "Fix", this will go away.

HTTP Error 404.2 - Not Found
The page you are requesting cannot be served because of the ISAPI and CGI Restriction list settings on the Web server.

Turn off enclosing <p> tags in CKEditor 3.0

MAKE THIS YOUR config.js file code

CKEDITOR.editorConfig = function( config ) {

   //   config.enterMode = 2; //disabled <p> completely
        config.enterMode = CKEDITOR.ENTER_BR // pressing the ENTER KEY input <br/>
        config.shiftEnterMode = CKEDITOR.ENTER_P; //pressing the SHIFT + ENTER KEYS input <p>
        config.autoParagraph = false; // stops automatic insertion of <p> on focus
    };

Submit form with Enter key without submit button?

Change #form to your form's ID

$('#form input').keydown(function(e) {
    if (e.keyCode == 13) {
        $('#form').submit();
    }
});

Or alternatively

$('input').keydown(function(e) {
    if (e.keyCode == 13) {
        $(this).closest('form').submit();
    }
});

Matching an empty input box using CSS

input[value=""], input:not([value])

works with:

<input type="text" />
<input type="text" value="" />

But the style will not change as soon as someone will start typing (you need JS for that).

How to show a confirm message before delete?

Try this. It works for me

 <a href="delete_methode_link" onclick="return confirm('Are you sure you want to Remove?');">Remove</a>

How to convert an array of key-value tuples into an object

When I used the reduce function with acc[i] = cur; it returned a kind of object that I needed to access it like a array using this way obj[i].property. But using this way I have the Object that I wanted and I now can access it like obj.property.

 function convertArraytoObject(arr) {
        var obj = arr.reduce(function (acc, cur, i) {
            acc = cur;
            return acc;
        }, {});
        return obj;
    }

Codeigniter : calling a method of one controller from other

test.php Controller File :

Class Test {
 function demo() {
  echo "Hello";
 }
}

test1.php Controller File :

Class Test1 {
 function demo2() {
  require('test.php');
  $test = new Test();
  $test->demo();
 }
}

I have filtered my Excel data and now I want to number the rows. How do I do that?

Step 1: Highlight the entire column (not including the header) of the column you wish to populate

Step 2: (Using Kutools) On the Insert dropdown, click "Fill Custom List"

Step 3: Click Edit

Step 4: Create your list (For Ex: 1, 2)

Step 5: Choose your new custom list and then click "Fill Range"

DONE!!!

How can I add (simple) tracing in C#?

I followed around five different answers as well as all the blog posts in the previous answers and still had problems. I was trying to add a listener to some existing code that was tracing using the TraceSource.TraceEvent(TraceEventType, Int32, String) method where the TraceSource object was initialised with a string making it a 'named source'.

For me the issue was not creating a valid combination of source and switch elements to target this source. Here is an example that will log to a file called tracelog.txt. For the following code:

TraceSource source = new TraceSource("sourceName");
source.TraceEvent(TraceEventType.Verbose, 1, "Trace message");

I successfully managed to log with the following diagnostics configuration:

<system.diagnostics>
    <sources>
        <source name="sourceName" switchName="switchName">
            <listeners>
                <add
                    name="textWriterTraceListener"
                    type="System.Diagnostics.TextWriterTraceListener"
                    initializeData="tracelog.txt" />
            </listeners>
        </source>
    </sources>

    <switches>
        <add name="switchName" value="Verbose" />
    </switches>
</system.diagnostics>

How to add image to canvas

You need to wait until the image is loaded before you draw it. Try this instead:

var canvas = document.getElementById('viewport'),
context = canvas.getContext('2d');

make_base();

function make_base()
{
  base_image = new Image();
  base_image.src = 'img/base.png';
  base_image.onload = function(){
    context.drawImage(base_image, 0, 0);
  }
}

i.e. draw the image in the onload callback of the image.

Xamarin 2.0 vs Appcelerator Titanium vs PhoneGap

I haven't worked much with Appcelerator Titanium, but I'll put my understanding of it at the end.

I can speak a bit more to the differences between PhoneGap and Xamarin, as I work with these two 5 (or more) days a week.

If you are already familiar with C# and JavaScript, then the question I guess is, does the business logic lie in an area more suited to JavaScript or C#?

PhoneGap

PhoneGap is designed to allow you to write your applications using JavaScript and HTML, and much of the functionality that they do provide is designed to mimic the current proposed specifications for the functionality that will eventually be available with HTML5. The big benefit of PhoneGap in my opinion is that since you are doing the UI with HTML, it can easily be ported between platforms. The downside is, because you are porting the same UI between platforms, it won't feel quite as at home in any of them. Meaning that, without further tweaking, you can't have an application that feels fully at home in iOS and Android, meaning that it has the iOS and Android styling. The majority of your logic can be written using JavaScript, which means it too can be ported between platforms. If the current PhoneGap API does most of what you want, then it's pretty easy to get up and running. If however, there are things you need from the device that are not in the API, then you get into the fun of Plugin Development, which will be in the native device's development language of choice (with one caveat, but I'll get to that), which means you would likely need to get up to speed quickly in Objective-C, Java, etc. The good thing about this model, is you can usually adapt many different native libraries to serve your purpose, and many libraries already have PhoneGap Plugins. Although you might not have much experience with these languages, there will at least be a plethora of examples to work from.

Xamarin

Xamarin.iOS and Xamarin.Android (also known as MonoTouch and MonoDroid), are designed to allow you to have one library of business logic, and use this within your application, and hook it into your UI. Because it's based on .NET 4.5, you get some awesome lambda notations, LINQ, and a whole bunch of other C# awesomeness, which can make writing your business logic less painful. The downside here is that Xamarin expects that you want to make your applications truly feel native on the device, which means that you will likely end up rewriting your UI for each platform, before hooking it together with the business logic. I have heard about MvvmCross, which is designed to make this easier for you, but I haven't really had an opportunity to look into it yet. If you are familiar with the MVVM system in C#, you may want to have a look at this. When it comes to native libraries, MonoTouch becomes interesting. MonoTouch requires a Binding library to tell your C# code how to link into the underlying Objective-C and Java code. Some of these libraries will already have bindings, but if yours doesn't, creating one can be, interesting. Xamarin has made a tool called Objective Sharpie to help with this process, and for the most part, it will get you 95% of the way there. The remaining 5% will probably take 80% of your time attempting to bind a library.

Update

As noted in the comments below, Xamarin has released Xamarin Forms which is a cross platform abstraction around the platform specific UI components. Definitely worth the look.

PhoneGap / Xamarin Hybrid

Now because I said I would get to it, the caveat mentioned in PhoneGap above, is a Hybrid approach, where you can use PhoneGap for part, and Xamarin for part. I have quite a bit of experience with this, and I would caution you against it. Highly. The problem with this, is it is such a no mans' land that if you ever run into issues, almost no one will have come close to what you're doing, and will question what you're trying to do greatly. It is doable, but it's definitely not fun.

Appcelerator Titanium

As I mentioned before, I haven't worked much with Appcelerator Titanium, So for the differences between them, I will suggest you look at Comparing Titanium and Phonegap or Comparison between Corona, Phonegap, Titanium as it has a very thorough description of the differences. Basically, it appears that though they both use JavaScript, how that JavaScript is interpreted is slightly different. With Titanium, you will be writing your JavaScript to the Titanium SDK, whereas with PhoneGap, you will write your application using the PhoneGap API. As PhoneGap is very HTML5 and JavaScript standards compliant, you can use pretty much any JavaScript libraries you want, such as JQuery. With PhoneGap your user interface will be composed of HTML and CSS. With Titanium, you will benefit from their Cross-platform XML which appears to generate Native components. This means it will definitely have a better native look and feel.

How To Set Text In An EditText

If you want to set text at design time in xml file just simple android:text="username" add this property.

<EditText
    android:id="@+id/edtUsername"
    android:layout_width="wrap_content"
    android:layout_height="wrap_content"
    android:text="username"/>

If you want to set text programmatically in Java

EditText edtUsername = findViewById(R.id.edtUsername);
edtUsername.setText("username");

and in kotlin same like java using getter/setter

edtUsername.setText("username")

But if you want to use .text from principle then

edtUsername.text = Editable.Factory.getInstance().newEditable("username")

because of EditText.text requires an editable at firstplace not String

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

Try to use document.createEvent described here https://developer.mozilla.org/en-US/docs/Web/API/document.createEvent

The code for function that simulates click should look something like this:

function simulateClick() {
  var evt = document.createEvent("MouseEvents");
  evt.initMouseEvent("click", true, true, window,
    0, 0, 0, 0, 0, false, false, false, false, 0, null);
  var a = document.getElementById("gift-close"); 
  a.dispatchEvent(evt);      
}

COUNT DISTINCT with CONDITIONS

Try the following statement:

select  distinct A.[Tag],
     count(A.[Tag]) as TAG_COUNT,
     (SELECT count(*) FROM [TagTbl] AS B WHERE A.[Tag]=B.[Tag] AND B.[ID]>0)
     from [TagTbl] AS A GROUP BY A.[Tag]

The first field will be the tag the second will be the whole count the third will be the positive ones count.

How do you list all triggers in a MySQL database?

You can use below to find a particular trigger definition.

SHOW TRIGGERS LIKE '%trigger_name%'\G

or the below to show all the triggers in the database. It will work for MySQL 5.0 and above.

SHOW TRIGGERS\G

When should I use git pull --rebase?

One practice case is when you are working with Bitbucket PR. There is PR open.

Then you decide to rebase the PR remote branch on the latest Master branch. This will change the commit's ids of your PR.

Then you want to add a new commit to the PR branch.

Since you have rebased the remote branch using GUI first you to sync the local branch on PC with the remote branch.

In this case git pull --rebase works like magic.

After git pull --rebase your remote branch and local branch has same history with same commit ids.

Now you can nicely push a new commit without using force or anything.

How do I find all of the symlinks in a directory tree?

One command, no pipes

find . -type l -ls

Explanation: find from the current directory . onwards all references of -type link and list -ls those in detail. Plain and simple...

Expanding upon this answer, here are a couple more symbolic link related find commands:

Find symbolic links to a specific target

find . -lname link_target

Note that link_target is a pattern that may contain wildcard characters.

Find broken symbolic links

find -L . -type l -ls

The -L option instructs find to follow symbolic links, unless when broken.

Find & replace broken symbolic links

find -L . -type l -delete -exec ln -s new_target {} \;

More find examples

More find examples can be found here: https://hamwaves.com/find/

How to open my files in data_folder with pandas using relative path?

# script.py
current_file = os.path.abspath(os.path.dirname(__file__)) #older/folder2/scripts_folder

#csv_filename
csv_filename = os.path.join(current_file, '../data_folder/data.csv')

Ant is using wrong java version

Build file:

<target name="print-version"> 
   <echo>Java/JVM version: ${ant.java.version}</echo> 
   <echo>Java/JVM detail version: ${java.version}</echo> 
</target>

Output:

[echo] Java/JVM version: 1.5
[echo] Java/JVM detail version: 1.5.0_08

Select Rows with id having even number

Sql Server we can use %

select * from orders where ID % 2 = 0;

This can be used in both Mysql and oracle. It is more affection to use mod function that %.

select * from orders where mod(ID,2) = 0

Remove a specific character using awk or sed

tr can be more concise for removing characters than sed or awk, especially when you want to remove different characters from a string.

Removing double quotes:

echo '"Hi"' | tr -d \"
# Produces Hi without quotes

Removing different kinds of brackets:

echo '[{Hi}]' | tr -d {}[]
# Produces Hi without brackets

-d stands for "delete".

Create a tag in a GitHub repository

Using Sourcetree

Here are the simple steps to create a GitHub Tag, when you release build from master.

  1. Open source_tree tab

    step 1

  2. Right click on Tag sections from Tag which appear on left navigation section

    step 2

  3. Click on New Tag()

  4. A dialog appears to Add Tag and Remove Tag
  5. Click on Add Tag from give name to tag (preferred version name of the code)

    step 3

  6. If you want to push the TAG on remote, while creating the TAG ref: step 5 which gives checkbox push TAG to origin check it and pushed tag appears on remote repository

  7. In case while creating the TAG if you have forgotten to check the box Push to origin, you can do it later by right-clicking on the created TAG, click on Push to origin. enter image description here

De-obfuscate Javascript code to make it readable again

From the first link on google;

function call_func(_0x41dcx2) {
 var _0x41dcx3 = eval('(' + _0x41dcx2 + ')');
 var _0x41dcx4 = document['createElement']('div');
 var _0x41dcx5 = _0x41dcx3['id'];
 var _0x41dcx6 = _0x41dcx3['Student_name'];
 var _0x41dcx7 = _0x41dcx3['student_dob'];
 var _0x41dcx8 = '<b>ID:</b>';
 _0x41dcx8 += '<a href="/learningyii/index.php?r=student/view&amp; id=' + _0x41dcx5 + '">' + _0x41dcx5 + '</a>';
 _0x41dcx8 += '<br/>';
 _0x41dcx8 += '<b>Student Name:</b>';
 _0x41dcx8 += _0x41dcx6;
 _0x41dcx8 += '<br/>';
 _0x41dcx8 += '<b>Student DOB:</b>';
 _0x41dcx8 += _0x41dcx7;
 _0x41dcx8 += '<br/>';
 _0x41dcx4['innerHTML'] = _0x41dcx8;
 _0x41dcx4['setAttribute']('class', 'view');
 $('#StudentGridViewId')['find']('.items')['prepend'](_0x41dcx4);
};

It won't get you all the way back to source, and that's not really possible, but it'll get you out of a hole.

Git push won't do anything (everything up-to-date)

Thanks to Sam Stokes. According to his answer you can solve the problem with different way (I used this way). After updating your develop directory you should reinitialize it

git init

Then you can commit and push updates to master

Deleting all pending tasks in celery / rabbitmq

I found that celery purge doesn't work for my more complex celery config. I use multiple named queues for different purposes:

$ sudo rabbitmqctl list_queues -p celery name messages consumers
Listing queues ...  # Output sorted, whitespaced for readability
celery                                          0   2
[email protected]                      0   1
[email protected]                      0   1
apns                                            0   1
[email protected]                        0   1
analytics                                       1   1
[email protected]                   0   1
bcast.361093f1-de68-46c5-adff-d49ea8f164c0      0   1
bcast.a53632b0-c8b8-46d9-bd59-364afe9998c1      0   1
celeryev.c27b070d-b07e-4e37-9dca-dbb45d03fd54   0   1
celeryev.c66a9bed-84bd-40b0-8fe7-4e4d0c002866   0   1
celeryev.b490f71a-be1a-4cd8-ae17-06a713cc2a99   0   1
celeryev.9d023165-ab4a-42cb-86f8-90294b80bd1e   0   1

The first column is the queue name, the second is the number of messages waiting in the queue, and the third is the number of listeners for that queue. The queues are:

  • celery - Queue for standard, idempotent celery tasks
  • apns - Queue for Apple Push Notification Service tasks, not quite as idempotent
  • analytics - Queue for long running nightly analytics
  • *.pidbox - Queue for worker commands, such as shutdown and reset, one per worker (2 celery workers, one apns worker, one analytics worker)
  • bcast.* - Broadcast queues, for sending messages to all workers listening to a queue (rather than just the first to grab it)
  • celeryev.* - Celery event queues, for reporting task analytics

The analytics task is a brute force tasks that worked great on small data sets, but now takes more than 24 hours to process. Occasionally, something will go wrong and it will get stuck waiting on the database. It needs to be re-written, but until then, when it gets stuck I kill the task, empty the queue, and try again. I detect "stuckness" by looking at the message count for the analytics queue, which should be 0 (finished analytics) or 1 (waiting for last night's analytics to finish). 2 or higher is bad, and I get an email.

celery purge offers to erase tasks from one of the broadcast queues, and I don't see an option to pick a different named queue.

Here's my process:

$ sudo /etc/init.d/celeryd stop  # Wait for analytics task to be last one, Ctrl-C
$ ps -ef | grep analytics  # Get the PID of the worker, not the root PID reported by celery
$ sudo kill <PID>
$ sudo /etc/init.d/celeryd stop  # Confim dead
$ python manage.py celery amqp queue.purge analytics
$ sudo rabbitmqctl list_queues -p celery name messages consumers  # Confirm messages is 0
$ sudo /etc/init.d/celeryd start

Why should hash functions use a prime number modulus?

Just to provide an alternate viewpoint there's this site:

http://www.codexon.com/posts/hash-functions-the-modulo-prime-myth

Which contends that you should use the largest number of buckets possible as opposed to to rounding down to a prime number of buckets. It seems like a reasonable possibility. Intuitively, I can certainly see how a larger number of buckets would be better, but I'm unable to make a mathematical argument of this.

Convert a tensor to numpy array in Tensorflow?

Any tensor returned by Session.run or eval is a NumPy array.

>>> print(type(tf.Session().run(tf.constant([1,2,3]))))
<class 'numpy.ndarray'>

Or:

>>> sess = tf.InteractiveSession()
>>> print(type(tf.constant([1,2,3]).eval()))
<class 'numpy.ndarray'>

Or, equivalently:

>>> sess = tf.Session()
>>> with sess.as_default():
>>>    print(type(tf.constant([1,2,3]).eval()))
<class 'numpy.ndarray'>

EDIT: Not any tensor returned by Session.run or eval() is a NumPy array. Sparse Tensors for example are returned as SparseTensorValue:

>>> print(type(tf.Session().run(tf.SparseTensor([[0, 0]],[1],[1,2]))))
<class 'tensorflow.python.framework.sparse_tensor.SparseTensorValue'>

TypeError: unsupported operand type(s) for -: 'list' and 'list'

This question has been answered but I feel I should also mention another potential cause. This is a direct result of coming across the same error message but for different reasons. If your list/s are empty the operation will not be performed. check your code for indents and typos

Add Custom Headers using HttpWebRequest

You should do ex.StackTrace instead of ex.ToString()

How can I make a CSS glass/blur effect work for an overlay?

If you're looking for a reliable cross-browser approach today, you won't find a great one. The best option you have is to create two images (this could be automated in some environments), and arrange them such that one overlays the other. I've created a simple example below:

<figure class="js">
    <img src="http://i.imgur.com/3oenmve.png" />
    <img src="http://i.imgur.com/3oenmve.png?1" class="blur" />
</figure>
figure.js {
    position: relative;
    width: 250px; height: 250px;
}

figure.js .blur {
    top: 0; left: 0;
    position: absolute;
    clip: rect( 0, 250px, 125px, 0 );
}

Though effective, even this approach isn't necessarily ideal. That being said, it does yield the desired result.

enter image description here

What is ".NET Core"?

Microsoft recognized the future web open source paradigm and decided to open .NET to other operating systems. .NET Core is a .NET Framework for Mac and Linux. It is a “lightweight” .NET Framework, so some features/libraries are missing.

On Windows, I would still run .NET Framework and Visual Studio 2015. .NET Core is more friendly with the open source world like Node.js, npm, Yeoman, Docker, etc.

You can develop full-fledged web sites and RESTful APIs on Mac or Linux with Visual Studio Code + .NET Core which wasn't possible before. So if you love Mac or Ubuntu and you are a .NET developer then go ahead and set it up.

For Mono vs. .NET Core, Mono was developed as a .NET Framework for Linux which is now acquired by Microsoft (company called Xamarin) and used in mobile development. Eventually, Microsoft may merge/migrate Mono to .NET Core. I would not worry about Mono right now.

calculating number of days between 2 columns of dates in data frame

In Ronald's example, if the date formats are different (as displayed below) then modify the format parameter

survey <- data.frame(date=c("2012-07-26","2012-07-25"),tx_start=c("2012-01-01","2012-01-01"))

survey$date_diff <- as.Date(as.character(survey$date), format="%Y-%m-%d")-
              as.Date(as.character(survey$tx_start), format="%Y-%m-%d")

survey:

   date      tx_start     date_diff
1 2012-07-26     2012-01-01    207 days
2 2012-07-25     2012-01-01    206 days

How to check object is nil or not in swift?

func isObjectValid(someObject: Any?) -> Any? {
    if someObject is String {
        if let someObject = someObject as? String {
            return someObject
        }else {
            return ""
        }
    }else if someObject is Array<Any> {
        if let someObject = someObject as? Array<Any> {
            return someObject
        }else {
            return []
        }
    }else if someObject is Dictionary<AnyHashable, Any> {
        if let someObject = someObject as? Dictionary<String, Any> {
            return someObject
        }else {
            return [:]
        }
    }else if someObject is Data {
        if let someObject = someObject as? Data {
            return someObject
        }else {
            return Data()
        }
    }else if someObject is NSNumber {
        if let someObject = someObject as? NSNumber{
            return someObject
        }else {
            return NSNumber.init(booleanLiteral: false)
        }
    }else if someObject is UIImage {
        if let someObject = someObject as? UIImage {
            return someObject
        }else {
            return UIImage()
        }
    }
    else {
        return "InValid Object"
    }
}

This function checks any kind of object and return's default value of the kind of object, if object is invalid.

How to create a HTML Table from a PHP array?

PHP code:

$multiarray = array (

    array("name"=>"Argishti", "surname"=>"Yeghiazaryan"),
    array("name"=>"Armen", "surname"=>"Mkhitaryan"),
    array("name"=>"Arshak", "surname"=>"Aghabekyan"),

);

$count = 0;

foreach ($multiarray as $arrays){
    $count++;
    echo "<table>" ;               

    echo "<span>table $count</span>";
    echo "<tr>";
    foreach ($arrays as $names => $surnames){

        echo "<th>$names</th>";
        echo "<td>$surnames</td>";

    }
    echo "</tr>";
    echo "</table>";
}

CSS:

table {
    font-family: arial, sans-serif;
    border-collapse: collapse;
    width: 100%;
}

td, th {
    border: 1px solid #dddddd;
    text-align: left;
    padding: 8px;``
}

How to make JQuery-AJAX request synchronous

I added dataType as json and made the response as json:

PHP

echo json_encode(array('success'=>$res)); //send the response as json **use this instead of echo $res in your php file**

JavaScript

  var ajaxSubmit = function(formE1) {

        var password = $.trim($('#employee_password').val());    
        $.ajax({
            type: "POST",
            async: "false",
            url: "checkpass.php",
            data: "password="+password,
            dataType:'json',  //added this so the response is in json
            success: function(result) {
                var arr=result.success;
                if(arr == "Successful")
                {    return true;
                }
                else
                {    return false;
                }
            }
        });

  return false
}

MySQL select one column DISTINCT, with corresponding other columns

SELECT firstName, ID, LastName from tableName GROUP BY firstName

How to make the tab character 4 spaces instead of 8 spaces in nano?

In nano 2.2.6 the line in ~/.nanorc to do this seems to be

set tabsize 4

Setting tabspace gave me the error: 'Unknown flag "tabspace"'

pass array to method Java

You do this:

private void PassArray() {
    String[] arrayw = new String[4]; //populate array
    PrintA(arrayw);
}

private void PrintA(String[] a) {
    //do whatever with array here
}

Just pass it as any other variable.
In Java, arrays are passed by reference.

Loop through an array of strings in Bash?

If you are using Korn shell, there is "set -A databaseName ", else there is "declare -a databaseName"

To write a script working on all shells,

 set -A databaseName=("db1" "db2" ....) ||
        declare -a databaseName=("db1" "db2" ....)
# now loop 
for dbname in "${arr[@]}"
do
   echo "$dbname"  # or whatever

done

It should be work on all shells.

Confusing error in R: Error in scan(file, what, nmax, sep, dec, quote, skip, nlines, na.strings, : line 1 did not have 42 elements)

read.table wants to return a data.frame, which must have an element in each column. Therefore R expects each row to have the same number of elements and it doesn't fill in empty spaces by default. Try read.table("/PathTo/file.csv" , fill = TRUE ) to fill in the blanks.

e.g.

read.table( text= "Element1 Element2
Element5 Element6 Element7" , fill = TRUE , header = FALSE )
#        V1       V2       V3
#1 Element1 Element2         
#2 Element5 Element6 Element7

A note on whether or not to set header = FALSE... read.table tries to automatically determine if you have a header row thus:

header is set to TRUE if and only if the first row contains one fewer field than the number of columns

How to split a comma-separated string?

First you can split names like this

String animals = "dog, cat, bear, elephant,giraffe";

String animals_list[] = animals.split(",");

to Access your animals

String animal1 = animals_list[0];
String animal2 = animals_list[1];
String animal3 = animals_list[2];
String animal4 = animals_list[3];

And also you want to remove white spaces and comma around animal names

String animals_list[] = animals.split("\\s*,\\s*");

What data type to use in MySQL to store images?

Perfect answer for your question can be found on MYSQL site itself.refer their manual(without using PHP)

http://forums.mysql.com/read.php?20,17671,27914

According to them use LONGBLOB datatype. with that you can only store images less than 1MB only by default,although it can be changed by editing server config file.i would also recommend using MySQL workBench for ease of database management

Inverse dictionary lookup in Python

Make a reverse dictionary

reverse_dictionary = {v:k for k,v in dictionary.items()} 

If you have a lot of reverse lookups to do

ECONNREFUSED error when connecting to mongodb from node.js

OK, this was another case of not being truly forthcoming in the info I posted above. My node.js app was very simple, but I was including another couple lines in my node.js code that apparently caused this issue.

Specifically, I had another variable declared which was calling some other code that made a separate database call using incorrect db info. This is why, when using Xinzz's code, the console log error seemed not to change. It wasn't actually the mongoose.connect command that was throwing the error!

Lesson learned, localize the problem and comment out unrelated code! Sorry guys, I knew this was me being dumb.

My C# application is returning 0xE0434352 to Windows Task Scheduler but it is not crashing

It is permission issue in my case the task scheduler has a user which doesn't have permission on the server in which the database is present.

How to find all links / pages on a website

Check out linkchecker—it will crawl the site (while obeying robots.txt) and generate a report. From there, you can script up a solution for creating the directory tree.

React "after render" code?

I am not going to pretend I know why this particular function works, however window.getComputedStyle works 100% of the time for me whenever I need to access DOM elements with a Ref in a useEffect — I can only presume it will work with componentDidMount as well.

I put it at the top of the code in a useEffect and it appears as if it forces the effect to wait for the elements to be painted before it continues with the next line of code, but without any noticeable delay such as using a setTimeout or an async sleep function. Without this, the Ref element returns as undefined when I try to access it.

const ref = useRef(null);

useEffect(()=>{
    window.getComputedStyle(ref.current);
    // Next lines of code to get element and do something after getComputedStyle().
});

return(<div ref={ref}></div>);

when I try to open an HTML file through `http://localhost/xampp/htdocs/index.html` it says unable to connect to localhost

All created by user files saved in C:\xampp\htdocs directory by default, so no need to type the default path in a browser window, just type http://localhost/yourfilename.php or http://localhost/yourfoldername/yourfilename.php this will show you the content of your new page.

psql: command not found Mac

You have got the PATH slightly wrong. You need the PATH to "the containing directory", not the actual executable itself.

Your PATH should be set like this:

export PATH=/Library/PostgreSQL/9.5/bin:$PATH

without the extra sql part in it. Also, you must remove the spaces around the equals sign.

Keywords: Postgresql, PATH, macOS, OSX, psql

Javascript Regular Expression Remove Spaces

Remove all spaces in string

// Remove only spaces
`
Text with spaces 1 1     1     1 
and some
breaklines

`.replace(/ /g,'');
"
Textwithspaces1111
andsome
breaklines

"

// Remove spaces and breaklines
`
Text with spaces 1 1     1     1
and some
breaklines

`.replace(/\s/g,'');
"Textwithspaces1111andsomebreaklines"

Iterating through map in template

As Herman pointed out, you can get the index and element from each iteration.

{{range $index, $element := .}}{{$index}}
{{range $element}}{{.Value}}
{{end}}
{{end}}

Working example:

package main

import (
    "html/template"
    "os"
)

type EntetiesClass struct {
    Name string
    Value int32
}

// In the template, we use rangeStruct to turn our struct values
// into a slice we can iterate over
var htmlTemplate = `{{range $index, $element := .}}{{$index}}
{{range $element}}{{.Value}}
{{end}}
{{end}}`

func main() {
    data := map[string][]EntetiesClass{
        "Yoga": {{"Yoga", 15}, {"Yoga", 51}},
        "Pilates": {{"Pilates", 3}, {"Pilates", 6}, {"Pilates", 9}},
    }

    t := template.New("t")
    t, err := t.Parse(htmlTemplate)
    if err != nil {
        panic(err)
    }

    err = t.Execute(os.Stdout, data)
    if err != nil {
        panic(err)
    }

}

Output:

Pilates
3
6
9

Yoga
15
51

Playground: http://play.golang.org/p/4ISxcFKG7v

Remove trailing spaces automatically or with a shortcut

In recent Visual Studio Code versions you can find settings here:

Menu FilePreferenceSettingsText EditorFiles → (scroll down a bit) Trim Trailing Whitespace

This is for trimming whitespace when saving a file.

Or you can search "Trim Trailing Whitespace" in the top search bar.

Custom Cell Row Height setting in storyboard is not responding

For dynamic cells, rowHeight set on the UITableView always overrides the individual cells' rowHeight.

This behavior is, IMO, a bug. Anytime you have to manage your UI in two places it is prone to error. For example, if you change your cell size in the storyboard, you have to remember to change them in the heightForRowAtIndexPath: as well. Until Apple fixes the bug, the current best workaround is to override heightForRowAtIndexPath:, but use the actual prototype cells from the storyboard to determine the height rather than using magic numbers. Here's an example:

- (CGFloat)tableView:(UITableView *)tableView 
           heightForRowAtIndexPath:(NSIndexPath *)indexPath
{
    /* In this example, there is a different cell for
       the top, middle and bottom rows of the tableView.
       Each type of cell has a different height.
       self.model contains the data for the tableview 
    */
    static NSString *CellIdentifier;
    if (indexPath.row == 0) 
        CellIdentifier = @"CellTop";
    else if (indexPath.row + 1 == [self.model count] )
        CellIdentifier = @"CellBottom";
    else
        CellIdentifier = @"CellMiddle";

    UITableViewCell *cell = 
              [self.tableView dequeueReusableCellWithIdentifier:CellIdentifier];

    return cell.bounds.size.height;
}

This will ensure any changes to your prototype cell heights will automatically be picked up at runtime and you only need to manage your UI in one place: the storyboard.

Hashset vs Treeset

If you aren't inserting enough elements to result in frequent rehashings (or collisions, if your HashSet can't resize), a HashSet certainly gives you the benefit of constant time access. But on sets with lots of growth or shrinkage, you may actually get better performance with Treesets, depending on the implementation.

Amortized time can be close to O(1) with a functional red-black tree, if memory serves me. Okasaki's book would have a better explanation than I can pull off. (Or see his publication list)

How could others, on a local network, access my NodeJS app while it's running on my machine?

your node.js server is running on a port determined at the end of the script usually. Sometimes 3000. but can be anything. The correct way for others to access is as you say...

http://your.network.ip.address:port/ e.g. http://192.168.0.3:3000

check you have the correct port - and the ip address on the network - not internet ip.

Otherwise, maybe the ports are being blocked by your router. Try using 8080 or 80 to get around this - otherwise re-configure your router.

Disable beep of Linux Bash on Windows 10

To disable the beeps when ssh-ing in a remote machine, simply create the same ~/.inputrc and ~/.vimrc files on the remote machine to stop ssh itself from beeping.

See the answer from @Nemo for the contents of each file.

Git: Pull from other remote

git pull is really just a shorthand for git pull <remote> <branchname>, in most cases it's equivalent to git pull origin master. You will need to add another remote and pull explicitly from it. This page describes it in detail:

http://help.github.com/forking/

Lists in ConfigParser

json.loads & ast.literal_eval seems to be working but simple list within config is treating each character as byte so returning even square bracket....

meaning if config has fieldvalue = [1,2,3,4,5]

then config.read(*.cfg) config['fieldValue'][0] returning [ in place of 1

How to get a table creation script in MySQL Workbench?

Right-click on the relevant table and choose either of:

  • Copy to Clipboard > Create Statement
  • Send to SQL Editor > Create Statement

That seems to work for me.

Copy Notepad++ text with formatting?

Horrible to look for this failure:

Copy .dll to here:

\Program Files\Notepad++\plugins --> put it here

Restart the notepad++

and now you are able to use the copy commands!!!

Angular 2 @ViewChild annotation returns undefined

My workaround was to use [style.display]="getControlsOnStyleDisplay()" instead of *ngIf="controlsOn". The block is there but it is not displayed.

@Component({
selector: 'app',
template:  `
    <controls [style.display]="getControlsOnStyleDisplay()"></controls>
...

export class AppComponent {
  @ViewChild(ControlsComponent) controls:ControlsComponent;

  controlsOn:boolean = false;

  getControlsOnStyleDisplay() {
    if(this.controlsOn) {
      return "block";
    } else {
      return "none";
    }
  }
....

How can I update npm on Windows?

Like some people, I needed to combine multiple answers, and I also needed to set a proxy.

This should work for anyone. I have zero desire to run an EXE file or MSI file .. uninstall/ reinstall, or manually delete files and folders. That is so 1999 :P

  1. Run this to update NPM:

    Run PowerShell as administrator

    npm i -g npm    // This works
    

    I am not thinking this code actually upgrades your npm version below

    Set-ExecutionPolicy Unrestricted -Scope CurrentUser -Force
    npm install -g npm-windows-upgrade
    npm-windows-upgrade
    
    (courtesy of "Robert" answer)
    

Run this to update Node.js:

wget https://nodejs.org/download/release/latest/win-x64/node.exe -OutFile 'C:\Program Files (x86)\nodejs\node.exe'    (courtesy of BrunoLM answer)

If you get `wget : Could not find a part of the path .... "**, see below ...scroll down. Reading Web Response... It's at least punching through the firewall /proxy (if you have one or have already ran the code get through ...

Otherwise

You might need to set your proxy

npm config set proxy "http://proxy.yourcorp.com:811"    (yes, use quotes)

2 possible errors

  1. It cannot find path of the path solution "where.exe node" (courtesy of Lonnie Best Answer)

    E.g. if Node.js is NOT living in "Program Files (x86)" perhaps with where.exe, it is living in 'C:\Program Files\nodejs\node.exe'.

    wget https://nodejs.org/download/release/latest/win-x64/node.exe -OutFile 'C:\Program Files\nodejs\node.exe'
    
  2. Now perhaps it tries to upgrade but you get another error, "node.exe is being used by another process."

    • Close /shutdown other consoles .. command prompts and PowerShell windows, etc. Even if you're using npm in a command prompt, close it.

npm -v (3.10.8)

node -v ( v6.6.0)

DONE. I'm at the version that I want.

Pandas DataFrame: replace all values in a column, based on condition

Another option is to use a list comprehension:

df['First Season'] = [1 if year > 1990 else year for year in df['First Season']]

How do I get the absolute directory of a file in bash?

I have been using readlink -f works on linux

so

FULL_PATH=$(readlink -f filename)
DIR=$(dirname $FULL_PATH)

PWD=$(pwd)

cd $DIR

#<do more work>

cd $PWD

Activate a virtualenv with a Python script

It turns out that, yes, the problem is not simple, but the solution is.

First I had to create a shell script to wrap the "source" command. That said I used the "." instead, because I've read that it's better to use it than source for Bash scripts.

#!/bin/bash
. /path/to/env/bin/activate

Then from my Python script I can simply do this:

import os
os.system('/bin/bash --rcfile /path/to/myscript.sh')

The whole trick lies within the --rcfile argument.

When the Python interpreter exits it leaves the current shell in the activated environment.

Win!

How to enable Logger.debug() in Log4j

You need to set the logger level to the lowest you want to display. For example, if you want to display DEBUG messages, you need to set the logger level to DEBUG.

The Apache log4j manual has a section on Configuration.

Can I do a max(count(*)) in SQL?

     select top 1 yr,count(*)  from movie
join casting on casting.movieid=movie.id
join actor on casting.actorid = actor.id
where actor.name = 'John Travolta'
group by yr order by 2 desc

How to get a random number in Ruby

Well, I figured it out. Apparently there is a builtin (?) function called rand:

rand(n + 1)

If someone answers with a more detailed answer, I'll mark that as the correct answer.

Call a stored procedure with another in Oracle

Calling one procedure from another procedure:

One for a normal procedure:

CREATE OR REPLACE SP_1() AS 
BEGIN
/*  BODY */
END SP_1;

Calling procedure SP_1 from SP_2:

CREATE OR REPLACE SP_2() AS
BEGIN
/* CALL PROCEDURE SP_1 */
SP_1();
END SP_2;

Call a procedure with REFCURSOR or output cursor:

CREATE OR REPLACE SP_1
(
oCurSp1 OUT SYS_REFCURSOR
) AS
BEGIN
/*BODY */
END SP_1;

Call the procedure SP_1 which will return the REFCURSOR as an output parameter

CREATE OR REPLACE SP_2 
(
oCurSp2 OUT SYS_REFCURSOR
) AS `enter code here`
BEGIN
/* CALL PROCEDURE SP_1 WITH REF CURSOR AS OUTPUT PARAMETER */
SP_1(oCurSp2);
END SP_2;

UILabel is not auto-shrinking text to fit label size

Coming late to the party, but since I had the additional requirement of having one word per line, this one addition did the trick for me:

label.numberOfLines = [labelString componentsSeparatedByString:@" "].count;

Apple Docs say:

Normally, the label text is drawn with the font you specify in the font property. If this property is set to YES, however, and the text in the text property exceeds the label’s bounding rectangle, the receiver starts reducing the font size until the string fits or the minimum font size is reached. In iOS 6 and earlier, this property is effective only when the numberOfLines property is set to 1.

But this is a lie. A lie I tell you! It's true for all iOS versions. Specifically, this is true when using a UILabel within a UICollectionViewCell for which the size is determined by constraints adjusted dynamically at runtime via custom layout (ex. self.menuCollectionViewLayout.itemSize = size).

So when used in conjunction with adjustsFontSizeToFitWidth and minimumScaleFactor, as mentioned in previous answers, programmatically setting numberOfLines based on word count solved the autoshrink problem. Doing something similar based on word count or even character count might produce a "close enough" solution.

How to list imported modules?

This code lists modules imported by your module:

import sys
before = [str(m) for m in sys.modules]
import my_module
after = [str(m) for m in sys.modules]
print [m for m in after if not m in before]

It should be useful if you want to know what external modules to install on a new system to run your code, without the need to try again and again.

It won't list the sys module or modules imported from it.

How to convert from int to string in objective c: example code

int val1 = [textBox1.text integerValue];
int val2 = [textBox2.text integerValue];

int resultValue = val1 * val2;

textBox3.text = [NSString stringWithFormat: @"%d", resultValue];

java.lang.NoClassDefFoundError: org.slf4j.LoggerFactory

Download slf4j-1.7.5.zip

It holds different jar files.

Go to -> Integration folder after extracting zip and include following jar files

  1. slf4j-api-2.0.99
  2. slf4j-simple-1.6.99
  3. junit-3.8.1

Executing <script> elements inserted with .innerHTML

The OP's script doesn't work in IE 7. With help from SO, here's a script that does:

exec_body_scripts: function(body_el) {
  // Finds and executes scripts in a newly added element's body.
  // Needed since innerHTML does not run scripts.
  //
  // Argument body_el is an element in the dom.

  function nodeName(elem, name) {
    return elem.nodeName && elem.nodeName.toUpperCase() ===
              name.toUpperCase();
  };

  function evalScript(elem) {
    var data = (elem.text || elem.textContent || elem.innerHTML || "" ),
        head = document.getElementsByTagName("head")[0] ||
                  document.documentElement,
        script = document.createElement("script");

    script.type = "text/javascript";
    try {
      // doesn't work on ie...
      script.appendChild(document.createTextNode(data));      
    } catch(e) {
      // IE has funky script nodes
      script.text = data;
    }

    head.insertBefore(script, head.firstChild);
    head.removeChild(script);
  };

  // main section of function
  var scripts = [],
      script,
      children_nodes = body_el.childNodes,
      child,
      i;

  for (i = 0; children_nodes[i]; i++) {
    child = children_nodes[i];
    if (nodeName(child, "script" ) &&
      (!child.type || child.type.toLowerCase() === "text/javascript")) {
          scripts.push(child);
      }
  }

  for (i = 0; scripts[i]; i++) {
    script = scripts[i];
    if (script.parentNode) {script.parentNode.removeChild(script);}
    evalScript(scripts[i]);
  }
};

maven "cannot find symbol" message unhelpful

If you are using Intellij and the above solutions are not working try: File > Invalidate Caches / Restart

This worked for me. Sometimes when you are working through multiple branches, the IDE uses its cache and cannot find the file in the cache hence it shows error during compilation.

seek() function?

When you open a file, the system points to the beginning of the file. Any read or write you do will happen from the beginning. A seek() operation moves that pointer to some other part of the file so you can read or write at that place.

So, if you want to read the whole file but skip the first 20 bytes, open the file, seek(20) to move to where you want to start reading, then continue with reading the file.

Or say you want to read every 10th byte, you could write a loop that does seek(9, 1) (moves 9 bytes forward relative to the current positions), read(1) (reads one byte), repeat.

How to enable explicit_defaults_for_timestamp?

I'm Using Windows 8.1 and I use this command

c:\wamp\bin\mysql\mysql5.6.12\bin\mysql.exe

instead of

 c:\wamp\bin\mysql\mysql5.6.12\bin\mysqld

and it works fine..

Redis - Connect to Remote Server

First I'd check to verify it is listening on the IPs you expect it to be:

netstat -nlpt | grep 6379

Depending on how you start/stop you may not have actually restarted the instance when you thought you had. The netstat will tell you if it is listening where you think it is. If not, restart it and be sure it restarts. If it restarts and still is not listening where you expect, check your config file just to be sure.

After establishing it is listening where you expect it to, from a remote node which should have access try:

redis-cli -h REMOTE.HOST ping

You could also try that from the local host but use the IP you expect it to be listening on instead of a hostname or localhost. You should see it PONG in response in both cases.

If not, your firewall(s) is/are blocking you. This would be either the local IPTables or possibly a firewall in between the nodes. You could add a logging statement to your IPtables configuration to log connections over 6379 to see what is happening. Also, trying he redis ping from local and non-local to the same IP should be illustrative. If it responds locally but not remotely, I'd lean toward an intervening firewall depending on the complexity of your on-node IP Tables rules.

Cheap way to search a large text file for a string

You could do a simple find:

f = open('file.txt', 'r')
lines = f.read()
answer = lines.find('string')

A simple find will be quite a bit quicker than regex if you can get away with it.

String vs. StringBuilder

String concatenation will cost you more. In Java, You can use either StringBuffer or StringBuilder based on your need. If you want a synchronized, and thread safe implementation, go for StringBuffer. This will be faster than the String concatenation.

If you do not need synchronized or Thread safe implementation, go for StringBuilder. This will be faster than String concatenation and also faster than StringBuffer as their is no synchorization overhead.

List an Array of Strings in alphabetical order

Weird, your code seems to work for me:

import java.util.Arrays;

public class Test
{
    public static void main(String[] args)
    {
        // args is the list of guests
        Arrays.sort(args);
        for(int i = 0; i < args.length; i++)
            System.out.println(args[i]);
    }
}

I ran that code using "java Test Bobby Joe Angel" and here is the output:

$ java Test Bobby Joe Angel
Angel
Bobby
Joe

Dynamic variable names in Bash

This will work too

my_country_code="green"
x="country"

eval z='$'my_"$x"_code
echo $z                 ## o/p: green

In your case

eval final_val='$'magic_way_to_define_magic_variable_"$1"
echo $final_val

Http 415 Unsupported Media type error with JSON

The 415 (Unsupported Media Type) status code indicates that the origin server is refusing to service the request because the payload is in a format not supported by this method on the target resource. The format problem might be due to the request's indicated Content-Type or Content-Encoding, or as a result of inspecting the data directly. DOC

How to scale images to screen size in Pygame

If you scale 1600x900 to 1280x720 you have

scale_x = 1280.0/1600
scale_y = 720.0/900

Then you can use it to find button size, and button position

button_width  = 300 * scale_x
button_height = 300 * scale_y

button_x = 1440 * scale_x
button_y = 860  * scale_y

If you scale 1280x720 to 1600x900 you have

scale_x = 1600.0/1280
scale_y = 900.0/720

and rest is the same.


I add .0 to value to make float - otherwise scale_x, scale_y will be rounded to integer - in this example to 0 (zero) (Python 2.x)

Error handling with try and catch in Laravel

You are inside a namespace so you should use \Exception to specify the global namespace:

try {

  $this->buildXMLHeader();

} catch (\Exception $e) {

    return $e->getMessage();
}

In your code you've used catch (Exception $e) so Exception is being searched in/as:

App\Services\PayUService\Exception

Since there is no Exception class inside App\Services\PayUService so it's not being triggered. Alternatively, you can use a use statement at the top of your class like use Exception; and then you can use catch (Exception $e).

How to access JSON Object name/value?

Try this code..

function (data) {


var json = jQuery.parseJSON(data);
alert( json.name );


}

Get Time from Getdate()

You might want to check out this old thread.

If you can omit AM/PM portion and using SQL Server 2008, you should go with the approach suggested here

To get the rid from nenoseconds in time(SQL Server 2008), do as below :

SELECT CONVERT(TIME(0),GETDATE()) AS HourMinuteSecond

I hope it helps!!

How to select an item in a ListView programmatically?

        int i=99;//is what row you want to select and focus
        listViewRamos.FocusedItem = listViewRamos.Items[0];
        listViewRamos.Items[i].Selected = true;
        listViewRamos.Select();
        listViewRamos.EnsureVisible(i);//This is the trick

How to close a web page on a button click, a hyperlink or a link button click?

double click the button and add write // this.close();

  private void buttonClick(object sender, EventArgs e)
{
    this.Close();
}

About the Full Screen And No Titlebar from manifest

In AndroidManifest.xml, set android:theme="@android:style/Theme.NoTitleBar.Fullscreen"in application tag.

Individual activities can override the default by setting their own theme attributes.

Reversing a string in C

Since you say you want to get fancy, perhaps you'll want to exchange your characters using an XOR swap.

Can not find the tag library descriptor for "http://java.sun.com/jsp/jstl/core"

If you are using maven your pom's <dependencies> tag should look like:

<dependencies>
    <dependency>
        <groupId>javax.servlet</groupId>
        <artifactId>servlet-api</artifactId>
        <version>2.5</version>
    </dependency>
    <dependency>
        <groupId>javax.servlet.jsp.jstl</groupId>
        <artifactId>javax.servlet.jsp.jstl-api</artifactId>
        <version>1.2.1</version>
    </dependency>
    <dependency>
        <groupId>taglibs</groupId>
        <artifactId>standard</artifactId>
        <version>1.1.2</version>
    </dependency>
</dependencies>

It works for me.

How to merge two arrays in JavaScript and de-duplicate items

Array.prototype.add = function(b){
    var a = this.concat();                // clone current object
    if(!b.push || !b.length) return a;    // if b is not an array, or empty, then return a unchanged
    if(!a.length) return b.concat();      // if original is empty, return b

    // go through all the elements of b
    for(var i = 0; i < b.length; i++){
        // if b's value is not in a, then add it
        if(a.indexOf(b[i]) == -1) a.push(b[i]);
    }
    return a;
}

// Example:
console.log([1,2,3].add([3, 4, 5])); // will output [1, 2, 3, 4, 5]

HTML form readonly SELECT tag/input

Below worked for me :

$('select[name=country]').attr("disabled", "disabled"); 

changing textbox border colour using javascript

I'm agree with Vicente Plata you should try using jQuery IMHO is the best javascript library. You can create a class in your CSS file and just do the following with jquery:

$('#fName').addClass('name_of_the_class'); 

and that's all, and of course you won't be worried about incompatibility of the browsers, that's jquery's team problem :D LOL

How do I "shake" an Android device within the Android emulator to bring up the dev menu to debug my React Native app

I was trying on a release build via adb install -r -d <app-release>.apk

Make sure you're running the debug build, then the menu will work via the shortcut or CLI.

What is the naming convention in Python for variable and function names?

Typically, one follow the conventions used in the language's standard library.

printf and long double

Yes -- for long double, you need to use %Lf (i.e., upper-case 'L').

Convert byte to string in Java

This is my version:

public String convertBytestoString(InputStream inputStream)
{
    int bytes;
    byte[] buffer = new byte[1024];

    bytes = inputStream.read(buffer);
    String stringData = new String(buffer,0,bytes);

    return stringData;

}

Android: Create spinner programmatically from array

In Kotlin language you can do it in this way:

val values = arrayOf(
    "cat",
    "dog",
    "chicken"
)

ArrayAdapter(
    this,
    android.R.layout.simple_spinner_item,
    values
).also {
    it.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item)
    spinner.adapter = it
}

C# password TextBox in a ASP.net website

@JohnHartsock: You can also write type="password". It's acceptable in aspx.

<asp:TextBox ID="txtBox" type="password" runat="server"/>

How to scroll UITableView to specific position

Simply single line of code:

self.tblViewMessages.scrollToRow(at: IndexPath.init(row: arrayChat.count-1, section: 0), at: .bottom, animated: isAnimeted)

A regex for version number parsing

^(?:(\d+)\.)?(?:(\d+)\.)?(\*|\d+)$

Perhaps a more concise one could be :

^(?:(\d+)\.){0,2}(\*|\d+)$

This can then be enhanced to 1.2.3.4.5.* or restricted exactly to X.Y.Z using * or {2} instead of {0,2}

What is a quick way to force CRLF in C# / .NET?

It depends on exactly what the requirements are. In particular, how do you want to handle "\r" on its own? Should that count as a line break or not? As an example, how should "a\n\rb" be treated? Is that one very odd line break, one "\n" break and then a rogue "\r", or two separate linebreaks? If "\r" and "\n" can both be linebreaks on their own, why should "\r\n" not be treated as two linebreaks?

Here's some code which I suspect is reasonably efficient.

using System;
using System.Text;

class LineBreaks
{    
    static void Main()
    {
        Test("a\nb");
        Test("a\nb\r\nc");
        Test("a\r\nb\r\nc");
        Test("a\rb\nc");
        Test("a\r");
        Test("a\n");
        Test("a\r\n");
    }

    static void Test(string input)
    {
        string normalized = NormalizeLineBreaks(input);
        string debug = normalized.Replace("\r", "\\r")
                                 .Replace("\n", "\\n");
        Console.WriteLine(debug);
    }

    static string NormalizeLineBreaks(string input)
    {
        // Allow 10% as a rough guess of how much the string may grow.
        // If we're wrong we'll either waste space or have extra copies -
        // it will still work
        StringBuilder builder = new StringBuilder((int) (input.Length * 1.1));

        bool lastWasCR = false;

        foreach (char c in input)
        {
            if (lastWasCR)
            {
                lastWasCR = false;
                if (c == '\n')
                {
                    continue; // Already written \r\n
                }
            }
            switch (c)
            {
                case '\r':
                    builder.Append("\r\n");
                    lastWasCR = true;
                    break;
                case '\n':
                    builder.Append("\r\n");
                    break;
                default:
                    builder.Append(c);
                    break;
            }
        }
        return builder.ToString();
    }
}

How to get rows count of internal table in abap?

You can use the following function:

 DESCRIBE TABLE <itab-Name> LINES <variable>

After the call, variable contains the number of rows of the internal table .

TOMCAT - HTTP Status 404

  1. Click on Window > Show view > Server or right click on the server in "Servers" view, select "Properties".
  2. In the "General" panel, click on the "Switch Location" button.
  3. The "Location: [workspace metadata]" should replace by something else.
  4. Open the Overview screen for the server by double clicking it.
  5. In the Server locations tab , select "Use Tomcat location".
  6. Save the configurations and restart the Server.

You may want to follow the steps above before starting the server. Because server location section goes grayed-unreachable.

server Locations in eclipse view

Adding git branch on the Bash command prompt

1- If you don't have bash-completion ... : sudo apt-get install bash-completion

2- Edit your .bashrc file and check (or add) :

if [ -f /etc/bash_completion ]; then
  . /etc/bash_completion
fi

3- ... before your prompt line : export PS1='$(__git_ps1) \w\$ '
(__git_ps1 will show your git branch)

4- do source .bashrc

EDIT :

Further readings : Don’t Reinvent the Wheel

Export table data from one SQL Server to another

Just for the kicks.

Since I wasnt able to create linked server and since just connecting to production server was not enough to use INSERT INTO i did the following:

  • created a backup of production server database
  • restored the database on my test server
  • executed the insert into statements

Its a backdoor solution, but since i had problems it worked for me.

Since i have created empty tables using SCRIPT TABLE AS / CREATE in order to transfer all the keys and indexes I couldnt use SELECT INTO. SELECT INTO only works if the tables do not exist on the destination location but it does not copy keys and indexes, so you have to do that manualy. The downside of using INSERT INTO statement is that you have to manualy provide with all the column names, plus it might give you some problems if some foreign key constraints fail.

Thanks to all anwsers, there are some great solutions but i have decided to accept marc_s anwser.

Correctly determine if date string is a valid date in that format

Give this a try:

$date = "2017-10-01";


function date_checker($input,$devider){
  $output = false;

  $input = explode($devider, $input);
  $year = $input[0];
  $month = $input[1];
  $day = $input[2];

  if (is_numeric($year) && is_numeric($month) && is_numeric($day)) {
    if (strlen($year) == 4 && strlen($month) == 2 && strlen($day) == 2) {
      $output = true;
    }
  }
  return $output;
}

if (date_checker($date, '-')) {
  echo "The function is working";
}else {
  echo "The function isNOT working";
}

Java: Most efficient method to iterate over all elements in a org.w3c.dom.Document?

I also stumbled over this problem recently. Here is my solution. I wanted to avoid recursion, so I used a while loop.

Because of the adds and removes in arbitrary places on the list, I went with the LinkedList implementation.

/* traverses tree starting with given node */
  private static List<Node> traverse(Node n)
  {
    return traverse(Arrays.asList(n));
  }

  /* traverses tree starting with given nodes */
  private static List<Node> traverse(List<Node> nodes)
  {
    List<Node> open = new LinkedList<Node>(nodes);
    List<Node> visited = new LinkedList<Node>();

    ListIterator<Node> it = open.listIterator();
    while (it.hasNext() || it.hasPrevious())
    {
      Node unvisited;
      if (it.hasNext())
        unvisited = it.next();
      else
        unvisited = it.previous();

      it.remove();

      List<Node> children = getChildren(unvisited);
      for (Node child : children)
        it.add(child);

      visited.add(unvisited);
    }

    return visited;
  }

  private static List<Node> getChildren(Node n)
  {
    List<Node> children = asList(n.getChildNodes());
    Iterator<Node> it = children.iterator();
    while (it.hasNext())
      if (it.next().getNodeType() != Node.ELEMENT_NODE)
        it.remove();
    return children;
  }

  private static List<Node> asList(NodeList nodes)
  {
    List<Node> list = new ArrayList<Node>(nodes.getLength());
    for (int i = 0, l = nodes.getLength(); i < l; i++)
      list.add(nodes.item(i));
    return list;
  }

Change border-bottom color using jquery?

$('#elementid').css('border-bottom', 'solid 1px red');

How to printf "unsigned long" in C?

Out of all the combinations you tried, %ld and %lu are the only ones which are valid printf format specifiers at all. %lu (long unsigned decimal), %lx or %lX (long hex with lowercase or uppercase letters), and %lo (long octal) are the only valid format specifiers for a variable of type unsigned long (of course you can add field width, precision, etc modifiers between the % and the l).

What is the hamburger menu icon called and the three vertical dots icon called?

Look at this photo, it says "Kebab Menu" is a correct answer:

enter image description here

per comment below, sourced from Luke Wroblewski: https://twitter.com/lukew/status/591296890030915585/photo/1

no match for ‘operator<<’ in ‘std::operator

Object is a collection of methods and variables.You can't print the variables in object by just cout operation . if you want to show the things inside the object you have to declare either a getter or a display text method in class.

ex

#include <iostream>

using namespace std;

class mystruct

{
private:
    int m_a;
    float m_b;

public:
    mystruct(int x, float y)
    {
            m_a = x;
            m_b = y;
    }
    public:
    void getm_aAndm_b()
    {
        cout<<m_a<<endl;
        cout<<m_b<<endl;
    }



};

int main()
{

    mystruct m = mystruct(5,3.14);

    cout << "my structure " << endl;
    m.getm_aAndm_b();
    return 0;

}

Not that this is just a one way of doing it

Escape Character in SQL Server

If you want to escape user input in a variable you can do like below within SQL

  Set @userinput = replace(@userinput,'''','''''')

The @userinput will be now escaped with an extra single quote for every occurance of a quote

SQL MAX of multiple columns?

enter image description hereAbove table is an employee salary table with salary1,salary2,salary3,salary4 as columns.Query below will return the max value out of four columns

select  
 (select Max(salval) from( values (max(salary1)),(max(salary2)),(max(salary3)),(max(Salary4)))alias(salval)) as largest_val
 from EmployeeSalary

Running above query will give output as largest_val(10001)

Logic of above query is as below:

select Max(salvalue) from(values (10001),(5098),(6070),(7500))alias(salvalue)

output will be 10001

When to catch java.lang.Error?

Never. You can never be sure that the application is able to execute the next line of code. If you get an OutOfMemoryError, you have no guarantee that you will be able to do anything reliably. Catch RuntimeException and checked Exceptions, but never Errors.

http://pmd.sourceforge.net/rules/strictexception.html

How do I combine two dataframes?

There's another solution for the case that you are working with big data and need to concatenate multiple datasets. concat can get performance-intensive, so if you don't want to create a new df each time, you can instead use a list comprehension:

frames = [ process_file(f) for f in dataset_files ]
result = pd.append(frames)

(as pointed out here in the docs at the bottom of the section):

Note: It is worth noting however, that concat (and therefore append) makes a full copy of the data, and that constantly reusing this function can create a significant performance hit. If you need to use the operation over several datasets, use a list comprehension.

Align items in a stack panel?

You can achieve this with a DockPanel:

<DockPanel Width="300">
    <TextBlock>Left</TextBlock>
    <Button HorizontalAlignment="Right">Right</Button>
</DockPanel>

The difference is that a StackPanel will arrange child elements into single line (either vertical or horizontally) whereas a DockPanel defines an area where you can arrange child elements either horizontally or vertically, relative to each other (the Dock property changes the position of an element relative to other elements within the same container. Alignment properties, such as HorizontalAlignment, change the position of an element relative to its parent element).

Update

As pointed out in the comments you can also use the FlowDirection property of a StackPanel. See @D_Bester's answer.

Are lists thread-safe?

I recently had this case where I needed to append to a list continuously in one thread, loop through the items and check if the item was ready, it was an AsyncResult in my case and remove it from the list only if it was ready. I could not find any examples that demonstrated my problem clearly Here is an example demonstrating adding to list in one thread continuously and removing from the same list in another thread continuously The flawed version runs easily on smaller numbers but keep the numbers big enough and run a few times and you will see the error

The FLAWED version

import threading
import time

# Change this number as you please, bigger numbers will get the error quickly
count = 1000
l = []

def add():
    for i in range(count):
        l.append(i)
        time.sleep(0.0001)

def remove():
    for i in range(count):
        l.remove(i)
        time.sleep(0.0001)


t1 = threading.Thread(target=add)
t2 = threading.Thread(target=remove)
t1.start()
t2.start()
t1.join()
t2.join()

print(l)

Output when ERROR

Exception in thread Thread-63:
Traceback (most recent call last):
  File "/Users/zup/.pyenv/versions/3.6.8/lib/python3.6/threading.py", line 916, in _bootstrap_inner
    self.run()
  File "/Users/zup/.pyenv/versions/3.6.8/lib/python3.6/threading.py", line 864, in run
    self._target(*self._args, **self._kwargs)
  File "<ipython-input-30-ecfbac1c776f>", line 13, in remove
    l.remove(i)
ValueError: list.remove(x): x not in list

Version that uses locks

import threading
import time
count = 1000
l = []
lock = threading.RLock()
def add():
    with lock:
        for i in range(count):
            l.append(i)
            time.sleep(0.0001)

def remove():
    with lock:
        for i in range(count):
            l.remove(i)
            time.sleep(0.0001)


t1 = threading.Thread(target=add)
t2 = threading.Thread(target=remove)
t1.start()
t2.start()
t1.join()
t2.join()

print(l)

Output

[] # Empty list

Conclusion

As mentioned in the earlier answers while the act of appending or popping elements from the list itself is thread safe, what is not thread safe is when you append in one thread and pop in another

Transparent color of Bootstrap-3 Navbar

  1. Go to http://px64.net/
  2. mess around with opacity, add your image or choose color.
  3. copy either html or css(css is easier) the site spits out.
  4. Select your element aka the navbar.

  5. .navbar{ background-image:url(link that the site provides); background-repeat:repeat;

  6. Enjoy.

What is the difference between signed and unsigned variables?

This may not be the exact definition but I'll give you an example: If you were to create a random number taking it from the system time, here using the unsigned variable is beneficial as there is large scope for random numbers as signed numbers give both positive and negative numbers. As the system time can't be negative we use unsigned variable(Only positive numbers) and we have more wide range of random numbers.

How to search for an element in a golang slice

There is no library function for that. You have to code by your own.

for _, value := range myconfig {
    if value.Key == "key1" {
        // logic
    }
}

Working code: https://play.golang.org/p/IJIhYWROP_

package main

import (
    "encoding/json"
    "fmt"
)

func main() {
    type Config struct {
        Key   string
        Value string
    }

    var respbody = []byte(`[
        {"Key":"Key1", "Value":"Value1"},
        {"Key":"Key2", "Value":"Value2"}
    ]`)

    var myconfig []Config

    err := json.Unmarshal(respbody, &myconfig)
    if err != nil {
        fmt.Println("error:", err)
    }

    fmt.Printf("%+v\n", myconfig)

    for _, v := range myconfig {
        if v.Key == "Key1" {
            fmt.Println("Value: ", v.Value)
        }
    }

}