Programs & Examples On #Labelled break

Why shouldn't `'` be used to escape single quotes?

" is on the official list of valid HTML 4 entities, but ' is not.

From C.16. The Named Character Reference ':

The named character reference ' (the apostrophe, U+0027) was introduced in XML 1.0 but does not appear in HTML. Authors should therefore use ' instead of ' to work as expected in HTML 4 user agents.

How can I install a .ipa file to my iPhone simulator

In Xcode 6+ and iOS8+ you can do the simple steps below

  1. Paste .app file on desktop.
  2. Open terminal and paste the commands below:

    cd desktop

    xcrun simctl install booted

  3. Open iPhone simulator and click on app and use

For versions below iOS 8, do the following simple steps.

Note: You'll want to make sure that your app is built for all architectures, the Simulator is x386 in the Build Settings and Build Active Architecture Only set to No.

  1. Path: Library->Application Support->iPhone Simulator->7.1 (or another version if you need it)->Applications
  2. Create a new folder with the name of the app
  3. Go inside the folder and place the .app file here.

Proper use of 'yield return'

And what about this?

public static IEnumerable<Product> GetAllProducts()
    using (AdventureWorksEntities db = new AdventureWorksEntities())
        var products = from product in db.Product
                       select product;

        return products.ToList();

I guess this is much cleaner. I do not have VS2008 at hand to check, though. In any case, if Products implements IEnumerable (as it seems to - it is used in a foreach statement), I'd return it directly.

How to do left join in Doctrine?

If you have an association on a property pointing to the user (let's say Credit\Entity\UserCreditHistory#user, picked from your example), then the syntax is quite simple:

public function getHistory($users) {
    $qb = $this->entityManager->createQueryBuilder();
        ->select('a', 'u')
        ->from('Credit\Entity\UserCreditHistory', 'a')
        ->leftJoin('a.user', 'u')
        ->where('u = :user')
        ->setParameter('user', $users)
        ->orderBy('a.created_at', 'DESC');

    return $qb->getQuery()->getResult();

Since you are applying a condition on the joined result here, using a LEFT JOIN or simply JOIN is the same.

If no association is available, then the query looks like following

public function getHistory($users) {
    $qb = $this->entityManager->createQueryBuilder();
        ->select('a', 'u')
        ->from('Credit\Entity\UserCreditHistory', 'a')
            'a.user ='
        ->where('u = :user')
        ->setParameter('user', $users)
        ->orderBy('a.created_at', 'DESC');

    return $qb->getQuery()->getResult();

This will produce a resultset that looks like following:

        0 => UserCreditHistory instance,
        1 => Userinstance,
        0 => UserCreditHistory instance,
        1 => Userinstance,
    // ...

When to use React setState callback

Sometimes we need a code block where we need to perform some operation right after setState where we are sure the state is being updated. That is where setState callback comes into play

For example, there was a scenario where I needed to enable a modal for 2 customers out of 20 customers, for the customers where we enabled it, there was a set of time taking API calls, so it looked like this

async componentDidMount() {
  const appConfig = getCustomerConfig();
  this.setState({enableModal: appConfig?.enableFeatures?.paymentModal }, async 
       //make some API call for data needed in poput

enableModal boolean was required in UI blocks in the render function as well, that's why I did setState here, otherwise, could've just checked condition once and either called API set or not.

Using braces with dynamic variable names in PHP

Try using {} instead of ():

${"file".$i} = file($filelist[$i]);

How do I get multiple subplots in matplotlib?

Go with the following if you really want to use a loop. Nobody has actually answered how to feed data in a loop:

def plot(data):
    fig = plt.figure(figsize=(100, 100))
    for idx, k in enumerate(data.keys(), 1):
        x, y = data[k].keys(), data[k].values
        plt.subplot(63, 10, idx), y)

"Items collection must be empty before using ItemsSource."

In my case, it was not using a DataTemplate for the ItemsControl.


<ItemsControl Width="243" ItemsSource="{Binding List, Mode=TwoWay}">
    <StackPanel Orientation="Horizontal">
        <TextBox Width="25" Margin="0,0,5,0" Text="{Binding Path=Property1}"/>
        <Label Content="{Binding Path=Property2}"/>


<ItemsControl Width="243" ItemsSource="{Binding List, Mode=TwoWay}">
            <StackPanel Orientation="Horizontal">
                <TextBox Width="25" Margin="0,0,5,0" Text="{Binding Path=Property1}"/>
                <Label Content="{Binding Path=Property2}"/>

List all liquibase sql types

This is a comprehensive list of all liquibase datatypes and how they are converted for different databases:

MySQLDatabase: BIT(1)
SQLiteDatabase: BOOLEAN
H2Database: BOOLEAN
PostgresDatabase: BOOLEAN
UnsupportedDatabase: BOOLEAN
MSSQLDatabase: [bit]
OracleDatabase: NUMBER(1)
HsqlDatabase: BOOLEAN
FirebirdDatabase: SMALLINT
DerbyDatabase: SMALLINT
InformixDatabase: BOOLEAN
SybaseDatabase: BIT
SybaseASADatabase: BIT

SQLiteDatabase: TINYINT
H2Database: TINYINT
PostgresDatabase: SMALLINT
UnsupportedDatabase: TINYINT
MSSQLDatabase: [tinyint]
OracleDatabase: NUMBER(3)
HsqlDatabase: TINYINT
FirebirdDatabase: SMALLINT
DerbyDatabase: SMALLINT
InformixDatabase: TINYINT
SybaseDatabase: TINYINT
SybaseASADatabase: TINYINT

MySQLDatabase: INT
SQLiteDatabase: INTEGER
H2Database: INT
PostgresDatabase: INT
UnsupportedDatabase: INT
DB2Database: INTEGER
MSSQLDatabase: [int]
OracleDatabase: INTEGER
HsqlDatabase: INT
FirebirdDatabase: INT
DerbyDatabase: INTEGER
InformixDatabase: INT
SybaseDatabase: INT
SybaseASADatabase: INT

PostgresDatabase: MEDIUMINT
UnsupportedDatabase: MEDIUMINT
MSSQLDatabase: [int]
OracleDatabase: MEDIUMINT
HsqlDatabase: MEDIUMINT
FirebirdDatabase: MEDIUMINT
DerbyDatabase: MEDIUMINT
InformixDatabase: MEDIUMINT
SybaseDatabase: MEDIUMINT
SybaseASADatabase: MEDIUMINT

SQLiteDatabase: BIGINT
H2Database: BIGINT
PostgresDatabase: BIGINT
UnsupportedDatabase: BIGINT
DB2Database: BIGINT
MSSQLDatabase: [bigint]
OracleDatabase: NUMBER(38, 0)
HsqlDatabase: BIGINT
FirebirdDatabase: BIGINT
DerbyDatabase: BIGINT
InformixDatabase: INT8
SybaseDatabase: BIGINT
SybaseASADatabase: BIGINT

MySQLDatabase: FLOAT
SQLiteDatabase: FLOAT
H2Database: FLOAT
PostgresDatabase: FLOAT
UnsupportedDatabase: FLOAT
DB2Database: FLOAT
MSSQLDatabase: [float](53)
OracleDatabase: FLOAT
HsqlDatabase: FLOAT
FirebirdDatabase: FLOAT
DerbyDatabase: FLOAT
InformixDatabase: FLOAT
SybaseDatabase: FLOAT
SybaseASADatabase: FLOAT

SQLiteDatabase: DOUBLE
H2Database: DOUBLE
PostgresDatabase: DOUBLE PRECISION
UnsupportedDatabase: DOUBLE
DB2Database: DOUBLE
MSSQLDatabase: [float](53)
OracleDatabase: FLOAT(24)
HsqlDatabase: DOUBLE
FirebirdDatabase: DOUBLE PRECISION
DerbyDatabase: DOUBLE
InformixDatabase: DOUBLE PRECISION
SybaseDatabase: DOUBLE
SybaseASADatabase: DOUBLE

SQLiteDatabase: DECIMAL
H2Database: DECIMAL
PostgresDatabase: DECIMAL
UnsupportedDatabase: DECIMAL
DB2Database: DECIMAL
MSSQLDatabase: [decimal](18, 0)
OracleDatabase: DECIMAL
HsqlDatabase: DECIMAL
FirebirdDatabase: DECIMAL
DerbyDatabase: DECIMAL
InformixDatabase: DECIMAL
SybaseDatabase: DECIMAL
SybaseASADatabase: DECIMAL

MySQLDatabase: numeric
SQLiteDatabase: NUMBER
H2Database: NUMBER
PostgresDatabase: numeric
UnsupportedDatabase: NUMBER
DB2Database: numeric
MSSQLDatabase: [numeric](18, 0)
OracleDatabase: NUMBER
HsqlDatabase: numeric
FirebirdDatabase: numeric
DerbyDatabase: numeric
InformixDatabase: numeric
SybaseDatabase: numeric
SybaseASADatabase: numeric

SQLiteDatabase: BLOB
H2Database: BLOB
PostgresDatabase: BYTEA
UnsupportedDatabase: BLOB
DB2Database: BLOB
MSSQLDatabase: [varbinary](MAX)
OracleDatabase: BLOB
HsqlDatabase: BLOB
FirebirdDatabase: BLOB
DerbyDatabase: BLOB
InformixDatabase: BLOB
SybaseDatabase: IMAGE
SybaseASADatabase: LONG BINARY

SQLiteDatabase: FUNCTION
H2Database: FUNCTION
PostgresDatabase: FUNCTION
UnsupportedDatabase: FUNCTION
MSSQLDatabase: [function]
OracleDatabase: FUNCTION
HsqlDatabase: FUNCTION
FirebirdDatabase: FUNCTION
DerbyDatabase: FUNCTION
InformixDatabase: FUNCTION
SybaseDatabase: FUNCTION
SybaseASADatabase: FUNCTION

SQLiteDatabase: UNKNOWN
H2Database: UNKNOWN
PostgresDatabase: UNKNOWN
UnsupportedDatabase: UNKNOWN
DB2Database: UNKNOWN
OracleDatabase: UNKNOWN
HsqlDatabase: UNKNOWN
FirebirdDatabase: UNKNOWN
DerbyDatabase: UNKNOWN
InformixDatabase: UNKNOWN
SybaseDatabase: UNKNOWN
SybaseASADatabase: UNKNOWN

MySQLDatabase: datetime
SQLiteDatabase: TEXT
UnsupportedDatabase: datetime
MSSQLDatabase: [datetime]
OracleDatabase: TIMESTAMP
HsqlDatabase: TIMESTAMP
FirebirdDatabase: TIMESTAMP
DerbyDatabase: TIMESTAMP
SybaseDatabase: datetime
SybaseASADatabase: datetime

MySQLDatabase: time
SQLiteDatabase: time
H2Database: time
UnsupportedDatabase: time
DB2Database: time
MSSQLDatabase: [time](7)
OracleDatabase: DATE
HsqlDatabase: time
FirebirdDatabase: time
DerbyDatabase: time
SybaseDatabase: time
SybaseASADatabase: time

MySQLDatabase: timestamp
SQLiteDatabase: TEXT
UnsupportedDatabase: timestamp
DB2Database: timestamp
MSSQLDatabase: [datetime]
OracleDatabase: TIMESTAMP
HsqlDatabase: TIMESTAMP
FirebirdDatabase: TIMESTAMP
DerbyDatabase: TIMESTAMP
SybaseDatabase: datetime
SybaseASADatabase: timestamp

MySQLDatabase: date
SQLiteDatabase: date
H2Database: date
PostgresDatabase: date
UnsupportedDatabase: date
DB2Database: date
MSSQLDatabase: [date]
OracleDatabase: date
HsqlDatabase: date
FirebirdDatabase: date
DerbyDatabase: date
InformixDatabase: date
SybaseDatabase: date
SybaseASADatabase: date

MySQLDatabase: CHAR
SQLiteDatabase: CHAR
H2Database: CHAR
PostgresDatabase: CHAR
UnsupportedDatabase: CHAR
DB2Database: CHAR
MSSQLDatabase: [char](1)
OracleDatabase: CHAR
HsqlDatabase: CHAR
FirebirdDatabase: CHAR
DerbyDatabase: CHAR
InformixDatabase: CHAR
SybaseDatabase: CHAR
SybaseASADatabase: CHAR

SQLiteDatabase: VARCHAR
H2Database: VARCHAR
PostgresDatabase: VARCHAR
UnsupportedDatabase: VARCHAR
DB2Database: VARCHAR
MSSQLDatabase: [varchar](1)
OracleDatabase: VARCHAR2
HsqlDatabase: VARCHAR
FirebirdDatabase: VARCHAR
DerbyDatabase: VARCHAR
InformixDatabase: VARCHAR
SybaseDatabase: VARCHAR
SybaseASADatabase: VARCHAR

MySQLDatabase: NCHAR
SQLiteDatabase: NCHAR
H2Database: NCHAR
PostgresDatabase: NCHAR
UnsupportedDatabase: NCHAR
DB2Database: NCHAR
MSSQLDatabase: [nchar](1)
OracleDatabase: NCHAR
HsqlDatabase: CHAR
FirebirdDatabase: NCHAR
DerbyDatabase: NCHAR
InformixDatabase: NCHAR
SybaseDatabase: NCHAR
SybaseASADatabase: NCHAR

SQLiteDatabase: NVARCHAR
H2Database: NVARCHAR
PostgresDatabase: VARCHAR
UnsupportedDatabase: NVARCHAR
MSSQLDatabase: [nvarchar](1)
OracleDatabase: NVARCHAR2
HsqlDatabase: VARCHAR
FirebirdDatabase: NVARCHAR
DerbyDatabase: VARCHAR
InformixDatabase: NVARCHAR
SybaseDatabase: NVARCHAR
SybaseASADatabase: NVARCHAR

SQLiteDatabase: TEXT
H2Database: CLOB
PostgresDatabase: TEXT
UnsupportedDatabase: CLOB
DB2Database: CLOB
MSSQLDatabase: [varchar](MAX)
OracleDatabase: CLOB
HsqlDatabase: CLOB
FirebirdDatabase: BLOB SUB_TYPE TEXT
DerbyDatabase: CLOB
InformixDatabase: CLOB
SybaseDatabase: TEXT

SQLiteDatabase: REAL
H2Database: DECIMAL
PostgresDatabase: DECIMAL
UnsupportedDatabase: DECIMAL
DB2Database: DECIMAL(19, 4)
MSSQLDatabase: [money]
OracleDatabase: NUMBER(15, 2)
HsqlDatabase: DECIMAL
FirebirdDatabase: DECIMAL(18, 4)
DerbyDatabase: DECIMAL
InformixDatabase: MONEY
SybaseDatabase: MONEY
SybaseASADatabase: MONEY

MySQLDatabase: char(36)
SQLiteDatabase: TEXT
H2Database: UUID
PostgresDatabase: UUID
UnsupportedDatabase: char(36)
DB2Database: char(36)
MSSQLDatabase: [uniqueidentifier]
OracleDatabase: RAW(16)
HsqlDatabase: char(36)
FirebirdDatabase: char(36)
DerbyDatabase: char(36)
InformixDatabase: char(36)

For reference, this is the groovy script I've used to generate this output:


import liquibase.database.core.*
import liquibase.datatype.core.*

def datatypes = [BooleanType,TinyIntType,IntType,MediumIntType,BigIntType,FloatType,DoubleType,DecimalType,NumberType,BlobType,DatabaseFunctionType,UnknownType,DateTimeType,TimeType,TimestampType,DateType,CharType,VarcharType,NCharType,NVarcharType,ClobType,CurrencyType,UUIDType]
def databases = [MySQLDatabase, SQLiteDatabase, H2Database, PostgresDatabase, UnsupportedDatabase, DB2Database, MSSQLDatabase, OracleDatabase, HsqlDatabase, FirebirdDatabase, DerbyDatabase, InformixDatabase, SybaseDatabase, SybaseASADatabase]
datatypes.each {
    def datatype = it.newInstance()
    databases.each { println "$it.simpleName: ${datatype.toDatabaseDataType(it.newInstance())}"}
    println ''

How do I profile memory usage in Python?

This one has been answered already here: Python memory profiler

Basically you do something like that (cited from Guppy-PE):

>>> from guppy import hpy; h=hpy()
>>> h.heap()
Partition of a set of 48477 objects. Total size = 3265516 bytes.
 Index  Count   %     Size   % Cumulative  % Kind (class / dict of class)
     0  25773  53  1612820  49   1612820  49 str
     1  11699  24   483960  15   2096780  64 tuple
     2    174   0   241584   7   2338364  72 dict of module
     3   3478   7   222592   7   2560956  78 types.CodeType
     4   3296   7   184576   6   2745532  84 function
     5    401   1   175112   5   2920644  89 dict of class
     6    108   0    81888   3   3002532  92 dict (no owner)
     7    114   0    79632   2   3082164  94 dict of type
     8    117   0    51336   2   3133500  96 type
     9    667   1    24012   1   3157512  97 __builtin__.wrapper_descriptor
<76 more rows. Type e.g. '_.more' to view.>
>>> h.iso(1,[],{})
Partition of a set of 3 objects. Total size = 176 bytes.
 Index  Count   %     Size   % Cumulative  % Kind (class / dict of class)
     0      1  33      136  77       136  77 dict (no owner)
     1      1  33       28  16       164  93 list
     2      1  33       12   7       176 100 int
>>> x=[]
>>> h.iso(x).sp
 0: h.Root.i0_modules['__main__'].__dict__['x']

How can I get form data with JavaScript/jQuery?

This will append all form fields to the JavaScript object "res":

var res = {};
$("#form input, #form select, #form textarea").each(function(i, obj) {
    res[] = $(obj).val();

'Linker command failed with exit code 1' when using Google Analytics via CocoaPods

Make sure you open the .xcworkspace file not the project file from xCode Project menu when working with pods. That should solve the issue with linking.

How to set child process' environment variable in Makefile

I only needed the environment variables locally to invoke my test command, here's an example setting multiple environment vars in a bash shell, and escaping the dollar sign in make.

SHELL := /bin/bash

.PHONY: test tests
test tests:
    PATH=./node_modules/.bin/:$$PATH \
    nodeunit tests/

How to update core-js to core-js@3 dependency?

With this

npm install --save core-js@^3

you now get the error

"core-js@<3 is no longer maintained and not recommended for usage due to the number of
issues. Please, upgrade your dependencies to the actual version of core-js@3"

so you might want to instead try

npm install --save core-js@3

if you're reading this post June 9 2020.

HTTP URL Address Encoding in Java

i use this

org.apache.commons.text.StringEscapeUtils.escapeHtml4("my text % & < >");

add this dependecy


Java HashMap: How to get a key and value by index?

I came across the same problem, read a couple of answers from different related questions and came up with my own class.

public class IndexableMap<K, V> extends HashMap<K, V> {

    private LinkedList<K> keyList = new LinkedList<>();

    public V put(K key, V value) {
        if (!keyList.contains(key))
        return super.put(key, value);

    public void putAll(Map<? extends K, ? extends V> m) {
        for (Entry<? extends K, ? extends V> entry : m.entrySet()) {
            put(entry.getKey(), entry.getValue());

    public void clear() {

    public List<K> getKeys() {
        return keyList;

    public int getKeyIndex(K key) {
        return keyList.indexOf(key);

    public K getKeyAt(int index) {
        if (keyList.size() > index)
            return keyList.get(index);
        return null;

    public V getValueAt(int index) {
        K key = getKeyAt(index);
        if (key != null)
            return get(key);
        return null;

Example (types are differing from OPs question just for clarity):

Map<String, Double> myMap = new IndexableMap<>();

List<String> keys = myMap.getKeys();
int keyIndex = myMap.getKeyIndex("keyString");
String key = myMap.getKeyAt(2);
Double value myMap.getValueAt(2);

Keep in mind that it does not override any of the complex methods, so you will need to do this on your own if you want to reliably access one of these.

Edit: I made a change to the putAll() method, because the old one had a rare chance to cause HashMap and LinkedList being in different states.

What is the preferred syntax for initializing a dict: curly brace literals {} or the dict() function?

I think the first option is better because you are going to access the values as a['a'] or a['another']. The keys in your dictionary are strings, and there is no reason to pretend they are not. To me the keyword syntax looks clever at first, but obscure at a second look. This only makes sense to me if you are working with __dict__, and the keywords are going to become attributes later, something like that.

Delete all files in directory (but not directory) - one liner solution

package com;
public class Delete {
    public static void main(String[] args) {

        String files; 
        File file = new File("D:\\del\\yc\\gh");
        File[] listOfFiles = file.listFiles(); 
        for (int i = 0; i < listOfFiles.length; i++) 
            if (listOfFiles[i].isFile()) 
                files = listOfFiles[i].getName();
                    boolean issuccess=new File(listOfFiles[i].toString()).delete();
                    System.err.println("Deletion Success "+issuccess);

If you want to delete all files remove


statement it will work.

Difference between UTF-8 and UTF-16?

This is unrelated to UTF-8/16 (in general, although it does convert to UTF16 and the BE/LE part can be set w/ a single line), yet below is the fastest way to convert String to byte[]. For instance: good exactly for the case provided (hash code). String.getBytes(enc) is relatively slow.

static byte[] toBytes(String s){
        byte[] b=new byte[s.length()*2];
        return b;

100% width Twitter Bootstrap 3 template

In BOOTSTRAP 4 you can use

<div class="row m-0">
my fullwidth div

... if you just use a .row without the .m-0 as a top level div, you will have unwanted margin, which makes the page wider than the browser window and cause a horizontal scrollbar.

How to find the day, month and year with moment.js

If you are looking for answer in string values , try this

var check = moment('date/utc format');
day = check.format('dddd') // => ('Monday' , 'Tuesday' ----)
month = check.format('MMMM') // => ('January','February.....)
year = check.format('YYYY') // => ('2012','2013' ...)  

ALTER COLUMN in sqlite

While it is true that the is no ALTER COLUMN, if you only want to rename the column, drop the NOT NULL constraint, or change the data type, you can use the following set of dangerous commands:

PRAGMA writable_schema = 1;
PRAGMA writable_schema = 0;

You will need to either close and reopen your connection or vacuum the database to reload the changes into the schema.

For example:

Y:\> **sqlite3 booktest**  
SQLite version 3.7.4  
Enter ".help" for instructions  
Enter SQL statements terminated with a ";"  
sqlite> **create table BOOKS ( title TEXT NOT NULL, publication_date TEXT NOT 
sqlite> **insert into BOOKS VALUES ("NULLTEST",null);**  
Error: BOOKS.publication_date may not be NULL  
sqlite> **PRAGMA writable_schema = 1;**  
NULL, publication_date TEXT)' WHERE NAME = 'BOOKS';**  
sqlite> **PRAGMA writable_schema = 0;**  
sqlite> **.q**  

Y:\> **sqlite3 booktest**  
SQLite version 3.7.4  
Enter ".help" for instructions  
Enter SQL statements terminated with a ";"  
sqlite> **insert into BOOKS VALUES ("NULLTEST",null);**  
sqlite> **.q**  


pragma writable_schema
When this pragma is on, the SQLITE_MASTER tables in which database can be changed using ordinary UPDATE, INSERT, and DELETE statements. Warning: misuse of this pragma can easily result in a corrupt database file.

[alter table](From
SQLite supports a limited subset of ALTER TABLE. The ALTER TABLE command in SQLite allows the user to rename a table or to add a new column to an existing table. It is not possible to rename a column, remove a column, or add or remove constraints from a table.


How to add new column to MYSQL table?

You should look into normalizing your database to avoid creating columns at runtime.

Make 3 tables:

  1. assessment
  2. question
  3. assessment_question (columns assessmentId, questionId)

Put questions and assessments in their respective tables and link them together through assessment_question using foreign keys.

Get connection status on client

You can check the socket.connected property:

var socket = io.connect();
console.log('check 1', socket.connected);
socket.on('connect', function() {
  console.log('check 2', socket.connected);

It's updated dynamically, if the connection is lost it'll be set to false until the client picks up the connection again. So easy to check for with setInterval or something like that.

Another solution would be to catch disconnect events and track the status yourself.

How do I remove the height style from a DIV using jQuery?

maybe something like

$('div#someDiv').css("height", "auto");

Fixed position but relative to container

Short answer: no. (It is now possible with CSS transform. See the edit below)

Long answer: The problem with using "fixed" positioning is that it takes the element out of flow. thus it can't be re-positioned relative to its parent because it's as if it didn't have one. If, however, the container is of a fixed, known width, you can use something like:

#fixedContainer {
  position: fixed;
  width: 600px;
  height: 200px;
  left: 50%;
  top: 0%;
  margin-left: -300px; /*half the width*/

Edit (03/2015):

This is outdated information. It is now possible to center content of an dynamic size (horizontally and vertically) with the help of the magic of CSS3 transform. The same principle applies, but instead of using margin to offset your container, you can use translateX(-50%). This doesn't work with the above margin trick because you don't know how much to offset it unless the width is fixed and you can't use relative values (like 50%) because it will be relative to the parent and not the element it's applied to. transform behaves differently. Its values are relative to the element they are applied to. Thus, 50% for transform means half the width of the element, while 50% for margin is half of the parent's width. This is an IE9+ solution

Using similar code to the above example, I recreated the same scenario using completely dynamic width and height:

.fixedContainer {
    position: fixed;
    padding: 2em;
    left: 50%;
    top: 0%;
    transform: translateX(-50%);

If you want it to be centered, you can do that too:

.fixedContainer {
    position: fixed;
    padding: 2em;
    left: 50%;
    top: 50%;
    transform: translate(-50%, -50%);


jsFiddle: Centered horizontally only
jsFiddle: Centered both horizontally and vertically
Original credit goes to user aaronk6 for pointing it out to me in this answer

LaTeX Optional Arguments

All of the above show hard it can be to make a nice, flexible (or forbid an overloaded) function in LaTeX!!! (that TeX code looks like greek to me)

well, just to add my recent (albeit not as flexible) development, here's what I've recently used in my thesis doc, with

\usepackage{ifthen}  % provides conditonals...

Start the command, with the "optional" command set blank by default:

\newcommand {\figHoriz} [4] []  {

I then have the macro set a temporary variable, \temp{}, differently depending on whether or not the optional argument is blank. This could be extended to any passed argument.

\ifthenelse { \equal {#1} {} }  %if short caption not specified, use long caption (no slant)
    { \def\temp {\caption[#4]{\textsl{#4}}} }   % if #1 == blank
    { \def\temp {\caption[#1]{\textsl{#4}}} }   % else (not blank)

Then I run the macro using the \temp{} variable for the two cases. (Here it just sets the short-caption to equal the long caption if it wasn't specified by the user).

        \includegraphics[width=350 pt]{#3}
        \temp   %see above for caption etc.

In this case I only check for the single, "optional" argument that \newcommand{} provides. If you were to set it up for, say, 3 "optional" args, you'd still have to send the 3 blank args... eg.

\MyCommand {first arg} {} {} {}

which is pretty silly, I know, but that's about as far as I'm going to go with LaTeX - it's just not that sensical once I start looking at TeX code... I do like Mr. Robertson's xparse method though, perhaps I'll try it...

How to parse an RSS feed using JavaScript?

I was so exasperated by many misleading articles and answers that I wrote my own RSS reader:

You can use AJAX requests to fetch the RSS files but it will work if and only if you use a CORS proxy. I'll try to write my own CORS proxy to give you a more robust solution. In the meantime, it works, I deployed it on my server under Debian Linux.

My solution doesn't use JQuery, I use only plain Javascript standard APIs with no third party libraries and it's supposed to work even with Microsoft Internet Explorer 11.

Referencing a string in a string array resource with xml

Another way of doing it is defining a resources array in strings.xml like below.

<?xml version="1.0" encoding="utf-8"?> <!DOCTYPE resources [
    <!ENTITY supportDefaultSelection "Choose your issue">
    <!ENTITY issueOption1 "Support">
    <!ENTITY issueOption2 "Feedback">
    <!ENTITY issueOption3 "Help">

and then defining a string array using the above resources

<string-array name="support_issues_array">

You could refer the same string into other xmls too keeping DRY intact. The advantage I see is, with a single value change it would effect all the references in the code.

How to format a floating number to fixed width in Python

See Python 3.x format string syntax:

IDLE 3.5.1   
numbers = ['23.23', '.1233', '1', '4.223', '9887.2']

for x in numbers:  
    print('{0: >#016.4f}'. format(float(x)))  


How to get list of dates between two dates in mysql select query


select * from 
(select adddate('1970-01-01',t4.i*10000 + t3.i*1000 + t2.i*100 + t1.i*10 + t0.i) selected_date from
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t0,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t1,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t2,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t3,
 (select 0 i union select 1 union select 2 union select 3 union select 4 union select 5 union select 6 union select 7 union select 8 union select 9) t4) v
where selected_date between '2012-02-10' and '2012-02-15'

-for date ranges up to nearly 300 years in the future.

[Corrected following a suggested edit by UrvishAtSynapse.]

How to show what a commit did?


git show <commit>


To show what a commit did with stats:

git show <commit> --stat


To show commit log with differences introduced for each commit in a range:

git log -p <commit1> <commit2>

What is <commit>?

Each commit has a unique id we reference here as <commit>. The unique id is an SHA-1 hash – a checksum of the content you’re storing plus a header. #TMI

If you don't know your <commit>:

  1. git log to view the commit history

  2. Find the commit you care about.

Is it possible to set UIView border properties from interface builder?

Storyboard doesn't work for me all the time even after trying all the solution here

So it is always perfect answer is using the code, Just create IBOutlet instance of the UIView and add the properties

Short answer :

layer.cornerRadius = 10
layer.borderWidth = 1
layer.borderColor =

Long answer :

Rounded Corners of UIView/UIButton etc

customUIView.layer.cornerRadius = 10

Border Thickness

pcustomUIView.layer.borderWidth = 2

Border Color

customUIView.layer.borderColor =

Send data from activity to fragment in Android

Also You can access activity data from fragment:


public class MyActivity extends Activity {

    private String myString = "hello";

    protected void onCreate(Bundle savedInstanceState) {

    public String getMyData() {
        return myString;


public class MyFragment extends Fragment {

    public View onCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState) {

        MyActivity activity = (MyActivity) getActivity();
        String myDataFromActivity = activity.getMyData();
        return view;

Maximum packet size for a TCP connection

Generally, this will be dependent on the interface the connection is using. You can probably use an ioctl() to get the MTU, and if it is ethernet, you can usually get the maximum packet size by subtracting the size of the hardware header from that, which is 14 for ethernet with no VLAN.

This is only the case if the MTU is at least that large across the network. TCP may use path MTU discovery to reduce your effective MTU.

The question is, why do you care?

How to get the excel file name / path in VBA

this is a simple alternative that gives all responses, Fullname, Path, filename.

Dim FilePath, FileOnly, PathOnly As String

FilePath = ThisWorkbook.FullName
FileOnly = ThisWorkbook.Name
PathOnly = Left(FilePath, Len(FilePath) - Len(FileOnly))

Common elements comparison between 2 lists

use set intersections, set(list1) & set(list2)

>>> def common_elements(list1, list2):
...     return list(set(list1) & set(list2))
>>> common_elements([1,2,3,4,5,6], [3,5,7,9])
[3, 5]
>>> common_elements(['this','this','n','that'],['this','not','that','that'])
['this', 'that']

Note that result list could be different order with original list.

Perform .join on value in array of objects

not sure, but all this answers tho they work but are not optiomal since the are performing two scans and you can perform this in a single scan. Even though O(2n) is considered O(n) is always better to have a true O(n).

const Join = (arr, separator, prop) => {
    let combined = '';
    for (var i = 0; i < arr.length; i++) {
        combined = `${combined}${arr[i][prop]}`;
        if (i + 1 < arr.length)
            combined = `${combined}${separator} `;
    return combined;

This might look like old school, but allows me to do thig like this:

skuCombined = Join(option.SKUs, ',', 'SkuNum');

Extract year from date

For some time now, you can also only rely on the data.table package and its IDate class plus associated functions (Check ?as.IDate()). So, no need to additionally install lubridate.


a <- c("01/01/2009", "01/01/2010" , "01/01/2011")
year(as.IDate(a, '%d/%m/%Y')) # all data.table functions

Logging in Scala

Using slf4j and a wrapper is nice but the use of it's built in interpolation breaks down when you have more than two values to interpolate, since then you need to create an Array of values to interpolate.

A more Scala like solution is to use a thunk or cluster to delay the concatenation of the error message. A good example of this is Lift's logger

Log.scala Slf4jLog.scala

Which looks like this:

class Log4JLogger(val logger: Logger) extends LiftLogger {
  override def trace(msg: => AnyRef) = if (isTraceEnabled) logger.trace(msg)

Note that msg is a call-by-name and won't be evaluated unless isTraceEnabled is true so there's no cost in generating a nice message string. This works around the slf4j's interpolation mechanism which requires parsing the error message. With this model, you can interpolate any number of values into the error message.

If you have a separate trait that mixes this Log4JLogger into your class, then you can do

trace("The foobar from " + a + " doesn't match the foobar from " +
      b + " and you should reset the baz from " + c")

instead of

info("The foobar from {0} doesn't match the foobar from {1} and you should reset the baz from {c},
     Array(a, b, c))

How to destroy an object?

I would go with unset because it might give the garbage collector a better hint so that the memory can be available again sooner. Be careful that any things the object points to either have other references or get unset first or you really will have to wait on the garbage collector since there would then be no handles to them.

pandas DataFrame: replace nan values with average of columns

# To read data from csv file
Dataset = pd.read_csv('Data.csv')

X = Dataset.iloc[:, :-1].values

# To calculate mean use imputer class
from sklearn.impute import SimpleImputer
imputer = SimpleImputer(missing_values=np.nan, strategy='mean')
imputer =[:, 1:3])
X[:, 1:3] = imputer.transform(X[:, 1:3])

How to center a component in Material-UI and make it responsive?

The @Nadun's version did not work for me, sizing wasn't working well. Removed the direction="column" or changing it to row, helps with building vertical login forms with responsive sizing.

  style={{ minHeight: "100vh" }}
  <Grid item xs={6}></Grid>

How do I specify "close existing connections" in sql script

I know it's too late but may be its helps some one. on using this take your database offline


The service cannot be started, either because it is disabled or because it has no enabled devices associated with it

This error can occur on anything that requires elevated privileges in Windows.

It happens when the "Application Information" service is disabled in Windows services. There are a few viruses that use this as an attack vector to prevent people from removing the virus. It also prevents people from installing software to remove viruses.

The normal way to fix this would be to run services.msc, or to go into Administrative Tools and run "Services". However, you will not be able to do that if the "Application Information" service is disabled.

Instead, reboot your computer into Safe Mode (reboot and press F8 until the Windows boot menu appears, select Safe Mode with Networking). Then run services.msc and look for services that are designated as "Disabled" in the Startup Type column. Change these "Disabled" services to "Automatic".

Make sure the "Application Information" service is set to a Startup Type of "Automatic".

When you are done enabling your services, click Ok at the bottom of the tool and reboot your computer back into normal mode. The problem should be resolved when Windows reboots.

How to check if curl is enabled or disabled


// Script to test if the CURL extension is installed on this server

// Define function to test
function _is_curl_installed() {
    if  (in_array  ('curl', get_loaded_extensions())) {
        return true;
    else {
        return false;

// Ouput text to user based on test
if (_is_curl_installed()) {
  echo "cURL is <span style=\"color:blue\">installed</span> on this server";
} else {
  echo "cURL is NOT <span style=\"color:red\">installed</span> on this server";

or a simple one -


Just search for curl

source -

get launchable activity name of package from adb

#launch app by package name
adb shell monkey -p ${package_name} -c android.intent.category.LAUNCHER 1;
sleep 1;
#get Activity name
adb shell logcat -d | grep 'START u0' | tail -n 1 | sed 's/.*cmp=\(.*\)} .*/\1/g'


How to Create an excel dropdown list that displays text with a numeric hidden value

There are two types of drop down lists available (I am not sure since which version).

ActiveX Drop Down
You can set the column widths, so your hidden column can be set to 0.

Form Drop Down
You could set the drop down range to a hidden sheet and reference the cell adjacent to the selected item. This would also work with the ActiveX type control.

How can I force WebKit to redraw/repaint to propagate style changes?

Since the display + offset trigger didn't work for me, I found a solution here:

i.e. = 'scale(1)';

Selecting default item from Combobox C#

You can set using SelectedIndex

comboBox1.SelectedIndex= 1;



comboBox1.SelectedItem = "your value"; // 

The latter won't throw an exception if the value is not available in the combobox


If the value to be selected is not specific then you would be better off with this

comboBox1.SelectedIndex = comboBox1.Items.Count - 1;

How to make function decorators and chain them together?

Decorate functions with different number of arguments:

def frame_tests(fn):
    def wrapper(*args):
        print "\nStart: %s" %(fn.__name__)
        print "End: %s\n" %(fn.__name__)
    return wrapper

def test_fn1():
    print "This is only a test!"

def test_fn2(s1):
    print "This is only a test! %s" %(s1)

def test_fn3(s1, s2):
    print "This is only a test! %s %s" %(s1, s2)

if __name__ == "__main__":
    test_fn3('OK!', 'Just a test!')


Start: test_fn1  
This is only a test!  
End: test_fn1  
Start: test_fn2  
This is only a test! OK!  
End: test_fn2  
Start: test_fn3  
This is only a test! OK! Just a test!  
End: test_fn3  

Passing data to components in vue.js

I think the issue is here:

<template id="newtemp" :name ="{{}}">

When you prefix the prop with : you are indicating to Vue that it is a variable, not a string. So you don't need the {{}} around Try:

<template id="newtemp" :name ="">


The above is true, but the bigger issue here is that when you change the URL and go to a new route, the original component disappears. In order to have the second component edit the parent data, the second component would need to be a child component of the first one, or just a part of the same component.

Pandas/Python: Set value of one column based on value in another column

Note the tilda that reverses the selection. It uses pandas methods (i.e. is faster than if/else).

df.loc[(df['c1'] == 'Value'), 'c2'] = 10
df.loc[~(df['c1'] == 'Value'), 'c2'] = df['c3']

How to match, but not capture, part of a regex?

Update: Thanks to Germán Rodríguez Herrera!

In javascript try: /123-(apple(?=-)|banana(?=-)|(?!-))-?456/

Remember that the result is in group 1

Debuggex Demo

Why don't Java's +=, -=, *=, /= compound assignment operators require casting?

Subtle point here...

There is an implicit typecast for i+j when j is a double and i is an int. Java ALWAYS converts an integer into a double when there is an operation between them.

To clarify i+=j where i is an integer and j is a double can be described as

i = <int>(<double>i + j)

See: this description of implicit casting

You might want to typecast j to (int) in this case for clarity.

Best way to get identity of inserted row?

@@IDENTITY is the last identity inserted using the current SQL Connection. This is a good value to return from an insert stored procedure, where you just need the identity inserted for your new record, and don't care if more rows were added afterward.

SCOPE_IDENTITY is the last identity inserted using the current SQL Connection, and in the current scope -- that is, if there was a second IDENTITY inserted based on a trigger after your insert, it would not be reflected in SCOPE_IDENTITY, only the insert you performed. Frankly, I have never had a reason to use this.

IDENT_CURRENT(tablename) is the last identity inserted regardless of connection or scope. You could use this if you want to get the current IDENTITY value for a table that you have not inserted a record into.

Any reason not to use '+' to concatenate two strings?

Plus operator is perfectly fine solution to concatenate two Python strings. But if you keep adding more than two strings (n > 25) , you might want to think something else.

''.join([a, b, c]) trick is a performance optimization.

Git - Won't add files?

I recently experienced this issue on my computer running Windows 7. I am using the git command window interface. The solution was to be very careful about the case sensitivity of the file and directory names when doing the git add. Although git would not complain when the case did not exactly match the case of the Windows file system file and directory names it also would not add the files. There would be nothing to commit. Once I typed the file names with the exactly correct case they would be added and listed under the changes to be committed as I intended.

Programmatically scroll to a specific position in an Android ListView

Handling listView scrolling using UP/ Down using.button

If someone is interested in handling listView one row up/down using button. then.

public View.OnClickListener onChk = new View.OnClickListener() {
             public void onClick(View v) {

                 int index = list.getFirstVisiblePosition();
                 getListView().smoothScrollToPosition(index+1); // For increment. 


Append integer to beginning of list in Python

>>>array = [1,2,3,4,5,6]
[7, 1, 2, 3, 4, 5, 6]

How it works:

array.insert(index, value)

Insert an item at a given position. The first argument is the index of the element before which to insert, so array.insert(0, x) inserts at the front of the list, and array.insert(len(array), x) is equivalent to array.append(x).Negative values are treated as being relative to the end of the array.

VMware Workstation and Device/Credential Guard are not compatible

If you are someone who maintains an open customized "Run as administrator" command prompt or powershell command line window at all the times you can optionally setup the following aliases / macros to simplify executing the commands mentioned by @gue22 for simply disabling hyper-v hypervisor when needing to use vmware player or workstation and then enabling it again when done.

doskey hpvEnb = choice /c:yn /cs /d n /t 30 /m "Are you running from elevated command prompt" ^& if not errorlevel 2 ( bcdedit /set hypervisorlaunchtype auto ^& echo.^&echo now reboot to enable hyper-v hypervisor )
doskey hpvDis = choice /c:yn /cs /d n /t 30 /m "Are you running from elevated command prompt" ^& if not errorlevel 2 ( bcdedit /set hypervisorlaunchtype off ^& echo.^&echo now reboot to disable hyper-v hypervisor )
doskey bcdL = bcdedit /enum ^& echo.^&echo now see boot configuration data store {current} boot loader settings

With the above in place you just type "hpvenb" [ hypervisor enabled at boot ], "hpvdis" [ hypervisor disabled at boot ] and "bcdl" [ boot configuration devices list ] commands to execute the on, off, list commands.

What are -moz- and -webkit-?

These are the vendor-prefixed properties offered by the relevant rendering engines (-webkit for Chrome, Safari; -moz for Firefox, -o for Opera, -ms for Internet Explorer). Typically they're used to implement new, or proprietary CSS features, prior to final clarification/definition by the W3.

This allows properties to be set specific to each individual browser/rendering engine in order for inconsistencies between implementations to be safely accounted for. The prefixes will, over time, be removed (at least in theory) as the unprefixed, the final version, of the property is implemented in that browser.

To that end it's usually considered good practice to specify the vendor-prefixed version first and then the non-prefixed version, in order that the non-prefixed property will override the vendor-prefixed property-settings once it's implemented; for example:

.elementClass {
    -moz-border-radius: 2em;
    -ms-border-radius: 2em;
    -o-border-radius: 2em;
    -webkit-border-radius: 2em;
    border-radius: 2em;

Specifically, to address the CSS in your question, the lines you quote:

-webkit-column-count: 3;
-webkit-column-gap: 10px;
-webkit-column-fill: auto;
-moz-column-count: 3;
-moz-column-gap: 10px;
-moz-column-fill: auto;

Specify the column-count, column-gap and column-fill properties for Webkit browsers and Firefox.


Javascript to stop HTML5 video playback on modal window close

I'm not sure whether ZohoGorganzola's solution is correct; however, you may want to try getting at the element directly rather than trying to invoke a method on the jQuery collection, so instead of




git add remote branch

You can check if you got your remote setup right and have the proper permissions with

git ls-remote origin

if you called your remote "origin". If you get an error you probably don't have your security set up correctly such as uploading your public key to github for example. If things are setup correctly, you will get a list of the remote references. Now

git fetch origin

will work barring any other issues like an unplugged network cable.

Once you have that done, you can get any branch you want that the above command listed with

git checkout some-branch

this will create a local branch of the same name as the remote branch and check it out.

Why should we typedef a struct so often in C?

In 'C' programming language the keyword 'typedef' is used to declare a new name for some object(struct, array, function..enum type). For example, I will use a 'struct-s'. In 'C' we often declare a 'struct' outside of the 'main' function. For example:

struct complex{ int real_part, img_part }COMPLEX;


 struct KOMPLEKS number; // number type is now a struct type
 number.real_part = 3;
 number.img_part = -1;
 printf("Number: %d.%d i \n",number.real_part, number.img_part);


Each time I decide to use a struct type I will need this keyword 'struct 'something' 'name'.'typedef' will simply rename that type and I can use that new name in my program every time I want. So our code will be:

typedef struct complex{int real_part, img_part; }COMPLEX;
//now COMPLEX is the new name for this structure and if I want to use it without
// a keyword like in the first example 'struct complex number'.


COMPLEX number; // number is now the same type as in the first example
number.real_part = 1;
number.img)part = 5;
printf("%d %d \n", number.real_part, number.img_part);


If you have some local object(struct, array, valuable) that will be used in your entire program you can simply give it a name using a 'typedef'.

What does random.sample() method in python do?

random.sample() also works on text


> text = open("textfile.txt").read() 

> random.sample(text, 5)

> ['f', 's', 'y', 'v', '\n']

\n is also seen as a character so that can also be returned

you could use random.sample() to return random words from a text file if you first use the split method


> words = text.split()

> random.sample(words, 5)

> ['the', 'and', 'a', 'her', 'of']

Request Permission for Camera and Library in iOS 10 - Info.plist

File: Info.plist

For Camera:

<string>You can take photos to document your job.</string>

For Photo Library, you will want this one to allow app user to browse the photo library.

<string>You can select photos to attach to reports.</string>

How to call window.alert("message"); from C#?

I'm not sure if I understand but I'm guessing that you're trying to show a MessageBox from ASP.Net?

If so, this code project article might be helpful: Simple MessageBox functionality in ASP.NET

Android Gradle plugin 0.7.0: "duplicate files during packaging of APK"

I noticed this commit comment in AOSP, the solution will be to exclude some files using DSL. Probably when 0.7.1 is released.

commit e7669b24c1f23ba457fdee614ef7161b33feee69
Author: Xavier Ducrohet <--->
Date:   Thu Dec 19 10:21:04 2013 -0800

    Add DSL to exclude some files from packaging.

    This only applies to files coming from jar dependencies.
    The DSL is:

    android {
      packagingOptions {
        exclude 'META-INF/LICENSE.txt'

How do I return an int from EditText? (Android)

You can do this in 2 steps:

1: Change the input type(In your EditText field) in the layout file to android:inputType="number"

2: Use int a = Integer.parseInt(yourEditTextObject.getText().toString());

Is it a good practice to use an empty URL for a HTML form's action attribute? (action="")

The best thing you can do is leave out the action attribute altogether. If you leave it out, the form will be submitted to the document's address, i.e. the same page.

It is also possible to leave it empty, and any browser implementing HTML's form submission algorithm will treat it as equivalent to the document's address, which it does mainly because that's how browsers currently work:

8. Let action be the submitter element's action.

9. If action is the empty string, let action be the document's address.

Note: This step is a willful violation of RFC 3986, which would require base URL processing here. This violation is motivated by a desire for compatibility with legacy content. [RFC3986]

This definitely works in all current browsers, but may not work as expected in some older browsers ("browsers do weird things with an empty action="" attribute"), which is why the spec strongly discourages authors from leaving it empty:

The action and formaction content attributes, if specified, must have a value that is a valid non-empty URL potentially surrounded by spaces.

Using CRON jobs to visit url?

* * * * * wget -O - >/dev/null 2>&1

That should work for you. Just have a wget script that loads the page.

Using -O - means that the output of the web request will be sent to STDOUT (standard output)

by adding >/dev/null we instruct standard output to be redirect to a black hole. by adding 2>&1 we instruct STDERR (errors) to also be sent to STDOUT, and thus all output will be sent to a blackhole. (so it will load the website, but never write a file anywhere)

curl usage to get header

You need to add the -i flag to the first command, to include the HTTP header in the output. This is required to print headers.

curl -X HEAD -i

More here: cannot open shared object file

I'm having a similar issue.

I found

conda install pyodbc

is wrong!

when I use

apt-get install python-pyodbc

I solved this problem?

File to byte[] in Java

If you want to read bytes into a pre-allocated byte buffer, this answer may help.

Your first guess would probably be to use InputStream read(byte[]). However, this method has a flaw that makes it unreasonably hard to use: there is no guarantee that the array will actually be completely filled, even if no EOF is encountered.

Instead, take a look at DataInputStream readFully(byte[]). This is a wrapper for input streams, and does not have the above mentioned issue. Additionally, this method throws when EOF is encountered. Much nicer.

Correct way to pause a Python program

I have had a similar question and I was using signal:

import signal

def signal_handler(signal_number, frame):
    print "Proceed ..."

signal.signal(signal.SIGINT, signal_handler)

So you register a handler for the signal SIGINT and pause waiting for any signal. Now from outside your program (e.g. in bash), you can run kill -2 <python_pid>, which will send signal 2 (i.e. SIGINT) to your python program. Your program will call your registered handler and proceed running.

Execute cmd command from VBScript

Can also invoke oShell.Exec in order to be able to read STDIN/STDOUT/STDERR responses. Perfect for error checking which it seems you're doing with your sanity .BAT.

LINQ Join with Multiple Conditions in On Clause

You can't do it like that. The join clause (and the Join() extension method) supports only equijoins. That's also the reason, why it uses equals and not ==. And even if you could do something like that, it wouldn't work, because join is an inner join, not outer join.

How to add items to a spinner in Android?

Add this code after updating the list


The ArrayAdapter<String> variable name is dataAdapter, and the List variable name is keys.

  • dataAdapter.addAll(keys);
  • dataAdapter.notifyDataSetChanged();

Android layout replacing a view with another view on run time

private void replaceView(View oldV,View newV){
        ViewGroup par = (ViewGroup)oldV.getParent();
        if(par == null){return;}
        int i1 = par.indexOfChild(oldV);

MySQL select query with multiple conditions

Lets suppose there is a table with following describe command for table (hello)- name char(100), id integer, count integer, city char(100).

we have following basic commands for MySQL -

select * from hello;
select name, city from hello;

select name from hello where id = 8;
select id from hello where name = 'GAURAV';

now lets see multiple where condition -

select name from hello where id = 3 or id = 4 or id = 8 or id = 22;

select name from hello where id =3 and count = 3 city = 'Delhi';

This is how we can use multiple where commands in MySQL.

How to do a less than or equal to filter in Django queryset?

Less than or equal:


Greater than or equal:


Likewise, lt for less than and gt for greater than. You can find them all in the documentation.

How to unapply a migration in ASP.NET Core with EF Core



> dotnet ef database update <previous-migration-name>

Package Manager Console

PM> Update-Database <previous-migration-name>


PM> Update-Database MyInitialMigration

Then try to remove last migration.

Removing migration without database update doesn't work because you applied changes to database.

If using PMC, Try: PM> update-database 0 This will wipe the database and allow you to remove the Migration Snapshot on your Solution

Javascript ES6/ES5 find in array and change

Whereas most of the existing answers are great, I would like to include an answer using a traditional for loop, which should also be considered here. The OP requests an answer which is ES5/ES6 compatible, and the traditional for loop applies :)

The problem with using array functions in this scenario, is that they don't mutate objects, but in this case, mutation is a requirement. The performance gain of using a traditional for loop is just a (huge) bonus.

const findThis = 2;
const items = [{id:1, ...}, {id:2, ...}, {id:3, ...}];

for (let i = 0, l = items.length; i < l; ++i) {
  if (items[i].id === findThis) {
    items[i].iAmChanged = true;

Although I am a great fan of array functions, don't let them be the only tool in your toolbox. If the purpose is mutating the array, they are not the best fit.

Ignore .classpath and .project from Git

Use a .gitignore file. This allows you to ignore certain files.

Here's an example Eclipse one, which handles your classpath and project files:

Mercurial stuck "waiting for lock"

I encountered this problem on Mac OS X 10.7.5 and Mercurial 2.6.2 when trying to push. After upgrading to Mercurial 3.2.1, I got "no changes found" instead of "waiting for lock on repository". I found out that somehow the default path had gotten set to point to the same repository, so it's not too surprising that Mercurial would get confused.

How do I write to a Python subprocess' stdin?

You can provide a file-like object to the stdin argument of

The documentation for the Popen object applies here.

To capture the output, you should instead use subprocess.check_output(), which takes similar arguments. From the documentation:

>>> subprocess.check_output(
...     "ls non_existent_file; exit 0",
...     stderr=subprocess.STDOUT,
...     shell=True)
'ls: non_existent_file: No such file or directory\n'

Using external images for CSS custom cursors

I found out that you need to add the pointer eg:

    cursor: url('cursorurl.png'), pointer;

How can I put CSS and HTML code in the same file?

Two options: 1, add css inline like style="background:black" Or 2. In the head include the css as a style tag block.

Is it possible to reference one CSS rule within another?

I had this problem yesterday. @Quentin's answer is ok:

No, you cannot reference one rule-set from another.

but I made a javascript function to simulate inheritance in css (like .Net):

    var inherit_array;_x000D_
    var inherit;_x000D_
    inherit_array = [];_x000D_
    Array.from(document.styleSheets).forEach(function (styleSheet_i, index) {_x000D_
        Array.from(styleSheet_i.cssRules).forEach(function (cssRule_i, index) {_x000D_
            if ( != null) {_x000D_
                inherit ="--inherits").trim();_x000D_
            } else {_x000D_
                inherit = "";_x000D_
            if (inherit != "") {_x000D_
                inherit_array.push({ selector: cssRule_i.selectorText, inherit: inherit });_x000D_
    Array.from(document.styleSheets).forEach(function (styleSheet_i, index) {_x000D_
        Array.from(styleSheet_i.cssRules).forEach(function (cssRule_i, index) {_x000D_
            if (cssRule_i.selectorText != null) {_x000D_
                inherit_array.forEach(function (inherit_i, index) {_x000D_
                    if (cssRule_i.selectorText.split(", ").includesMember(inherit_i.inherit.split(", ")) == true) {_x000D_
                        cssRule_i.selectorText = cssRule_i.selectorText + ", " + inherit_i.selector;_x000D_

Array.prototype.includesMember = function (arr2) {_x000D_
    var arr1;_x000D_
    var includes;_x000D_
    arr1 = this;_x000D_
    includes = false;_x000D_
    arr1.forEach(function (arr1_i, index) {_x000D_
        if (arr2.includes(arr1_i) == true) {_x000D_
            includes = true;_x000D_
    return includes;_x000D_

and equivalent css:

.test {_x000D_
    background-color: yellow;_x000D_
.productBox, .imageBox {_x000D_
    --inherits: .test;_x000D_
    display: inline-block;_x000D_

and equivalent HTML :

<div class="imageBox"></div>

I tested it and worked for me, even if rules are in different css files.

Update: I found a bug in hierarchichal inheritance in this solution, and am solving the bug very soon .

Unable to Resolve Module in React Native App

I had this error and then I realized that my package.json file was mostly empty. Make sure you have all the dependencies you have first.

use yarn add DEPENDENCY_NAME to add dependencies.

Java Returning method which returns arraylist?

You need to instantiate the class it is contained within, or make the method static.

So if it is contained within class Foo:

Foo x = new Foo();
List<Integer> stuff = x.myNumbers();

or alternatively shorthand:

List<Integer> stuff = new Foo().myNumbers();

or if you make it static like so:

public static List<Integer> myNumbers()    {
    List<Integer> numbers = new ArrayList<Integer>();

you can call it like so:

List<Integer> stuff = Foo.myNumbers();

Finding the path of the program that will execute from the command line in Windows

Use the where command. The first result in the list is the one that will execute.

C:\> where notepad

According to this blog post, where.exe is included with Windows Server 2003 and later, so this should just work with Vista, Win 7, et al.

On Linux, the equivalent is the which command, e.g. which ssh.

How to use group by with union in t-sql

Identifying the column is easy:

FROM    ( SELECT    id,
          FROM      dbo.a
          SELECT    id,
          FROM      dbo.b

But it doesn't solve the main problem of this query: what's to be done with the second column values upon grouping by the first? Since (peculiarly!) you're using UNION rather than UNION ALL, you won't have entirely duplicated rows between the two subtables in the union, but you may still very well have several values of time for one value of the id, and you give no hint of what you want to do - min, max, avg, sum, or what?! The SQL engine should give an error because of that (though some such as mysql just pick a random-ish value out of the several, I believe sql-server is better than that).

So, for example, change the first line to SELECT id, MAX(time) or the like!

Detecting endianness programmatically in a C++ program

You can also do this via the preprocessor using something like boost header file which can be found boost endian

bs4.FeatureNotFound: Couldn't find a tree builder with the features you requested: lxml. Do you need to install a parser library?

Install LXML parser in python environment.

pip install lxml

Your problem will be resolve. You can also use built-in python package for the same as:

soup = BeautifulSoup(s,  "html.parser")

Note: The "HTMLParser" module has been renamed to "html.parser" in Python3

C# Double - ToString() formatting with two decimal places but no rounding

Following can be used for display only which uses the property of String ..

double value = 123.456789;
String.Format("{0:0.00}", value);

How can I easily add storage to a VirtualBox machine with XP installed?

These steps worked for me to increase the space on my windows VM:

  1. Clone the current VM and select "Full Clone" when prompted:

enter image description here

  1. Resize the VDI:

    VBoxManage modifyhd Cloned.vdi --resize 45000

  2. Run your cloned VM, go to Disk Management and extend the volume.

Angularjs $http post file and form data

I had similar problem when had to upload file and send user token info at the same time. transformRequest along with forming FormData helped:

            method: 'POST',
            url: '/upload-file',
            headers: {
                'Content-Type': 'multipart/form-data'
            data: {
                email: Utils.getUserInfo().email,
                token: Utils.getUserInfo().token,
                upload: $scope.file
            transformRequest: function (data, headersGetter) {
                var formData = new FormData();
                angular.forEach(data, function (value, key) {
                    formData.append(key, value);

                var headers = headersGetter();
                delete headers['Content-Type'];

                return formData;
        .success(function (data) {

        .error(function (data, status) {


For getting file $scope.file I used custom directive:

app.directive('file', function () {
    return {
        scope: {
            file: '='
        link: function (scope, el, attrs) {
            el.bind('change', function (event) {
                var file =[0];
                scope.file = file ? file : undefined;


<input type="file" file="file" required />

How to delete only the content of file in python

I think the easiest is to simply open the file in write mode and then close it. For example, if your file myfile.dat contains:

"This is the original content"

Then you can simply write:

f = open('myfile.dat', 'w')

This would erase all the content. Then you can write the new content to the file:

f = open('myfile.dat', 'w')
f.write('This is the new content!')

How to run python script in webpage

Well, OP didn't say server or client side, so i will just leave this here in case someone like me is looking for client side:

Skulpt is a implementation of Python to run at client side. Very interesting, no plugin required, just a simple JS.

What does -save-dev mean in npm install grunt --save-dev

To add on to Andreas' answer, you can install only the dependencies by using:

npm install --production

Retrieve column values of the selected row of a multicolumn Access listbox

For multicolumn listbox extract data from any column of selected row by


where col_num is required column ( 0 for first column)

how to concat two columns into one with the existing column name in mysql?

Instead of getting all the table columns using * in your sql statement, you use to specify the table columns you need.

You can use the SQL statement something like:


BTW, why couldn't you use FullName instead of FirstName? Like this:


Assembly Language - How to do Modulo?

If your modulus / divisor is a known constant, and you care about performance, see this and this. A multiplicative inverse is even possible for loop-invariant values that aren't known until runtime, e.g. see (But without JIT code-gen, that's less efficient than hard-coding just the steps necessary for one constant.)

Never use div for known powers of 2: it's much slower than and for remainder, or right-shift for divide. Look at C compiler output for examples of unsigned or signed division by powers of 2, e.g. on the Godbolt compiler explorer. If you know a runtime input is a power of 2, use lea eax, [esi-1] ; and eax, edi or something like that to do x & (y-1). Modulo 256 is even more efficient: movzx eax, cl has zero latency on recent Intel CPUs (mov-elimination), as long as the two registers are separate.

In the simple/general case: unknown value at runtime

The DIV instruction (and its counterpart IDIV for signed numbers) gives both the quotient and remainder. For unsigned, remainder and modulus are the same thing. For signed idiv, it gives you the remainder (not modulus) which can be negative:
e.g. -5 / 2 = -2 rem -1. x86 division semantics exactly match C99's % operator.

DIV r32 divides a 64-bit number in EDX:EAX by a 32-bit operand (in any register or memory) and stores the quotient in EAX and the remainder in EDX. It faults on overflow of the quotient.

Unsigned 32-bit example (works in any mode)

mov eax, 1234          ; dividend low half
mov edx, 0             ; dividend high half = 0.  prefer  xor edx,edx

mov ebx, 10            ; divisor can be any register or memory

div ebx       ; Divides 1234 by 10.
        ; EDX =   4 = 1234 % 10  remainder
        ; EAX = 123 = 1234 / 10  quotient

In 16-bit assembly you can do div bx to divide a 32-bit operand in DX:AX by BX. See Intel's Architectures Software Developer’s Manuals for more information.

Normally always use xor edx,edx before unsigned div to zero-extend EAX into EDX:EAX. This is how you do "normal" 32-bit / 32-bit => 32-bit division.

For signed division, use cdq before idiv to sign-extend EAX into EDX:EAX. See also Why should EDX be 0 before using the DIV instruction?. For other operand-sizes, use cbw (AL->AX), cwd (AX->DX:AX), cdq (EAX->EDX:EAX), or cqo (RAX->RDX:RAX) to set the top half to 0 or -1 according to the sign bit of the low half.

div / idiv are available in operand-sizes of 8, 16, 32, and (in 64-bit mode) 64-bit. 64-bit operand-size is much slower than 32-bit or smaller on current Intel CPUs, but AMD CPUs only care about the actual magnitude of the numbers, regardless of operand-size.

Note that 8-bit operand-size is special: the implicit inputs/outputs are in AH:AL (aka AX), not DL:AL. See 8086 assembly on DOSBox: Bug with idiv instruction? for an example.

Signed 64-bit division example (requires 64-bit mode)

   mov    rax,  0x8000000000000000   ; INT64_MIN = -9223372036854775808
   mov    ecx,  10           ; implicit zero-extension is fine for positive numbers

   cqo                       ; sign-extend into RDX, in this case = -1 = 0xFF...FF
   idiv   rcx
       ; quotient  = RAX = -922337203685477580 = 0xf333333333333334
       ; remainder = RDX = -8                  = 0xfffffffffffffff8

Limitations / common mistakes

div dword 10 is not encodeable into machine code (so your assembler will report an error about invalid operands).

Unlike with mul/imul (where you should normally use faster 2-operand imul r32, r/m32 or 3-operand imul r32, r/m32, imm8/32 instead that don't waste time writing a high-half result), there is no newer opcode for division by an immediate, or 32-bit/32-bit => 32-bit division or remainder without the high-half dividend input.

Division is so slow and (hopefully) rare that they didn't bother to add a way to let you avoid EAX and EDX, or to use an immediate directly.

div and idiv will fault if the quotient doesn't fit into one register (AL / AX / EAX / RAX, the same width as the dividend). This includes division by zero, but will also happen with a non-zero EDX and a smaller divisor. This is why C compilers just zero-extend or sign-extend instead of splitting up a 32-bit value into DX:AX.

And also why INT_MIN / -1 is C undefined behaviour: it overflows the signed quotient on 2's complement systems like x86. See Why does integer division by -1 (negative one) result in FPE? for an example of x86 vs. ARM. x86 idiv does indeed fault in this case.

The x86 exception is #DE - divide exception. On Unix/Linux systems, the kernel delivers a SIGFPE arithmetic exception signal to processes that cause a #DE exception. (On which platforms does integer divide by zero trigger a floating point exception?)

For div, using a dividend with high_half < divisor is safe. e.g. 0x11:23 / 0x12 is less than 0xff so it fits in an 8-bit quotient.

Extended-precision division of a huge number by a small number can be implemented by using the remainder from one chunk as the high-half dividend (EDX) for the next chunk. This is probably why they chose remainder=EDX quotient=EAX instead of the other way around.

Best way to implement keyboard shortcuts in a Windows Forms application?

If you have a menu then changing ShortcutKeys property of the ToolStripMenuItem should do the trick.

If not, you could create one and set its visible property to false.

Multi-dimensional arrays in Bash

I do this using associative arrays since bash 4 and setting IFS to a value that can be defined manually.

The purpose of this approach is to have arrays as values of associative array keys.

In order to set IFS back to default just unset it.

  • unset IFS

This is an example:


set -euo pipefail

# used as value in asscciative array
# associative array
declare -A wow=(
echo "default IFS"
for w in ${wow[@]}; do
  echo "  $w"

echo "IFS=:"
for w in ${wow[@]}; do
  for t in $w; do
    echo "  $t"
echo -e "\n or\n"
for w in ${!wow[@]}
  echo "  $w"
  for t in ${wow[$w]}
    echo "    $t"

unset IFS
unset w
unset t
unset wow
unset test

The output of the script below is:

default IFS



Find the nth occurrence of substring in a string

Simplest way?

text = "This is a test from a test ok" 

firstTest = text.find('test')

print text.find('test', firstTest + 1)

IF a == true OR b == true statement

check this Twig Reference.

You can do it that simple:

{% if (a or b) %}
{% endif %}

How to check cordova android version of a cordova/phonegap project?

For getting all the info about the cordova package use this command:

npm info cordova

Excel VBA For Each Worksheet Loop

Try this more succinct code:

Sub LoopOverEachColumn()
    Dim WS As Worksheet
    For Each WS In ThisWorkbook.Worksheets
        ResizeColumns WS
    Next WS
End Sub

Private Sub ResizeColumns(WS As Worksheet)
    Dim StrSize As String
    Dim ColIter As Long
    StrSize = "20.14;9.71;35.86;30.57;23.57;21.43;18.43;23.86;27.43;36.71;30.29;31.14;31;41.14;33.86"
    For ColIter = 1 To 15
        WS.Columns(ColIter).ColumnWidth = Split(StrSize, ";")(ColIter - 1)
    Next ColIter
End Sub

If you want additional columns, just change 1 to 15 to 1 to X where X is the column index of the column you want, and append the column size you want to StrSize.

For example, if you want P:P to have a width of 25, just add ;25 to StrSize and change ColIter... to ColIter = 1 to 16.

Hope this helps.

How to strip HTML tags from a string in SQL Server?

Try this. It's a modified version of the one posted by RedFilter ... this SQL removes all tags except BR, B, and P with any accompanying attributes:

 DECLARE @TempStr varchar(255)

 SET @Start = CHARINDEX('<',@HTMLText)
 SET @Length = (@End - @Start) + 1

 WHILE @Start > 0 AND @End > 0 AND @Length > 0
   IF (UPPER(SUBSTRING(@HTMLText, @Start, 3)) <> '<BR') AND (UPPER(SUBSTRING(@HTMLText, @Start, 2)) <> '<P') AND (UPPER(SUBSTRING(@HTMLText, @Start, 2)) <> '<B') AND (UPPER(SUBSTRING(@HTMLText, @Start, 3)) <> '</B')
      SET @HTMLText = STUFF(@HTMLText,@Start,@Length,'')
   SET @Start = CHARINDEX('<',@HTMLText, @End)
   SET @End = CHARINDEX('>',@HTMLText,CHARINDEX('<',@HTMLText, @Start))
   SET @Length = (@End - @Start) - 1


Failed to execute goal org.apache.maven.plugins:maven-surefire-plugin:2.12:test (default-test) on project.

I was facing the same kind of issue, your version numbers in the dependency of Selenium, TestNG, Junit should the same that you have used in your project. For example, in your project you are using the Selenium version 3.8. This version number should be mentioned in the dependency.



How to delete a stash created with git stash create?

git stash           // create stash,
git stash push -m "message" // create stash with msg,
git stash apply         // to apply stash,
git stash apply indexno // to apply  specific stash, 
git stash list          //list stash,
git stash drop indexno      //to delete stash,
git stash pop indexno,
git stash pop = stash drop + stash apply
git stash clear         //clear all your local stashed code

How to get current available GPUs in tensorflow?

There is also a method in the test util. So all that has to be done is:




Look up the Tensorflow docs for arguments.

How to linebreak an svg text within javascript?

With the tspan solution, let's say you don't know in advance where to put your line breaks: you can use this nice function, that I found here:

That automatically does line breaks for long text svg for a given width in pixel.

function wrap(text, width) {
  text.each(function() {
    var text =,
        words = text.text().split(/\s+/).reverse(),
        line = [],
        lineNumber = 0,
        lineHeight = 1.1, // ems
        y = text.attr("y"),
        dy = parseFloat(text.attr("dy")),
        tspan = text.text(null).append("tspan").attr("x", 0).attr("y", y).attr("dy", dy + "em");
    while (word = words.pop()) {
      tspan.text(line.join(" "));
      if (tspan.node().getComputedTextLength() > width) {
        tspan.text(line.join(" "));
        line = [word];
        tspan = text.append("tspan").attr("x", 0).attr("y", y).attr("dy", ++lineNumber * lineHeight + dy + "em").text(word);

Java function for arrays like PHP's join()?

Do you like my 3-lines way using only String class's methods?

static String join(String glue, String[] array) {
    String line = "";
    for (String s : array) line += s + glue;
    return (array.length == 0) ? line : line.substring(0, line.length() - glue.length());

How to convert SSH keypairs generated using PuTTYgen (Windows) into key-pairs used by ssh-agent and Keychain (Linux)

sudo apt-get install putty

This will automatically install the puttygen tool.

Now to convert the PPK file to be used with SSH command execute the following in terminal

puttygen mykey.ppk -O private-openssh -o my-openssh-key

Then, you can connect via SSH with:

ssh -v [email protected] -i my-openssh-key

How do I check CPU and Memory Usage in Java?

JMX, The MXBeans (ThreadMXBean, etc) provided will give you Memory and CPU usages.

OperatingSystemMXBean operatingSystemMXBean = (OperatingSystemMXBean) ManagementFactory.getOperatingSystemMXBean();

VIM Disable Automatic Newline At End Of File

Starting with vim v7.4 you can use

:set nofixendofline

There is some information about that change here: .

Regex that accepts only numbers (0-9) and NO characters

Your regex ^[0-9] matches anything beginning with a digit, including strings like "1A". To avoid a partial match, append a $ to the end:


This accepts any number of digits, including none. To accept one or more digits, change the * to +. To accept exactly one digit, just remove the *.

UPDATE: You mixed up the arguments to IsMatch. The pattern should be the second argument, not the first:

if (!System.Text.RegularExpressions.Regex.IsMatch(textbox.Text, "^[0-9]*$"))

CAUTION: In JavaScript, \d is equivalent to [0-9], but in .NET, \d by default matches any Unicode decimal digit, including exotic fare like ? (Myanmar 2) and ? (N'Ko 9). Unless your app is prepared to deal with these characters, stick with [0-9] (or supply the RegexOptions.ECMAScript flag).

C++ Loop through Map

As @Vlad from Moscow says, Take into account that value_type for std::map is defined the following way:

typedef pair<const Key, T> value_type

This then means that if you wish to replace the keyword auto with a more explicit type specifier, then you could this;

for ( const pair<const string, int> &p : table ) {
   std::cout << p.first << '\t' << p.second << std::endl;

Just for understanding what auto will translate to in this case.

Spring Boot value not populating

Using Environment class we can get application. Properties values


private Environment env;

and access using

String password =env.getProperty(your property key);

HTML/CSS: how to put text both right and left aligned in a paragraph

enter image description here

If the texts has different sizes and they must be underlined this is the solution:

    <td class='left'>January</td>
    <td class='right'>2014</td>


    width: 100%;
    border-bottom: 2px solid black;
    /*this is the size of the small text's baseline over part  (˜25px*3/4)*/
    line-height: 19.5px; 
table td{
    vertical-align: baseline;
    font-family: Arial;
    font-size: 40px;
    text-align: left;

    font-size: 25px;
    text-align: right;

demo here

Sorting dictionary keys in python

I like this one:

sorted(d, key=d.get)

How to install older version of node.js on Windows?

You can use Nodist for this purpose. Download it from here.


nodist                         List all installed node versions.
nodist list
nodist ls

nodist <version>               Use the specified node version globally (downloads the executable, if necessary).
nodist latest                  Use the latest available node version globally (downloads the executable, if necessary).

nodist add <version>           Download the specified node version.

More Nodist commands here

stop service in android


is wrong name for


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

Convert varchar to float IF ISNUMERIC

..extending Mikaels' answers

  • Two data types requires two columns
  • Adding e0 fixes some ISNUMERIC issues (such as + - . and empty string being accepted)

How can I debug my JavaScript code?

My first step is always to validate the HTML and to check syntax with JSLint. If you have clean markup and valid JavaScript code then it is time for Firebug or another debugger.

Styling a disabled input with css only

Let's just say you have 3 buttons:

<input type="button" disabled="disabled" value="hello world">
<input type="button" disabled value="hello world">
<input type="button" value="hello world">

To style the disabled button you can use the following css:


This will only affect the button which is disabled.

To stop the color changing when hovering you can use this too:


You can also avoid this by using a css-reset.

Get LatLng from Zip Code - Google Maps API

Here is the function I am using for my work

function getLatLngByZipcode(zipcode) 
    var geocoder = new google.maps.Geocoder();
    var address = zipcode;
    geocoder.geocode({ 'address': address }, function (results, status) {
        if (status == google.maps.GeocoderStatus.OK) {
            var latitude = results[0];
            var longitude = results[0].geometry.location.lng();
            alert("Latitude: " + latitude + "\nLongitude: " + longitude);
        } else {
            alert("Request failed.")
    return [latitude, longitude];

In angular $http service, How can I catch the "status" of error?

Since $http.get returns a 'promise' with the extra convenience methods success and error (which just wrap the result of then) you should be able to use (regardless of your Angular version):

    .then(function success(response) {
        console.log('succeeded', response); // supposed to have: data, status, headers, config, statusText
    }, function error(response) {
        console.log('failed', response); // supposed to have: data, status, headers, config, statusText

Not strictly an answer to the question, but if you're getting bitten by the "my version of Angular is different than the docs" issue you can always dump all of the arguments, even if you don't know the appropriate method signature:

  .success(function(data, foo, bar) {
    console.log(arguments); // includes data, status, etc including unlisted ones if present
  .error(function(baz, foo, bar, idontknow) {
    console.log(arguments); // includes data, status, etc including unlisted ones if present

Then, based on whatever you find, you can 'fix' the function arguments to match.

Create an array or List of all dates between two dates

I know this is an old post but try using an extension method:

    public static IEnumerable<DateTime> Range(this DateTime startDate, DateTime endDate)
        return Enumerable.Range(0, (endDate - startDate).Days + 1).Select(d => startDate.AddDays(d));

and use it like this

    var dates = new DateTime(2000, 1, 1).Range(new DateTime(2000, 1, 31));

Feel free to choose your own dates, you don't have to restrict yourself to January 2000.

Working with Enums in android

Android's preferred approach is int constants enforced with @IntDef:

public static final int GENDER_MALE = 1;
public static final int GENDER_FEMALE = 2;

public @interface Gender{}

// Example usage...
void exampleFunc(@Gender int gender) {
  switch(gender) {

     // TODO


React: how to update state.item[1] in state using setState?

Use array map with arrow function, in one line

    items:, index) =>
      index === 1 ? { ...item, name: 'newName' } : item,

Subtracting time.Duration from time in Go

There's time.ParseDuration which will happily accept negative durations, as per manual. Otherwise put, there's no need to negate a duration where you can get an exact duration in the first place.

E.g. when you need to substract an hour and a half, you can do that like so:

package main

import (

func main() {
    now := time.Now()

    fmt.Println("now:", now)

    duration, _ := time.ParseDuration("-1.5h")

    then := now.Add(duration)

    fmt.Println("then:", then)

The permissions granted to user ' are insufficient for performing this operation. (rsAccessDenied)"}

You can also make sure that the Identity in your Application Pool has the right permissions.

  1. Go to IIS Manager

  2. Click Application pools

  3. Identify the application pool of the site you are deploying reports on

  4. Check that the identity is set to some service account or user account that has admin permissions

  5. You can change the identity by stopping the pool, right clicking it, and selecting Advanced Settings...

Under Process Model is the Identity field

Why is HttpClient BaseAddress not working?

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


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

String comparison technique used by Python

This is a lexicographical ordering. It just puts things in dictionary order.

PHP - define constant inside a class

See Class Constants:

class MyClass
    const MYCONSTANT = 'constant value';

    function showConstant() {
        echo  self::MYCONSTANT. "\n";

echo MyClass::MYCONSTANT. "\n";

$classname = "MyClass";
echo $classname::MYCONSTANT. "\n"; // As of PHP 5.3.0

$class = new MyClass();

echo $class::MYCONSTANT."\n"; // As of PHP 5.3.0

In this case echoing MYCONSTANT by itself would raise a notice about an undefined constant and output the constant name converted to a string: "MYCONSTANT".

EDIT - Perhaps what you're looking for is this static properties / variables:

class MyClass
    private static $staticVariable = null;

    public static function showStaticVariable($value = null)
        if ((is_null(self::$staticVariable) === true) && (isset($value) === true))
            self::$staticVariable = $value;

        return self::$staticVariable;

MyClass::showStaticVariable(); // null
MyClass::showStaticVariable('constant value'); // "constant value"
MyClass::showStaticVariable('other constant value?'); // "constant value"
MyClass::showStaticVariable(); // "constant value"

JavaScript: changing the value of onclick with or without jQuery

Came up with a quick and dirty fix to this. Just used <select onchange='this.options[this.selectedIndex].onclick();> <option onclick='alert("hello world")' ></option> </select>

Hope this helps

jQuery - Getting the text value of a table cell in the same row as a clicked element

Nick has the right answer, but I wanted to add you could also get the cell data without needing the class name

var Something = $(this).closest('tr').find('td:eq(1)').text();

:eq(#) has a zero based index (link).

Htaccess: add/remove trailing slash from URL

This is what I've used for my latest app.

# redirect the main page to landing
##RedirectMatch 302 ^/$ /landing

# remove php ext from url
RewriteEngine on 

# File exists but has a trailing slash
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule ^/?(.*)/+$ /$1 [R=302,L,QSA]

# ok. It will still find the file but relative assets won't load
# e.g. page: /landing/  -> assets/js/main.js/main
# that's we have the rules above.
RewriteCond %{REQUEST_FILENAME} !\.php
RewriteCond %{REQUEST_FILENAME} !-d
RewriteCond %{REQUEST_FILENAME}\.php -f 
RewriteRule ^/?(.*?)/?$ $1.php

Simple file write function in C++

Switch the order of the functions or do a forward declaration of the writefiles function and it will work I think.

Get the value of checked checkbox?

Use this:


This assumes the checkboxes to check have the class "messageCheckbox", otherwise you would have to do a check if the input is the checkbox type, etc.

jQuery ID starts with

Here you go:

$('td[id^="' + value +'"]')

so if the value is for instance 'foo', then the selector will be 'td[id^="foo"]'.

Note that the quotes are mandatory: [id^="...."].


How to add click event to a iframe with JQuery

You could simulate a focus/click event by having something like the following. (adapted from $(window).blur event affecting Iframe)

$(window).blur(function () {_x000D_
  // check focus_x000D_
  if ($('iframe').is(':focus')) {_x000D_
    console.log("iframe focused");_x000D_
    $(document.activeElement).trigger("focus");// Could trigger click event instead_x000D_
  else {_x000D_
    console.log("iframe unfocused");_x000D_
  }                _x000D_
$('#iframe_id').on('focus', function(e){_x000D_
  console.log("hello im focused");_x000D_

How display only years in input Bootstrap Datepicker?

For bootstrap 3 datepicker. (Note the capital letters)

$("#datetimepicker").datetimepicker( {
  format: "YYYY",
  viewMode: "years"

SQL Server Express CREATE DATABASE permission denied in database 'master'

i have same problem, and i try this:

  1. log In As Administrator on your PC
  2. log In SQL Server Management Studio as "Windows Aunthication"
  3. Click Security > Login > choose your login where you want to create DB > right click then Properties > click server roles > then checklist 'dbcreator'.
  4. Close and log in back with your login account.

This worked for me, and hope will help you.

*sorry for my bad english

Use Excel VBA to click on a button in Internet Explorer, when the button has no "name" associated

CSS selector:

Use a CSS selector of img[src='images/toolbar/b_edit.gif']

This says select element(s) with img tag with attribute src having value of 'images/toolbar/b_edit.gif'

CSS query:

CSS query


You can apply the selector with the .querySelector method of document.


Counting the number of files in a directory using Java

Since Java 8, you can do that in three lines:

try (Stream<Path> files = Files.list(Paths.get("your/path/here"))) {
    long count = files.count();

Regarding the 5000 child nodes and inode aspects:

This method will iterate over the entries but as Varkhan suggested you probably can't do better besides playing with JNI or direct system commands calls, but even then, you can never be sure these methods don't do the same thing!

However, let's dig into this a little:

Looking at JDK8 source, Files.list exposes a stream that uses an Iterable from Files.newDirectoryStream that delegates to FileSystemProvider.newDirectoryStream.

On UNIX systems (decompiled sun.nio.fs.UnixFileSystemProvider.class), it loads an iterator: A sun.nio.fs.UnixSecureDirectoryStream is used (with file locks while iterating through the directory).

So, there is an iterator that will loop through the entries here.

Now, let's look to the counting mechanism.

The actual count is performed by the count/sum reducing API exposed by Java 8 streams. In theory, this API can perform parallel operations without much effort (with multihtreading). However the stream is created with parallelism disabled so it's a no go...

The good side of this approach is that it won't load the array in memory as the entries will be counted by an iterator as they are read by the underlying (Filesystem) API.

Finally, for the information, conceptually in a filesystem, a directory node is not required to hold the number of the files that it contains, it can just contain the list of it's child nodes (list of inodes). I'm not an expert on filesystems, but I believe that UNIX filesystems work just like that. So you can't assume there is a way to have this information directly (i.e: there can always be some list of child nodes hidden somewhere).

Removing leading and trailing spaces from a string

Boost string trim algorithm

#include <boost/algorithm/string/trim.hpp>


std::string msg = "   some text  with spaces  ";

Getting msbuild.exe without installing Visual Studio

The latest (as of Jan 2019) stand-alone MSBuild installers can be found here:

Scroll down to "Tools for Visual Studio 2019" and choose "Build Tools for Visual Studio 2019" (despite the name, it's for users who don't want the full IDE)

See this question for additional information.

How to open a txt file and read numbers in Java

public class DataStreamExample {  
     public static void main(String args[]){    
            FileWriter  fin=new FileWriter("testout.txt");    
            BufferedWriter d = new BufferedWriter(fin);
            int a[] = new int[3];
            String s="";
            for(int i=0;i<3;i++)


            FileReader in=new FileReader("testout.txt");
            BufferedReader br=new BufferedReader(in);
            String i="";
            int sum=0;
            while ((i=br.readLine())!= null)
                sum += Integer.parseInt(i);
          }catch(Exception e){System.out.println(e);}    

OUTPUT:: Success 26

Also, I used array to make it simple.... you can directly take integer input and convert it into string and send it to file. input-convert-Write-Process... its that simple.

How to create own dynamic type or dynamic object in C#?

ExpandoObject is what are you looking for.

dynamic MyDynamic = new ExpandoObject(); // note, the type MUST be dynamic to use dynamic invoking.
MyDynamic.A = "A";
MyDynamic.B = "B";
MyDynamic.C = "C";
MyDynamic.TheAnswerToLifeTheUniverseAndEverything = 42;

Maven compile with multiple src directories

Used the build-helper-maven-plugin from the post - and update src/main/generated. And mvn clean compile works on my ../common/src/main/java, or on ../common, so kept the latter. Then yes, confirming that IntelliJ IDEA (ver 10.5.2) level of the compilation failed as David Phillips mentioned. The issue was that IDEA did not add another source root to the project. Adding it manually solved the issue. It's not nice as editing anything in the project should come from maven and not from direct editing of IDEA's project options. Yet I will be able to live with it until they support build-helper-maven-plugin directly such that it will auto add the sources.

Then needed another workaround to make this work though. Since each time IDEA re-imported maven settings after a pom change me newly added source was kept on module, yet it lost it's Source Folders selections and was useless. So for IDEA - need to set these once:

  • Select - Project Settings / Maven / Importing / keep source and test folders on reimport.
  • Add - Project Structure / Project Settings / Modules / {Module} / Sources / Add Content Root.

Now keeping those folders on import is not the best practice in the world either, ..., but giving it a try.

How to get height and width of device display in angular2 using typescript?

For those who want to get height and width of device even when the display is resized (dynamically & in real-time):

  • Step 1:

In that Component do: import { HostListener } from "@angular/core";

  • Step 2:

In the component's class body write:

@HostListener('window:resize', ['$event'])
onResize(event?) {
   this.screenHeight = window.innerHeight;
   this.screenWidth = window.innerWidth;
  • Step 3:

In the component's constructor call the onResize method to initialize the variables. Also, don't forget to declare them first.

constructor() {

Complete code:

import { Component, OnInit } from "@angular/core";
import { HostListener } from "@angular/core";

  selector: "app-login",
  templateUrl: './login.component.html',
  styleUrls: ['./login.component.css']

export class FooComponent implements OnInit {
    screenHeight: number;
    screenWidth: number;

    constructor() {

    @HostListener('window:resize', ['$event'])
    getScreenSize(event?) {
          this.screenHeight = window.innerHeight;
          this.screenWidth = window.innerWidth;
          console.log(this.screenHeight, this.screenWidth);


Get data type of field in select statement in ORACLE

I usually create a view and use the DESC command:

CREATE VIEW tmp_view AS 
    , a.surname
    , b.ordernum 
FROM customer a
  JOIN orders b
    ON =

Then, the DESC command will show the type of each field.

DESC tmp_view

What is the reason for a red exclamation mark next to my project in Eclipse?

I also had this problem several times and I could 'solve' it by just deleting the messages in the "Problems"-tab and building the project again. Select the project and click on the menu bar Project -> Clean... select your project again and okay.

Initializing C# auto-properties

Update - the answer below was written before C# 6 came along. In C# 6 you can write:

public class Foo
    public string Bar { get; set; } = "bar";

You can also write read-only automatically-implemented properties, which are only writable in the constructor (but can also be given a default initial value):

public class Foo
    public string Bar { get; }

    public Foo(string bar)
        Bar = bar;

It's unfortunate that there's no way of doing this right now. You have to set the value in the constructor. (Using constructor chaining can help to avoid duplication.)

Automatically implemented properties are handy right now, but could certainly be nicer. I don't find myself wanting this sort of initialization as often as a read-only automatically implemented property which could only be set in the constructor and would be backed by a read-only field.

This hasn't happened up until and including C# 5, but is being planned for C# 6 - both in terms of allowing initialization at the point of declaration, and allowing for read-only automatically implemented properties to be initialized in a constructor body.

how to play video from url

Try Exoplayer2

It is highly customisable

    private void initializePlayer() {
         player = ExoPlayerFactory.newSimpleInstance(
             new DefaultRenderersFactory(this),
             new DefaultTrackSelector(), new DefaultLoadControl());


         player.seekTo(currentWindow, playbackPosition);

Uri uri = Uri.parse(getString(R.string.media_url_mp3));
     MediaSource mediaSource = buildMediaSource(uri);
     player.prepare(mediaSource, true, false);

private MediaSource buildMediaSource(Uri uri) {
  return new ExtractorMediaSource.Factory(
      new DefaultHttpDataSourceFactory("exoplayer-codelab")).

public void onStart() {
 if (Util.SDK_INT > 23) {

Check this url for more details

How to generate unique ID with node.js

If some one needs cryptographic-strong UUID, there is solution for that as well.

npm install generate-safe-id

Why not UUIDs?

Random UUIDs (UUIDv4) do not have enough entropy to be universally unique (ironic, eh?). Random UUIDs have only 122 bits of entropy, which suggests that a duplicate will occur after only 2^61 IDs. Additionally, some UUIDv4 implementations do not use a cryptographically strong random number generator.

This library generates 240-bit IDs using the Node.js crypto RNG, suggesting the first duplicate will occur after generating 2^120 IDs. Based on the current energy production of the human race, this threshold will be impossible to cross for the foreseeable future.

var generateSafeId = require('generate-safe-id');

var id = generateSafeId();
// id == "zVPkWyvgRW-7pSk0iRzEhdnPcnWfMRi-ZcaPxrHA"

Cloning an array in Javascript/Typescript

Cloning Arrays and Objects in javascript have a different syntax. Sooner or later everyone learns the difference the hard way and end up here.

In Typescript and ES6 you can use the spread operator for array and object:

const myClonedArray  = [...myArray];  // This is ok for [1,2,'test','bla']
                                      // But wont work for [{a:1}, {b:2}]. 
                                      // A bug will occur when you 
                                      // modify the clone and you expect the 
                                      // original not to be modified.
                                      // The solution is to do a deep copy
                                      // when you are cloning an array of objects.

To do a deep copy of an object you need an external library:

import {cloneDeep} from 'lodash';
const myClonedArray = cloneDeep(myArray);     // This works for [{a:1}, {b:2}]

The spread operator works on object as well but it will only do a shallow copy (first layer of children)

const myShallowClonedObject = {...myObject};   // Will do a shallow copy
                                               // and cause you an un expected bug.

To do a deep copy of an object you need an external library:

 import {cloneDeep} from 'lodash';
 const deeplyClonedObject = cloneDeep(myObject);   // This works for [{a:{b:2}}]

CSS transition fade on hover

This will do the trick


  transition: opacity .2s ease-out;
  -moz-transition: opacity .2s ease-out;
  -webkit-transition: opacity .2s ease-out;
  -o-transition: opacity .2s ease-out;

Injection of autowired dependencies failed; nested exception is org.springframework.beans.factory.BeanCreationException:

Add bean declaration in bean.xml file or in any other configuration file . It will resolve the error

<bean  class="com.demo.dao.RailwayDao"></bean>
<bean  class="com.demo.service.RailwayService"></bean>
<bean  class="com.demo.model.RailwayReservation"></bean>

What is

Webservices require unique namespaces so they don't confuse each others schemas and whatever with each other. A URL (domain, subdomain, subsubdomain, etc) is a clever identifier as it's "guaranteed" to be unique, and in most circumstances you've already got one.

How can I check if a string is a number?

This is my personal favorite

private static bool IsItOnlyNumbers(string searchString)
return !String.IsNullOrEmpty(searchString) && searchString.All(char.IsDigit);

How to set a default value with Html.TextBoxFor?

It turns out that if you don't specify the Model to the View method within your controller, it doesn't create a object for you with the default values.

public ViewResult Create()
  // Loads default values
  Instructor i = new Instructor();
  return View("Create", i);

public ViewResult Create()
  // Does not load default values from instructor
  return View("Create");

How to check if a value exists in an object using JavaScript

You can try this:

function checkIfExistingValue(obj, key, value) {
    return obj.hasOwnProperty(key) && obj[key] === value;
var test = [{name : "jack", sex: F}, {name: "joe", sex: M}]
console.log(test.some(function(person) { return checkIfExistingValue(person, "name", "jack"); }));

How to return temporary table from stored procedure

What version of SQL Server are you using? In SQL Server 2008 you can use Table Parameters and Table Types.

An alternative approach is to return a table variable from a user defined function but I am not a big fan of this method.

You can find an example here

Setting UILabel text to bold

Use font property of UILabel:

label.font = UIFont(name:"HelveticaNeue-Bold", size: 16.0)

or use default system font to bold text:

label.font = UIFont.boldSystemFont(ofSize: 16.0)

What ports need to be open for TortoiseSVN to authenticate (clear text) and commit?

What's the first part of your Subversion repository URL?

  • If your URL looks like: http://subversion/repos/, then you're probably going over Port 80.
  • If your URL looks like: https://subversion/repos/, then you're probably going over Port 443.
  • If your URL looks like: svn://subversion/, then you're probably going over Port 3690.
  • If your URL looks like: svn+ssh://subversion/repos/, then you're probably going over Port 22.
  • If your URL contains a port number like: http://subversion/repos:8080, then you're using that port.

I can't guarantee the first four since it's possible to reconfigure everything to use different ports, of if you go through a proxy of some sort.

If you're using a VPN, you may have to configure your VPN client to reroute these to their correct ports. A lot of places don't configure their correctly VPNs to do this type of proxying. It's either because they have some sort of anal-retentive IT person who's being overly security conscious, or because they simply don't know any better. Even worse, they'll give you a client where this stuff can't be reconfigured.

The only way around that is to log into a local machine over the VPN, and then do everything from that system.

javascript, for loop defines a dynamic variable name

You cannot create different "variable names" but you can create different object properties. There are many ways to do whatever it is you're actually trying to accomplish. In your case I would just do

for (var i = myArray.length - 1; i >= 0; i--) {    console.log(eval(myArray[i])); }; 

More generally you can create object properties dynamically, which is the type of flexibility you're thinking of.

var result = {}; for (var i = myArray.length - 1; i >= 0; i--) {     result[myArray[i]] = eval(myArray[i]);   }; 

I'm being a little handwavey since I don't actually understand language theory, but in pure Javascript (including Node) references (i.e. variable names) are happening at a higher level than at runtime. More like at the call stack; you certainly can't manufacture them in your code like you produce objects or arrays. Browsers do actually let you do this anyway though it's terrible practice, via

window['myVarName'] = 'namingCollisionsAreFun';  

(per comment)

How can I install a previous version of Python 3 in macOS using homebrew?

I tried all the answers above to install Python 3.4.4. The installation of python worked, but PIP would not be installed and nothing I could do to make it work. I was using Mac OSX Mojave, which cause some issues with zlib, openssl.

What not to do:

  • Try to avoid using Homebrew for previous version given by the formula Python or Python3.
  • Do not try to compile Python


  1. Download the macOS 64-bit installer or macOS 64-bit/32-bit installer:
  2. In previous step, it will download Python 3.6.5, if for example, you want to download Python 3.4.4, replace in the url above python-365 by python-344
  3. Download click on the file you downloaded a GUI installer will open
  4. If you downloaded python-365, after installation, to launch this version of python, you will type in your terminal python365, same thing for pip, it will be pip365

p.s: You don't have to uninstall your other version of Python on your system.


I found a much much much better solution that work on MacOSX, Windows, Linux, etc.

  1. It doesn't matter if you have already python installed or not.
  2. Download Anaconda
  3. Once installed, in terminal type: conda init
  4. In terminal,create virtual environment with any python version, for example, I picked 3.4.4: conda create -n [NameOfYour VirtualEnvironment] python=3.4.4
  5. Then, in terminal, you can check all the virtual environment you ahave created with the command: conda info --envs
  6. Then, in terminal, activate the virtual environment of your choice with: conda activate [The name of your virtual environment that was shown with the command at step 5]

Jquery .on('scroll') not firing the event while scrolling

Another option could be:

$("#ulId").scroll(function () { console.log("Event Fired"); })

Reference: Here

Unsupported method: BaseConfig.getApplicationIdSuffix()

In my case, Android Studio 3.0.1, I fixed the issue with the following two steps.

Step 1: Change Gradle plugin version in project-level build.gradle

buildscript {
    repositories {
        maven {
            url ''
            name 'Google'
    dependencies {
        classpath ''

Step 2: Change gradle version


PHP: Split a string in to an array foreach char

you can convert a string to array with str_split and use foreach

$chars = str_split($str);
foreach($chars as $char){
    // your code

How can I check if some text exist or not in the page using Selenium?

You could retrieve the body text of the whole page like this:

bodyText = self.driver.find_element_by_tag_name('body').text

then use an assert to check it like this:

self.assertTrue("the text you want to check for" in bodyText)

Of course, you can be specific and retrieve a specific DOM element's text and then check that instead of retrieving the whole page.

What's the use of "enum" in Java?

An enum type is a type whose fields consist of a fixed set of constants. Common examples include compass directions (values of NORTH, SOUTH, EAST, and WEST) and the days of the week.

public enum Day {

You should use enum types any time you need to represent a fixed set of constants. That includes natural enum types such as the planets in our solar system and data sets where you know all possible values at compile time—for example, the choices on a menu, command line flags, and so on.

Here is some code that shows you how to use the Day enum defined above:

public class EnumTest {
    Day day;

    public EnumTest(Day day) { = day;

    public void tellItLikeItIs() {
        switch (day) {
            case MONDAY:
                System.out.println("Mondays are bad.");

            case FRIDAY:
                System.out.println("Fridays are better.");

            case SATURDAY: case SUNDAY:
                System.out.println("Weekends are best.");

                System.out.println("Midweek days are so-so.");

    public static void main(String[] args) {
        EnumTest firstDay = new EnumTest(Day.MONDAY);
        EnumTest thirdDay = new EnumTest(Day.WEDNESDAY);
        EnumTest fifthDay = new EnumTest(Day.FRIDAY);
        EnumTest sixthDay = new EnumTest(Day.SATURDAY);
        EnumTest seventhDay = new EnumTest(Day.SUNDAY);

The output is:

Mondays are bad.
Midweek days are so-so.
Fridays are better.
Weekends are best.
Weekends are best.

Java programming language enum types are much more powerful than their counterparts in other languages. The enum declaration defines a class (called an enum type). The enum class body can include methods and other fields. The compiler automatically adds some special methods when it creates an enum. For example, they have a static values method that returns an array containing all of the values of the enum in the order they are declared. This method is commonly used in combination with the for-each construct to iterate over the values of an enum type. For example, this code from the Planet class example below iterates over all the planets in the solar system.

for (Planet p : Planet.values()) {
    System.out.printf("Your weight on %s is %f%n",
                      p, p.surfaceWeight(mass));

In addition to its properties and constructor, Planet has methods that allow you to retrieve the surface gravity and weight of an object on each planet. Here is a sample program that takes your weight on earth (in any unit) and calculates and prints your weight on all of the planets (in the same unit):

public enum Planet {
    MERCURY (3.303e+23, 2.4397e6),
    VENUS   (4.869e+24, 6.0518e6),
    EARTH   (5.976e+24, 6.37814e6),
    MARS    (6.421e+23, 3.3972e6),
    JUPITER (1.9e+27,   7.1492e7),
    SATURN  (5.688e+26, 6.0268e7),
    URANUS  (8.686e+25, 2.5559e7),
    NEPTUNE (1.024e+26, 2.4746e7);

    private final double mass;   // in kilograms
    private final double radius; // in meters
    Planet(double mass, double radius) {
        this.mass = mass;
        this.radius = radius;
    private double mass() { return mass; }
    private double radius() { return radius; }

    // universal gravitational constant  (m3 kg-1 s-2)
    public static final double G = 6.67300E-11;

    double surfaceGravity() {
        return G * mass / (radius * radius);
    double surfaceWeight(double otherMass) {
        return otherMass * surfaceGravity();
    public static void main(String[] args) {
        if (args.length != 1) {
            System.err.println("Usage: java Planet <earth_weight>");
        double earthWeight = Double.parseDouble(args[0]);
        double mass = earthWeight/EARTH.surfaceGravity();
        for (Planet p : Planet.values())
           System.out.printf("Your weight on %s is %f%n",
                             p, p.surfaceWeight(mass));

If you run Planet.class from the command line with an argument of 175, you get this output:

$ java Planet 175
Your weight on MERCURY is 66.107583
Your weight on VENUS is 158.374842
Your weight on EARTH is 175.000000
Your weight on MARS is 66.279007
Your weight on JUPITER is 442.847567
Your weight on SATURN is 186.552719
Your weight on URANUS is 158.397260
Your weight on NEPTUNE is 199.207413


Google Drive as FTP Server

With google-drive-ftp-adapter I have been able to access the My Drive area of Google Drive with the FileZilla FTP client. However, I have not been able to access the Shared with me area.

You can configure which Google account credentials it uses by changing the account property in the file from default to the desired Google account name. See the instructions at

Posting raw image data as multipart/form-data in curl

As of PHP 5.6 @$filePath will not work in CURLOPT_POSTFIELDS without CURLOPT_SAFE_UPLOAD being set and it is completely removed in PHP 7. You will need to use a CurlFile object, RFC here.

$fields = [
    'name' => new \CurlFile($filePath, 'image/png', 'filename.png')
curl_setopt($resource, CURLOPT_POSTFIELDS, $fields);

AngularJS ngClass conditional

Angular JS provide this functionality in ng-class Directive. In which you can put condition and also assign conditional class. You can achieve this in two different ways.

Type 1

<div ng-class="{0:'one', 1:'two',2:'three'}[status]"></div>

In this code class will be apply according to value of status value

if status value is 0 then apply class one

if status value is 1 then apply class two

if status value is 2 then apply class three

Type 2

<div ng-class="{1:'test_yes', 0:'test_no'}[status]"></div>

In which class will be apply by value of status

if status value is 1 or true then it will add class test_yes

if status value is 0 or false then it will add class test_no

How to finish current activity in Android

Just call the finish() method:


Tomcat 8 Maven Plugin for Java 8

Yes you can,

In your pom.xml, add the tomcat plugin. (You can use this for both Tomcat 7 and 8):


<!-- Tomcat plugin -->  
  <url>http:// localhost:8080/manager/text</url>  
  <server>TomcatServer</server>    *(From maven > settings.xml)*


    <role rolename="manager-gui"/>  
        <role rolename="manager-script"/>   
        <user username="admin" password="password" roles="manager-gui,manager-script" />  

settings.xml (maven > conf)


* deploy/re-deploy

mvn tomcat7:deploy OR mvn tomcat7:redeploy

Tried this on (Both Ubuntu and Windows 8/10):
* Jdk 7 & Tomcat 7
* Jdk 7 & Tomcat 8
* Jdk 8 & Tomcat 7
* Jdk 8 & Tomcat 8
* Jdk 8 & Tomcat 9

Tested on Both Jdk 7/8 & Tomcat 7/8. (Works with Tomcat 8.5 and 9)

Tomcat manager should be running or properly setup, before you can use it with maven.

Good Luck!

Duplicate ID, tag null, or parent id with another fragment for

<?xml version="1.0" encoding="utf-8"?>

  <RelativeLayout xmlns:android=""
   android:layout_height="match_parent" >

    android:layout_marginRight="15dp" >

Why don't you insert a map using the MapView object instead of MapFragment ? I am not sure if there is any limitation in MapView,though i found it helpful.

Indent List in HTML and CSS

Normally, all lists are being displayed vertically anyways. So do you want to display it horizontally?

Anyways, you asked to override the main css file and set some css locally. You cannot do it inside <ul> with style="", that it would apply on the children (<li>).

Closest thing to locally manipulating your list would be:

    li {display: inline-block;}
        <li>Black tea</li>
        <li>Green tea</li>

Creating a new column based on if-elif-else condition

For this particular relationship, you could use np.sign:

>>> df["C"] = np.sign(df.A - df.B)
>>> df
   A  B  C
a  2  2  0
b  3  1  1
c  1  3 -1

python multithreading wait till all threads finished

I just came across the same problem where I needed to wait for all the threads which were created using the for loop.I just tried out the following piece of code.It may not be the perfect solution but I thought it would be a simple solution to test:

for t in threading.enumerate():
    except RuntimeError as err:
        if 'cannot join current thread' in err:

How to import an existing X.509 certificate and private key in Java keystore to use in SSL?

If you have a PEM file (e.g. server.pem) containing:

  • the trusted certificate
  • the private key

then you can import the certificate and key into a JKS keystore like this:

1) Copy the private key from the PEM file into an ascii file (e.g. server.key)

2) Copy the cert from the PEM file into an ascii file (e.g. server.crt)

3) Export the cert and key into a PKCS12 file:

$ openssl pkcs12 -export -in server.crt -inkey server.key \
                 -out server.p12 -name [some-alias] -CAfile server.pem -caname root
  • the PEM file can be used as the argument to the -CAfile option.
  • you are prompted for an 'export' password.
  • if doing this in git bash then add winpty to the start of the command so the export password can be entered.

4) Convert the PKCS12 file to a JKS keystore:

$ keytool -importkeystore -deststorepass changeit -destkeypass changeit \
          -destkeystore keystore.jks  -srckeystore server.p12 -srcstoretype PKCS12 \
          -srcstorepass changeit
  • the srcstorepass password should match the export password from step 3)

How to show all shared libraries used by executables in Linux?

If you don't care about the path to the executable file -

ldd `which <executable>` # back quotes, not single quotes

How to call a mysql stored procedure, with arguments, from command line?

With quotes around the date:

mysql> CALL insertEvent('2012.01.01 12:12:12');

How to access site through IP address when website is on a shared host?

According with the HTTP/1.1 standard, the shared IP hosted site can be accessed by a GET request with the IP as URL and a header of the host.

Here there are two examples(wget and curl): $ wget --header '' $ curl --header ''


Apache VirtualHost 403 Forbidden

For apache Ubuntu 2.4.7 , I finally found you need to white list your virtual host in apache2.conf

# access here, or in any related virtual host.
<Directory /home/gav/public_html/>
    Options FollowSymLinks
    AllowOverride None
    Require all granted

how can I enable scrollbars on the WPF Datagrid?

Adding MaxHeight and VerticalScrollBarVisibility="Auto" on the DataGrid solved my problem.

JSON formatter in C#?

This is a variant of the accepted answer that I like to use. The commented parts result in what I consider a more readable format (you would need to comment out the adjacent code to see the difference):

public class JsonHelper
    private const int INDENT_SIZE = 4;

    public static string FormatJson(string str)
        str = (str ?? "").Replace("{}", @"\{\}").Replace("[]", @"\[\]");

        var inserts = new List<int[]>();
        bool quoted = false, escape = false;
        int depth = 0/*-1*/;

        for (int i = 0, N = str.Length; i < N; i++)
            var chr = str[i];

            if (!escape && !quoted)
                switch (chr)
                    case '{':
                    case '[':
                        inserts.Add(new[] { i, +1, 0, INDENT_SIZE * ++depth });
                        //int n = (i == 0 || "{[,".Contains(str[i - 1])) ? 0 : -1;
                        //inserts.Add(new[] { i, n, INDENT_SIZE * ++depth * -n, INDENT_SIZE - 1 });
                    case ',':
                        inserts.Add(new[] { i, +1, 0, INDENT_SIZE * depth });
                        //inserts.Add(new[] { i, -1, INDENT_SIZE * depth, INDENT_SIZE - 1 });
                    case '}':
                    case ']':
                        inserts.Add(new[] { i, -1, INDENT_SIZE * --depth, 0 });
                        //inserts.Add(new[] { i, -1, INDENT_SIZE * depth--, 0 });
                    case ':':
                        inserts.Add(new[] { i, 0, 1, 1 });

            quoted = (chr == '"') ? !quoted : quoted;
            escape = (chr == '\\') ? !escape : false;

        if (inserts.Count > 0)
            var sb = new System.Text.StringBuilder(str.Length * 2);

            int lastIndex = 0;
            foreach (var insert in inserts)
                int index = insert[0], before = insert[2], after = insert[3];
                bool nlBefore = (insert[1] == -1), nlAfter = (insert[1] == +1);

                sb.Append(str.Substring(lastIndex, index - lastIndex));

                if (nlBefore) sb.AppendLine();
                if (before > 0) sb.Append(new String(' ', before));


                if (nlAfter) sb.AppendLine();
                if (after > 0) sb.Append(new String(' ', after));

                lastIndex = index + 1;

            str = sb.ToString();

        return str.Replace(@"\{\}", "{}").Replace(@"\[\]", "[]");

MySQL pivot table query with dynamic columns

I have a slightly different way of doing this than the accepted answer. This way you can avoid using GROUP_CONCAT which has a limit of 1024 characters and will not work if you have a lot of fields.

SET @sql = '';
    @sql := CONCAT(@sql,if(@sql='','',', '),temp.output)
         'MAX(IF(pa.fieldname = ''',
          ''', pa.fieldvalue, NULL)) AS ',
        ) as output
) as temp;

                    , p.description, ', @sql, ' 
                   FROM product p
                   LEFT JOIN product_additional AS pa 
                    ON =
                   GROUP BY');

PREPARE stmt FROM @sql;

how to fix the issue "Command /bin/sh failed with exit code 1" in iphone

Cleaning the build folder (Cmd + Shift + Alt + K) worked for me