Programs & Examples On #Compare

The analysis required to assess the differences and similarities between two or more entities.

How to compare 2 files fast using .NET?

I think there are applications where "hash" is faster than comparing byte by byte. If you need to compare a file with others or have a thumbnail of a photo that can change. It depends on where and how it is using.

private bool CompareFilesByte(string file1, string file2)
    using (var fs1 = new FileStream(file1, FileMode.Open))
    using (var fs2 = new FileStream(file2, FileMode.Open))
        if (fs1.Length != fs2.Length) return false;
        int b1, b2;
            b1 = fs1.ReadByte();
            b2 = fs2.ReadByte();
            if (b1 != b2 || b1 < 0) return false;
        while (b1 >= 0);
    return true;

private string HashFile(string file)
    using (var fs = new FileStream(file, FileMode.Open))
    using (var reader = new BinaryReader(fs))
        var hash = new SHA512CryptoServiceProvider();
        return Convert.ToBase64String(hash.Hash);

private bool CompareFilesWithHash(string file1, string file2)
    var str1 = HashFile(file1);
    var str2 = HashFile(file2);
    return str1 == str2;

Here, you can get what is the fastest.

var sw = new Stopwatch();
var compare1 = CompareFilesWithHash(receiveLogPath, logPath);
Debug.WriteLine(string.Format("Compare using Hash {0}", sw.ElapsedTicks));
var compare2 = CompareFilesByte(receiveLogPath, logPath);
Debug.WriteLine(string.Format("Compare byte-byte {0}", sw.ElapsedTicks));

Optionally, we can save the hash in a database.

Hope this can help

How to compare strings

In C++ the std::string class implements the comparison operators, so you can perform the comparison using == just as you would expect:

if (string == "add") { ... }

When used properly, operator overloading is an excellent C++ feature.

How to compare two colors for similarity/difference

I expect you want to analyze a whole image at the end, don't you? So you could check for the smallest/highest difference to the identity color matrix.

Most math operations for processing graphics use matrices, because the possible algorithms using them are often faster than classical point by point distance and comparism calculations. (e.g. for operations using DirectX, OpenGL, ...)

So I think you should start here:

... and as Beska already commented above:

This may not give the best "visible" difference...

Which means also that your algorithm depends onto your definiton of "similar to" if you are processing images.

Check if enum exists in Java

One of my favorite lib: Apache Commons.

The EnumUtils can do that easily.

Following an example to validate an Enum with that library:

public enum MyEnum {
    DIV("div"), DEPT("dept"), CLASS("class");

    private final String val;

    MyEnum(String val) {
    this.val = val;

    public String getVal() {
    return val;

MyEnum strTypeEnum = null;

// test if String str is compatible with the enum 
// e.g. if you pass str = "div", it will return false. If you pass "DIV", it will return true.
if( EnumUtils.isValidEnum(MyEnum.class, str) ){
    strTypeEnum = MyEnum.valueOf(str);

How to compare arrays in C#?

Array.Equals is comparing the references, not their contents:

Currently, when you compare two arrays with the = operator, we are really using the System.Object's = operator, which only compares the instances. (i.e. this uses reference equality, so it will only be true if both arrays points to the exact same instance)


If you want to compare the contents of the arrays you need to loop though the arrays and compare the elements.

The same blog post has an example of how to do this.

Checking for duplicate strings in JavaScript array

function hasDuplicates(arr) {
    var counts = [];

    for (var i = 0; i <= arr.length; i++) {
        if (counts[arr[i]] === undefined) {
            counts[arr[i]] = 1;
        } else {
            return true;
    return false;

// [...]

var arr = [1, 1, 2, 3, 4];

if (hasDuplicates(arr)) {
  alert('Error: you have duplicates values !')

Simple Javascript (if you don't know ES6)

function hasDuplicates(arr) {
    var counts = [];

    for (var i = 0; i <= arr.length; i++) {
        if (counts[arr[i]] === undefined) {
            counts[arr[i]] = 1;
        } else {
            return true;
    return false;

// [...]

var arr = [1, 1, 2, 3, 4];

if (hasDuplicates(arr)) {
  alert('Error: you have duplicates values !')

How to parse a month name (string) to an integer for comparison in C#?

You could do something like this:

Convert.ToDate(month + " 01, 1900").Month

Mysql Compare two datetime fields

You can use the following SQL to compare both date and time -

Select * From temp where mydate > STR_TO_DATE('2009-06-29 04:00:44', '%Y-%m-%d %H:%i:%s');

Attached mysql output when I used same SQL on same kind of table and field that you mentioned in the problem-

enter image description here

It should work perfect.

Compare two dates with JavaScript

Try using this code

var f =date1.split("/");

var t =date2.split("/");

var x =parseInt(f[2]+f[1]+f[0]);

var y =parseInt(t[2]+t[1]+t[0]);

if(x > y){
    alert("date1 is after date2");

else if(x < y){
    alert("date1 is before date2");

    alert("both date are same");

Find oldest/youngest datetime object in a list

Given a list of dates dates:

Max date is max(dates)

Min date is min(dates)

How do I check for null values in JavaScript?

In JavaScript, no string is equal to null.

Maybe you expected pass == null to be true when pass is an empty string because you're aware that the loose equality operator == performs certain kinds of type coercion.

For example, this expression is true:

'' == 0

In contrast, the strict equality operator === says that this is false:

'' === 0

Given that '' and 0 are loosely equal, you might reasonably conjecture that '' and null are loosely equal. However, they are not.

This expression is false:

'' == null

The result of comparing any string to null is false. Therefore, pass == null and all your other tests are always false, and the user never gets the alert.

To fix your code, compare each value to the empty string:

pass === ''

If you're certain that pass is a string, pass == '' will also work because only an empty string is loosely equal to the empty string. On the other hand, some experts say that it's a good practice to always use strict equality in JavaScript unless you specifically want to do the type coercion that the loose equality operator performs.

If you want to know what pairs of values are loosely equal, see the table "Sameness comparisons" in the Mozilla article on this topic.

bash string compare to multiple correct values

Here's my solution

if [[ "${cms}" != +(wordpress|magento|typo3) ]]; then

Comparing the contents of two files in Sublime Text

View - Layout and View - Groups will do in latest Sublime 3


Shift+Alt+2 --> creates 2 columns

Ctrl+2 --> move selected file to column 2

This is for side by side comparison. For actual diff, there is the diff function other already mentioned. Unfortunately, I can't find a way to make columns scroll at the same time, which would be a nice feature.

How can I compare two dates in PHP?

If all your dates are posterior to the 1st of January of 1970, you could use something like:

$today = date("Y-m-d");
$expire = $row->expireDate; //from database

$today_time = strtotime($today);
$expire_time = strtotime($expire);

if ($expire_time < $today_time) { /* do Something */ }

If you are using PHP 5 >= 5.2.0, you could use the DateTime class:

$today_dt = new DateTime($today);
$expire_dt = new DateTime($expire);

if ($expire_dt < $today_dt) { /* Do something */ }

Or something along these lines.

Compare every item to every other item in ArrayList

What's the problem with using for loop inside, just like outside?

for (int j = i + 1; j < list.size(); ++j) {

In general, since Java 5, I used iterators only once or twice.

How to compare two maps by their values

The result of equals in your example is obviously false because you are comparing the map a with some values in it with an empty map b (probably a copy and paste error). I recommend to use proper variable names (so you can avoid these kinds of errors) and make use of generics, too.

    Map<String, String> first = new HashMap<String, String>();
    first.put("f"+"oo", "bar"+"bar");
    first.put("fo"+"o", "bar"+"bar");

    Map second = new HashMap();
    second.put("f"+"oo", "bar"+"bar");
    second.put("fo"+"o", "bar"+"bar");

    System.out.println("equals: " + first.equals(second));

The concatenation of your strings doesn't have any effect because it will be done at compile time.

How to compare two dates along with time in java

 // Get calendar set to the current date and time
Calendar cal = Calendar.getInstance();

// Set time of calendar to 18:00
cal.set(Calendar.HOUR_OF_DAY, 18);
cal.set(Calendar.MINUTE, 0);
cal.set(Calendar.SECOND, 0);
cal.set(Calendar.MILLISECOND, 0);

// Check if current time is after 18:00 today
boolean afterSix = Calendar.getInstance().after(cal);

if (afterSix) {
    System.out.println("Go home, it's after 6 PM!");
else {

How to compare two java objects

1) == evaluates reference equality in this case
2) im not too sure about the equals, but why not simply overriding the compare method and plant it inside MyClass?

Tool for comparing 2 binary files in Windows

I prefer to use objcopy to convert to hex, then use diff.

comparing strings in vb

If String.Compare(string1,string2,True) Then

    'perform operation


assembly to compare two numbers

As already mentioned, usually the comparison is done through subtraction.
For example, X86 Assembly/Control Flow.

At the hardware level there are special digital circuits for doing the calculations, like adders.

How to compare binary files to check if they are the same?

I ended up using hexdump to convert the binary files to there hex representation and then opened them in meld / kompare / any other diff tool. Unlike you I was after the differences in the files.

hexdump tmp/Circle_24.png > tmp/hex1.txt
hexdump /tmp/Circle_24.png > tmp/hex2.txt

meld tmp/hex1.txt tmp/hex2.txt

Compare two dates in Java


In Java 8 there is no need to use Joda-Time as it comes with a similar new API in the java.time package. Use the LocalDate class.

LocalDate date = LocalDate.of(2014, 3, 18);
LocalDate today =;

Boolean isToday = date.isEqual( today );

You can ask for the span of time between the dates with Period class.

Period difference = Period.between(date, today);

LocalDate is comparable using equals and compareTo as it holds no information about Time and Timezone.

About java.time

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

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

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

Where to obtain the java.time classes?

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

In SQL how to compare date values?

You could add the time component

WHERE mydate<='2008-11-25 23:59:59'

but that might fail on DST switchover dates if mydate is '2008-11-25 24:59:59', so it's probably safest to grab everything before the next date:

WHERE mydate < '2008-11-26 00:00:00'

MongoDb query condition on comparing 2 fields

You can use a $where. Just be aware it will be fairly slow (has to execute Javascript code on every record) so combine with indexed queries if you can.

db.T.find( { $where: function() { return this.Grade1 > this.Grade2 } } );

or more compact:

db.T.find( { $where : "this.Grade1 > this.Grade2" } );

UPD for mongodb v.3.6+

you can use $expr as described in recent answer

PHP compare two arrays and get the matched values not the difference

Simple, use array_intersect() instead:

$result = array_intersect($array1, $array2);

comparing elements of the same array in java

First things first, you need to loop to < a.length rather than a.length - 1. As this is strictly less than you need to include the upper bound.

So, to check all pairs of elements you can do:

for (int i = 0; i < a.length; i++) {
    for (int k = 0; k < a.length; k++) {
        if (a[i] != a[k]) {
            //do stuff

But this will compare, for example a[2] to a[3] and then a[3] to a[2]. Given that you are checking != this seems wasteful.

A better approach would be to compare each element i to the rest of the array:

for (int i = 0; i < a.length; i++) {
    for (int k = i + 1; k < a.length; k++) {
        if (a[i] != a[k]) {
            //do stuff

So if you have the indices [1...5] the comparison would go

  1. 1 -> 2
  2. 1 -> 3
  3. 1 -> 4
  4. 1 -> 5
  5. 2 -> 3
  6. 2 -> 4
  7. 2 -> 5
  8. 3 -> 4
  9. 3 -> 5
  10. 4 -> 5

So you see pairs aren't repeated. Think of a circle of people all needing to shake hands with each other.

How to compare type of an object in Python?

i think this should do it

if isinstance(obj, str)

Java error: Comparison method violates its general contract

You can use the following class to pinpoint transitivity bugs in your Comparators:

 * @author Gili Tzabari
public final class Comparators
     * Verify that a comparator is transitive.
     * @param <T>        the type being compared
     * @param comparator the comparator to test
     * @param elements   the elements to test against
     * @throws AssertionError if the comparator is not transitive
    public static <T> void verifyTransitivity(Comparator<T> comparator, Collection<T> elements)
        for (T first: elements)
            for (T second: elements)
                int result1 =, second);
                int result2 =, first);
                if (result1 != -result2)
                    // Uncomment the following line to step through the failed case
                    //, second);
                    throw new AssertionError("compare(" + first + ", " + second + ") == " + result1 +
                        " but swapping the parameters returns " + result2);
        for (T first: elements)
            for (T second: elements)
                int firstGreaterThanSecond =, second);
                if (firstGreaterThanSecond <= 0)
                for (T third: elements)
                    int secondGreaterThanThird =, third);
                    if (secondGreaterThanThird <= 0)
                    int firstGreaterThanThird =, third);
                    if (firstGreaterThanThird <= 0)
                        // Uncomment the following line to step through the failed case
                        //, third);
                        throw new AssertionError("compare(" + first + ", " + second + ") > 0, " +
                            "compare(" + second + ", " + third + ") > 0, but compare(" + first + ", " + third + ") == " +

     * Prevent construction.
    private Comparators()

Simply invoke Comparators.verifyTransitivity(myComparator, myCollection) in front of the code that fails.

Comparing two integer arrays in Java

For the sake of completeness, you should have a method which can check all arrays:

    public static <E> boolean compareArrays(E[] array1, E[] array2) {
      boolean b = true;
      for (int i = 0; i < array2.length; i++) {
        if (array2[i].equals(array1[i]) ) {// For String Compare
        } else {
           b = false;
      return b;

Using jQuery to compare two arrays of Javascript objects

I also found this when looking to do some array comparisons with jQuery. In my case I had strings which I knew to be arrays:

var needle = 'apple orange';
var haystack = 'kiwi orange banana apple plum';

But I cared if it was a complete match or only a partial match, so I used something like the following, based off of Sudhakar R's answer:

function compareStrings( needle, haystack ){
  var needleArr = needle.split(" "),
    haystackArr = haystack.split(" "),
    compare = $(haystackArr).not(needleArr).get().length;

  if( compare == 0 ){
    return 'all';
  } else if ( compare == haystackArr.length  ) {
    return 'none';
  } else {
    return 'partial';

IF formula to compare a date with current date and return result

You can enter the following formula in the cell where you want to see the Overdue or Not due result:

=IF(ISBLANK(O10),"",IF(O10<TODAY(),"Overdue","Not due"))

This formula first tests if the source cell is blank. If it is, then the result cell will be filled with the empty string. If the source is not blank, then the formula tests if the date in the source cell is before the current day. If it is, then the value is set to Overdue, otherwise it is set to Not due.

How to compare two files in Notepad++ v6.6.8

2018 10 25. Update.

Notepad++ 7.5.8 does not have plugin manager by default. You have to download plugins manually.

Keep in mind, if you use 64 bit version of Notepad++, you should also use 64 bit version of plugin. I had a similar issue here.

Generic deep diff between two objects

I have used this piece of code for doing the task that you describe:

function mergeRecursive(obj1, obj2) {
    for (var p in obj2) {
        try {
            if(obj2[p].constructor == Object) {
                obj1[p] = mergeRecursive(obj1[p], obj2[p]);
            // Property in destination object set; update its value.
            else if (Ext.isArray(obj2[p])) {
                // obj1[p] = [];
                if (obj2[p].length < 1) {
                    obj1[p] = obj2[p];
                else {
                    obj1[p] = mergeRecursive(obj1[p], obj2[p]);

                obj1[p] = obj2[p];
        } catch (e) {
            // Property in destination object not set; create it and set its value.
            obj1[p] = obj2[p];
    return obj1;

this will get you a new object that will merge all the changes between the old object and the new object from your form

Easiest way to compare arrays in C#

For .NET 4.0 and higher you can compare elements in array or tuples via using StructuralComparisons type:

object[] a1 = { "string", 123, true };
object[] a2 = { "string", 123, true };

Console.WriteLine (a1 == a2);        // False (because arrays is reference types)
Console.WriteLine (a1.Equals (a2));  // False (because arrays is reference types)

IStructuralEquatable se1 = a1;
//Next returns True
Console.WriteLine (se1.Equals (a2, StructuralComparisons.StructuralEqualityComparer)); 

How to compare two date values with jQuery

var startDate = $('#start_date').val().replace(/-/g,'/');
var endDate = $('#end_date').val().replace(/-/g,'/');

if(startDate > endDate){
   // do your stuff here...

Query comparing dates in SQL

please try with below query

select id,numbers_from,created_date,amount_numbers,SMS_text 
from Test_Table
convert(datetime, convert(varchar(10), created_date, 102))  <= convert(datetime,'2013-04-12')

What is best tool to compare two SQL Server databases (schema and data)?

There is one tool with source code available at

That should give flexibility as code is available.

How to compare LocalDate instances Java 8

Using equals() LocalDate does override equals:

int compareTo0(LocalDate otherDate) {
    int cmp = (year - otherDate.year);
    if (cmp == 0) {
        cmp = (month - otherDate.month);
        if (cmp == 0) {
            cmp = (day -;
    return cmp;

If you are not happy with the result of equals(), you are good using the predefined methods of LocalDate.

Notice that all of those method are using the compareTo0() method and just check the cmp value. if you are still getting weird result (which you shouldn't), please attach an example of input and output

How to know if two arrays have the same values

Why your code didn't work

JavaScript has primitive data types and non-primitive data types.

For primitive data types, == and === check whether the things on either side of the bars have the same value. That's why 1 === 1 is true.

For non-primitive data types like arrays, == and === check for reference equality. That is, they check whether arr1 and arr2 are the same object. In your example, the two arrays have the same objects in the same order, but are not equivalent.


Two arrays, arr1 and arr2, have the same members if and only if:

  • Everything in arr2 is in arr1


  • Everything in arr1 is in arr2

So this will do the trick (ES2016):

const containsAll = (arr1, arr2) => 
                arr2.every(arr2Item => arr1.includes(arr2Item))

const sameMembers = (arr1, arr2) => 
                        containsAll(arr1, arr2) && containsAll(arr2, arr1);

sameMembers(arr1, arr2); // `true`

This second solution using Underscore is closer to what you were trying to do:


_.isEqual(arr1, arr2); // `true`

It works because isEqual checks for "deep equality," meaning it looks at more than just reference equality and compares values.

A solution to your third question

You also asked how to find out which things in arr1 are not contained in arr2.

This will do it (ES2015):

const arr1 = [1, 2, 3, 4];
const arr2 = [3, 2, 1];

arr1.filter(arr1Item => !arr2.includes(arr1Item)); // `[4]`

You could also use Underscore's difference: method:

_.difference(arr1, arr2); // `[4]`


See @Redu's comment—my solution is for sameMembers, but what you may have in mind is sameMembersInOrder also-known-as deepEquals.


If you don't care about the order of the members of the arrays, ES2015+'s Set may be a better data structure than Array. See the MDN notes on how to implement isSuperset and difference using dangerous monkey-patching.

Compare 2 JSON objects

Simply parsing the JSON and comparing the two objects is not enough because it wouldn't be the exact same object references (but might be the same values).

You need to do a deep equals.

From - which seems the use jQuery.

Object.extend(Object, {
   deepEquals: function(o1, o2) {
     var k1 = Object.keys(o1).sort();
     var k2 = Object.keys(o2).sort();
     if (k1.length != k2.length) return false;
     return, function(keyPair) {
       if(typeof o1[keyPair[0]] == typeof o2[keyPair[1]] == "object"){
         return deepEquals(o1[keyPair[0]], o2[keyPair[1]])
       } else {
         return o1[keyPair[0]] == o2[keyPair[1]];


var anObj = JSON.parse(jsonString1);
var anotherObj= JSON.parse(jsonString2);

if (Object.deepEquals(anObj, anotherObj))

Comparing Class Types in Java

Check source code for equals()

public boolean equals(Object obj) {
  return this == obj;

Linq where clause compare only date value without time value

Simple workaround to this problem to compare date part only

var _My_ResetSet_Array = _DB
                    .Where(x => x.Active == true && 
                               x.DateTimeValueColumn.Year == DateTime.Now.Year
                            && x.DateTimeValueColumn.Month == DateTime.Now.Month
                            && x.DateTimeValueColumn.Day == DateTime.Now.Day);

Because 'Date' datatype is not supported by linq to entity , where as Year, Month and Day are 'int' datatypes and are supported.

Compare if BigDecimal is greater than zero

It's as simple as:

if (value.compareTo(BigDecimal.ZERO) > 0)

The documentation for compareTo actually specifies that it will return -1, 0 or 1, but the more general Comparable<T>.compareTo method only guarantees less than zero, zero, or greater than zero for the appropriate three cases - so I typically just stick to that comparison.

Compare two data.frames to find the rows in data.frame 1 that are not present in data.frame 2

Your example data does not have any duplicates, but your solution handle them automatically. This means that potentially some of the answers won't match to results of your function in case of duplicates.
Here is my solution which address duplicates the same way as yours. It also scales great!

a1 <- data.frame(a = 1:5, b=letters[1:5])
a2 <- data.frame(a = 1:3, b=letters[1:3])  <- function(a1,a2)
    a1.vec <- apply(a1, 1, paste, collapse = "")
    a2.vec <- apply(a2, 1, paste, collapse = "")
    a1.without.a2.rows <- a1[!a1.vec %in% a2.vec,]


# no duplicates - as in example code
r <- fsetdiff(a1, a2)
#[1] TRUE

# handling duplicates - make some duplicates
a1 <- rbind(a1, a1, a1)
a2 <- rbind(a2, a2, a2)
r <- fsetdiff(a1, a2, all = TRUE)
#[1] TRUE

It needs data.table 1.9.8+

Compare two files in Visual Studio

VS2019->View->Other Windows->Command Window (CTRL+ALT+A)

Tools.DiffFiles File1 File2

Case insensitive comparison of strings in shell script

One way would be to convert both strings to upper or lower:

test $(echo "string" | /bin/tr '[:upper:]' '[:lower:]') = $(echo "String" | /bin/tr '[:upper:]' '[:lower:]') && echo same || echo different

Another way would be to use grep:

echo "string" | grep -qi '^String$' && echo same || echo different

Static array vs. dynamic array in C++

Yes right the static array is created at the compile time where as the dynamic array is created on the run time. Where as the difference as far is concerned with their memory locations the static are located on the stack and the dynamic are created on the heap. Everything which gets located on heap needs the memory management until and unless garbage collector as in the case of .net framework is present otherwise there is a risk of memory leak.

Error resolving template "index", template might not exist or might not be accessible by any of the configured Template Resolvers

In the console is telling you that is a conflict with login. I think that you should declare also in the index.html thymeleaf. Something like:

    <html xmlns="" 

<meta charset="utf-8" />
<meta http-equiv="X-UA-Compatible" content="IE=edge" />

Copy from one workbook and paste into another

This should do it, let me know if you have trouble with it:

Sub foo()
Dim x As Workbook
Dim y As Workbook

'## Open both workbooks first:
Set x = Workbooks.Open(" path to copying book ")
Set y = Workbooks.Open(" path to destination book ")

'Now, copy what you want from x:
x.Sheets("name of copying sheet").Range("A1").Copy

'Now, paste to y worksheet:

'Close x:

End Sub

Alternatively, you could just:

Sub foo2()
Dim x As Workbook
Dim y As Workbook

'## Open both workbooks first:
Set x = Workbooks.Open(" path to copying book ")
Set y = Workbooks.Open(" path to destination book ")

'Now, transfer values from x to y:
y.Sheets("sheetname").Range("A1").Value = x.Sheets("name of copying sheet").Range("A1") 

'Close x:

End Sub

To extend this to the entire sheet:

With x.Sheets("name of copying sheet").UsedRange
    'Now, paste to y worksheet:
    y.Sheets("sheet name").Range("A1").Resize( _
        .Rows.Count, .Columns.Count) = .Value
End With

And yet another way, store the value as a variable and write the variable to the destination:

Sub foo3()
Dim x As Workbook
Dim y As Workbook
Dim vals as Variant

'## Open both workbooks first:
Set x = Workbooks.Open(" path to copying book ")
Set y = Workbooks.Open(" path to destination book ")

'Store the value in a variable:
vals = x.Sheets("name of sheet").Range("A1").Value

'Use the variable to assign a value to the other file/sheet:
y.Sheets("sheetname").Range("A1").Value = vals 

'Close x:

End Sub

The last method above is usually the fastest for most applications, but do note that for very large datasets (100k rows) it's observed that the Clipboard actually outperforms the array dump:

Copy/PasteSpecial vs Range.Value = Range.Value

That said, there are other considerations than just speed, and it may be the case that the performance hit on a large dataset is worth the tradeoff, to avoid interacting with the Clipboard.

How to sort the files according to the time stamp in unix?

File modification:

ls -t

Inode change:

ls -tc

File access:

ls -tu

"Newest" one at the bottom:

ls -tr

None of this is a creation time. Most Unix filesystems don't support creation timestamps.

How to draw a path on a map using kml file?

Thank Mathias Lin, tested and it works!

In addition, sample implementation of Mathias's method in activity can be as follows.

public class DirectionMapActivity extends MapActivity {

    public void onCreate(Bundle savedInstanceState) {

        MapView mapView = (MapView) findViewById(;

        // Acquire a reference to the system Location Manager
        LocationManager locationManager = (LocationManager) this.getSystemService(Context.LOCATION_SERVICE);

        String locationProvider = LocationManager.NETWORK_PROVIDER;
        Location lastKnownLocation = locationManager.getLastKnownLocation(locationProvider);

        StringBuilder urlString = new StringBuilder();
        urlString.append( Double.toString(lastKnownLocation.getLatitude() ));
        urlString.append( Double.toString(lastKnownLocation.getLongitude() ));
        urlString.append( Double.toString((double)dest[0]/1.0E6 ));
        urlString.append( Double.toString((double)dest[1]/1.0E6 ));

            // setup the url
            URL url = new URL(urlString.toString());
            // create the factory
            SAXParserFactory factory = SAXParserFactory.newInstance();
            // create a parser
            SAXParser parser = factory.newSAXParser();
            // create the reader (scanner)
            XMLReader xmlreader = parser.getXMLReader();
            // instantiate our handler
            NavigationSaxHandler navSaxHandler = new NavigationSaxHandler();
            // assign our handler
            // get our data via the url class
            InputSource is = new InputSource(url.openStream());
            // perform the synchronous parse           
            // get the results - should be a fully populated RSSFeed instance, or null on error
            NavigationDataSet ds = navSaxHandler.getParsedData();

            // draw path
            drawPath(ds, Color.parseColor("#add331"), mapView );

            // find boundary by using itemized overlay
            GeoPoint destPoint = new GeoPoint(dest[0],dest[1]);
            GeoPoint currentPoint = new GeoPoint( new Double(lastKnownLocation.getLatitude()*1E6).intValue()
                                                ,new Double(lastKnownLocation.getLongitude()*1E6).intValue() );

            Drawable dot = this.getResources().getDrawable(R.drawable.pixel);
            MapItemizedOverlay bgItemizedOverlay = new MapItemizedOverlay(dot,this);
            OverlayItem currentPixel = new OverlayItem(destPoint, null, null );
            OverlayItem destPixel = new OverlayItem(currentPoint, null, null );

            // center and zoom in the map
            MapController mc = mapView.getController();
            mc.animateTo(new GeoPoint(
                    (currentPoint.getLatitudeE6() + destPoint.getLatitudeE6()) / 2
                    , (currentPoint.getLongitudeE6() + destPoint.getLongitudeE6()) / 2));

        } catch(Exception e) {
            Log.d("DirectionMap","Exception parsing kml.");

    // and the rest of the methods in activity, e.g. drawPath() etc...

public class MapItemizedOverlay extends ItemizedOverlay{
    private ArrayList<OverlayItem> mOverlays = new ArrayList<OverlayItem>();
    private Context mContext;

    public MapItemizedOverlay(Drawable defaultMarker, Context context) {
          mContext = context;

    public void addOverlay(OverlayItem overlay) {

    protected OverlayItem createItem(int i) {
      return mOverlays.get(i);

    public int size() {
      return mOverlays.size();


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

I wrote this simple function the other day. Although for a date you don't need the larger numbers, this will cater for higher values too (1013th, 36021st etc...)

var fGetSuffix = function(nPos){

    var sSuffix = "";

    switch (nPos % 10){
        case 1:
            sSuffix = (nPos % 100 === 11) ? "th" : "st";
        case 2:
            sSuffix = (nPos % 100 === 12) ? "th" : "nd";
        case 3:
            sSuffix = (nPos % 100 === 13) ? "th" : "rd";
            sSuffix = "th";

    return sSuffix;

JavaScript Chart.js - Custom data formatting to display on tooltip

In Chart.Js 2.8.0, the configuration for custom tooltips can be found here: (Thanks to @prokaktus)

If you want to e.g. show some values with a prefix or postfix (In the example, the script adds a unit of kWh to the values in the chart), you could do this like:

options: {
  rotation: 1 * Math.PI,
  circumference: 1 * Math.PI,
  tooltips: {
    callbacks: {
      label: function(tooltipItem, data) {

        var label = data.datasets[tooltipItem.datasetIndex].data[tooltipItem.index] || '';

        if (label) {
          label += ' kWh';

        return label;

An example fiddle is here, too:

Function or sub to add new row and data to table

I needed this same solution, but if you use the native ListObject.Add() method then you avoid the risk of clashing with any data immediately below the table. The below routine checks the last row of the table, and adds the data in there if it's blank; otherwise it adds a new row to the end of the table:

Sub AddDataRow(tableName As String, values() As Variant)
    Dim sheet As Worksheet
    Dim table As ListObject
    Dim col As Integer
    Dim lastRow As Range

    Set sheet = ActiveWorkbook.Worksheets("Sheet1")
    Set table = sheet.ListObjects.Item(tableName)

    'First check if the last row is empty; if not, add a row
    If table.ListRows.Count > 0 Then
        Set lastRow = table.ListRows(table.ListRows.Count).Range
        For col = 1 To lastRow.Columns.Count
            If Trim(CStr(lastRow.Cells(1, col).Value)) <> "" Then
                Exit For
            End If
        Next col
    End If

    'Iterate through the last row and populate it with the entries from values()
    Set lastRow = table.ListRows(table.ListRows.Count).Range
    For col = 1 To lastRow.Columns.Count
        If col <= UBound(values) + 1 Then lastRow.Cells(1, col) = values(col - 1)
    Next col
End Sub

To call the function, pass the name of the table and an array of values, one value per column. You can get / set the name of the table from the Design tab of the ribbon, in Excel 2013 at least: enter image description here

Example code for a table with three columns:

Dim x(2)
x(0) = 1
x(1) = "apple"
x(2) = 2
AddDataRow "Table1", x

Sort a list of lists with a custom compare function

You need to slightly modify your compare function and use functools.cmp_to_key to pass it to sorted. Example code:

import functools

lst = [list(range(i, i+5)) for i in range(5, 1, -1)]

def fitness(item):
    return item[0]+item[1]+item[2]+item[3]+item[4]
def compare(item1, item2):
    return fitness(item1) - fitness(item2)

sorted(lst, key=functools.cmp_to_key(compare))


[[2, 3, 4, 5, 6], [3, 4, 5, 6, 7], [4, 5, 6, 7, 8], [5, 6, 7, 8, 9]]

Works :)

How to have a transparent ImageButton: Android

Try using null for the background ...


Why is it not advisable to have the database and web server on the same machine?

I can speak from first hand experience that it is often a good idea to place the web server and database on different machines. If you have an application that is resource intensive, it can easily cause the CPU cycles on the machine to peak, essentially bringing the machine to a halt. However, if your application has limited use of the database, it would probably be no big deal to have them share a server.

Multiple inheritance for an anonymous class

Anonymous classes always extend superclass or implements interfaces. for example:

button.addActionListener(new ActionListener(){ // ActionListener is an interface
    public void actionPerformed(ActionEvent e){

Moreover, although anonymous class cannot implement multiple interfaces, you can create an interface that extends other interface and let your anonymous class to implement it.

How can I parse JSON with C#?

You can use following extentions

public static class JsonExtensions
    public static T ToObject<T>(this string jsonText)
        return JsonConvert.DeserializeObject<T>(jsonText);

    public static string ToJson<T>(this T obj)
        return JsonConvert.SerializeObject(obj);

UIImageView - How to get the file name of the image assigned?

Neither UIImageView not UIImage holds on to the filename of the image loaded.

You can either

1: (as suggested by Kenny Winker above) subclass UIImageView to have a fileName property or

2: name the image files with numbers (image1.jpg, image2.jpg etc) and tag those images with the corresponding number (tag=1 for image1.jpg, tag=2 for image2.jpg etc) or

3: Have a class level variable (eg. NSString *currentFileName) which updates whenever you update the UIImageView's image

Best C# API to create PDF

My work uses Winnovative's PDF generator (We've used it mainly to convert HTML to PDF, but you can generate it other ways as well)

Print Combining Strings and Numbers

Yes there is. The preferred syntax is to favor str.format over the deprecated % operator.

print "First number is {} and second number is {}".format(first, second)

Multiple line code example in Javadoc comment

I enclose my example code with <pre class="brush: java"></pre> tags and use SyntaxHighlighter for published javadocs. It doesn't hurt IDE and makes published code examples beautiful.

Use awk to find average of a column

awk '{ sum += $2; n++ } END { if (n > 0) print sum / n; }'

Add the numbers in $2 (second column) in sum (variables are auto-initialized to zero by awk) and increment the number of rows (which could also be handled via built-in variable NR). At the end, if there was at least one value read, print the average.

awk '{ sum += $2 } END { if (NR > 0) print sum / NR }'

If you want to use the shebang notation, you could write:


{ sum += $2 }
END { if (NR > 0) print sum / NR }

You can also control the format of the average with printf() and a suitable format ("%13.6e\n", for example).

You can also generalize the code to average the Nth column (with N=2 in this sample) using:

awk -v N=2 '{ sum += $N } END { if (NR > 0) print sum / NR }'

Bloomberg BDH function with ISIN

To download ISIN code data the only place I see this is on the ISIN organizations website, try, they should have a function where you can easily download.

PHP, getting variable from another php-file

You could also use file_get_contents


 echo $data_a;

SQL Server query to find all current database names

SELECT name  
FROM sys.databases

You'll only see the databases you have permission to see.

Just what is an IntPtr exactly?

A direct interpretation

An IntPtr is an integer which is the same size as a pointer.

You can use IntPtr to store a pointer value in a non-pointer type. This feature is important in .NET since using pointers is highly error prone and therefore illegal in most contexts. By allowing the pointer value to be stored in a "safe" data type, plumbing between unsafe code segments may be implemented in safer high-level code -- or even in a .NET language that doesn't directly support pointers.

The size of IntPtr is platform-specific, but this detail rarely needs to be considered, since the system will automatically use the correct size.

The name "IntPtr" is confusing -- something like Handle might have been more appropriate. My initial guess was that "IntPtr" was a pointer to an integer. The MSDN documentation of IntPtr goes into somewhat cryptic detail without ever providing much insight about the meaning of the name.

An alternative perspective

An IntPtr is a pointer with two limitations:

  1. It cannot be directly dereferenced
  2. It doesn't know the type of the data that it points to.

In other words, an IntPtr is just like a void* -- but with the extra feature that it can (but shouldn't) be used for basic pointer arithmetic.

In order to dereference an IntPtr, you can either cast it to a true pointer (an operation which can only be performed in "unsafe" contexts) or you can pass it to a helper routine such as those provided by the InteropServices.Marshal class. Using the Marshal class gives the illusion of safety since it doesn't require you to be in an explicit "unsafe" context. However, it doesn't remove the risk of crashing which is inherent in using pointers.

Google Play app description formatting

Title, Short Description and Developer Name

  • HTML formatting is not supported in these fields, but you can include UTF-8 symbols and Emoji: ??

Full Description and What’s New:

  • For the Long Description and What’s New Section, there is a wider variety of HTML codes you can apply to format and structure your text. However, they will look slightly different in Google Play Store app and web.
  • Here is a table with codes that you can use for formatting Description and What’s New fields for your app on Google Play (originally appeared on ASO Stack blog):

enter image description here

Also you can refer this..

How to sort ArrayList<Long> in decreasing order?

By using Collections.sort() with a comparator that provides the decreasing order. See Javadoc for Collections.sort.

Convert Unix timestamp to a date string

If you find the notation awkward, maybe the -R-option does help. It outpouts the date in RFC 2822 format. So you won't need all those identifiers: date -d @1278999698 -R. Another possibility is to output the date in seconds in your locale: date -d @1278999698 +%c. Should be easy to remember. :-)

Comparing date part only without comparing time in JavaScript

If you are truly comparing date only with no time component, another solution that may feel wrong but works and avoids all Date() time and timezone headaches is to compare the ISO string date directly using string comparison:

> "2019-04-22" <= "2019-04-23"
> "2019-04-22" <= "2019-04-22"
> "2019-04-22" <= "2019-04-21"
> "2019-04-22" === "2019-04-22"

You can get the current date (UTC date, not neccesarily the user's local date) using:

> new Date().toISOString().split("T")[0]

My argument in favor of it is programmer simplicity -- you're much less likely to botch this than trying to handle datetimes and offsets correctly, probably at the cost of speed (I haven't compared performance)

How can I convert a Word document to PDF?

Check out docs-to-pdf-converter on github. Its a lightweight solution designed specifically for converting documents to pdf.


I wanted a simple program that can convert Microsoft Office documents to PDF but without dependencies like LibreOffice or expensive proprietary solutions. Seeing as how code and libraries to convert each individual format is scattered around the web, I decided to combine all those solutions into one single program. Along the way, I decided to add ODT support as well since I encountered the code too.

What is the 'instanceof' operator used for in Java?

Very simple code example:

If (object1 instanceof Class1) {
   // do something
} else if (object1 instanceof Class2) {
   // do something different

Be careful here. In the example above, if Class1 is Object, the first comparison will always be true. So, just like with exceptions, hierarchical order matters!

How do you strip a character out of a column in SQL Server?

UPDATE [TableName]
SET [ColumnName] = Replace([ColumnName], '[StringToRemove]', '[Replacement]')

In your instance it would be

UPDATE [TableName]
SET [ColumnName] = Replace([ColumnName], '[StringToRemove]', '')

Because there is no replacement (you want to get rid of it).

This will run on every row of the specified table. No need for a WHERE clause unless you want to specify only certain rows.

How to fix: /usr/lib/ version `GLIBCXX_3.4.15' not found

If someone has the same issue as I had - make sure that you don't install from the Ubuntu 14.04 repo onto a 12.04 machine - it gives this same error. Reinstalling from the proper repository fixed the issue.

Text in HTML Field to disappear when clicked?

To accomplish that, you can use the two events onfocus and onblur:

<input type="text" name="theName" value="DefaultValue"
  onblur="if(this.value==''){ this.value='DefaultValue';'#BBB';}"
  onfocus="if(this.value=='DefaultValue'){ this.value='';'#000';}"
  style="color:#BBB;" />

How to find the cumulative sum of numbers in a list?

If you're doing much numerical work with arrays like this, I'd suggest numpy, which comes with a cumulative sum function cumsum:

import numpy as np

a = [4,6,12]

#array([4, 10, 22])

Numpy is often faster than pure python for this kind of thing, see in comparison to @Ashwini's accumu:

In [136]: timeit list(accumu(range(1000)))
10000 loops, best of 3: 161 us per loop

In [137]: timeit list(accumu(xrange(1000)))
10000 loops, best of 3: 147 us per loop

In [138]: timeit np.cumsum(np.arange(1000))
100000 loops, best of 3: 10.1 us per loop

But of course if it's the only place you'll use numpy, it might not be worth having a dependence on it.

Alternative Windows shells, besides CMD.EXE?

Try Clink. It's awesome, especially if you are used to bash keybindings and features.

(As already pointed out - there is a similar question: Is there a better Windows Console Window?)

Positive Number to Negative Number in JavaScript?

In vanilla javascript

if(number > 0)_x000D_
  return -1*number;

Where number above is the positive number you intend to convert

This code will convert just positive numbers to negative numbers simple by multiplying by -1

Round up value to nearest whole number in SQL UPDATE

Combine round and ceiling to get a proper round up.

select ceiling(round(984.375000), 0)) => 984


select round(984.375000, 0) => 984.000000


select ceil (984.375000) => 985

Line break (like <br>) using only css

It works like this:

h4 {
h4:after {
    white-space: pre;


The trick comes from here: (to have more explanation)

How to use SortedMap interface in Java?

I would use TreeMap, which implements SortedMap. It is designed exactly for that.


Map<Integer, String> map = new TreeMap<Integer, String>();

// Add Items to the TreeMap
map.put(1, "One");
map.put(2, "Two");
map.put(3, "Three");

// Iterate over them
for (Map.Entry<Integer, String> entry : map.entrySet()) {
    System.out.println(entry.getKey() + " => " + entry.getValue());

See the Java tutorial page for SortedMap.
And here a list of tutorials related to TreeMap.

How can I test a change made to Jenkinsfile locally?

You can just validate your pipeline to find out syntax issues. Jenkis has nice API for Jenkisfile validation - https://jenkins_url/pipeline-model-converter/validate

Using curl and passing your .Jenkinsfile, you will get syntax check instantly

curl --user username:password -X POST -F "jenkinsfile=<jenkinsfile" https://jenkins_url/pipeline-model-converter/validate

You can add this workflow to editors:

Server.MapPath - Physical path given, virtual path expected

if you already know your folder is: E:\ftproot\sales then you do not need to use Server.MapPath, this last one is needed if you only have a relative virtual path like ~/folder/folder1 and you want to know the real path in the disk...

How do I determine the current operating system with Node.js

The variable to use would be process.platform

On Mac the variable returns darwin. On Windows, it returns win32 (even on 64 bit).

Current possible values are:

  • aix
  • darwin
  • freebsd
  • linux
  • openbsd
  • sunos
  • win32

I just set this at the top of my jakeFile:

var isWin = process.platform === "win32";

Accessing Object Memory Address

While it's true that id(object) gets the object's address in the default CPython implementation, this is generally useless... you can't do anything with the address from pure Python code.

The only time you would actually be able to use the address is from a C extension library... in which case it is trivial to get the object's address since Python objects are always passed around as C pointers.

Centering the pagination in bootstrap

You can add your custom Css:

    margin:0 auto;

Thank you

Int to byte array

Marc's answer is of course the right answer. But since he mentioned the shift operators and unsafe code as an alternative. I would like to share a less common alternative. Using a struct with Explicit layout. This is similar in principal to a C/C++ union.

Here is an example of a struct that can be used to get to the component bytes of the Int32 data type and the nice thing is that it is two way, you can manipulate the byte values and see the effect on the Int.

  using System.Runtime.InteropServices;

  struct Int32Converter
    [FieldOffset(0)] public int Value;
    [FieldOffset(0)] public byte Byte1;
    [FieldOffset(1)] public byte Byte2;
    [FieldOffset(2)] public byte Byte3;
    [FieldOffset(3)] public byte Byte4;

    public Int32Converter(int value)
      Byte1 = Byte2 = Byte3 = Byte4 = 0;
      Value = value;

    public static implicit operator Int32(Int32Converter value)
      return value.Value;

    public static implicit operator Int32Converter(int value)
      return new Int32Converter(value);

The above can now be used as follows

 Int32Converter i32 = 256;

 i32.Byte2 = 2;

Of course the immutability police may not be excited about the last possiblity :)

Convert .cer certificate to .jks

Use the following will help

keytool -import -v -trustcacerts -alias keyAlias -file server.cer -keystore cacerts.jks -keypass changeit

How to fix "'System.AggregateException' occurred in mscorlib.dll"

You could handle the exception directly so it would not crash your program (catching the AggregateException). You could also look at the Inner Exception, this will give you a more detailed explanation of what went wrong:

try {
    // your code 
} catch (AggregateException e) {


Format y axis as percent

I propose an alternative method using seaborn

Working code:

import pandas as pd
import seaborn as sns
df = pd.DataFrame(data, columns=['A', 'B'])
ax= sns.lineplot(data=df, markers= True)
ax.set(xlabel='xlabel', ylabel='ylabel', title='title')
#changing ylables ticks
y_value=['{:,.2f}'.format(x) + '%' for x in ax.get_yticks()]

enter image description here

Run Command Line & Command From VBS

The problem is on this line: "cmd.exe /C copy "S:Claims\Sound.wav" "C:\WINDOWS\Media\Sound.wav"

Your first quote next to "S:Claims" ends the string; you need to escape the quotes around your files with a second quote, like this: "cmd.exe /C copy ""S:\Claims\Sound.wav"" ""C:\WINDOWS\Media\Sound.wav"" "

You also have a typo in S:Claims\Sound.wav, should be S:\Claims\Sound.wav.

I also assume the apostrophe before Dim oShell and after Set oShell = Nothing are typos as well.

PHP date time greater than today

You are not comparing dates. You are comparing strings. In the world of string comparisons, 09/17/2015 > 01/02/2016 because 09 > 01. You need to either put your date in a comparable string format or compare DateTime objects which are comparable.

 $date_now = date("Y-m-d"); // this format is string comparable

if ($date_now > '2016-01-02') {
    echo 'greater than';
    echo 'Less than';



 $date_now = new DateTime();
 $date2    = new DateTime("01/02/2016");

if ($date_now > $date2) {
    echo 'greater than';
    echo 'Less than';


Prevent PDF file from downloading and printing

I suggest to modify pdf.js: remove the download button, convert pdf (at backend part) to some intermediate format of pdf.js and put watermark also at server side.

What is the best way to convert an array to a hash in Ruby

NOTE: For a concise and efficient solution, please see Marc-André Lafortune's answer below.

This answer was originally offered as an alternative to approaches using flatten, which were the most highly upvoted at the time of writing. I should have clarified that I didn't intend to present this example as a best practice or an efficient approach. Original answer follows.

Warning! Solutions using flatten will not preserve Array keys or values!

Building on @John Topley's popular answer, let's try:

a3 = [ ['apple', 1], ['banana', 2], [['orange','seedless'], 3] ]
h3 = Hash[*a3.flatten]

This throws an error:

ArgumentError: odd number of arguments for Hash
        from (irb):10:in `[]'
        from (irb):10

The constructor was expecting an Array of even length (e.g. ['k1','v1,'k2','v2']). What's worse is that a different Array which flattened to an even length would just silently give us a Hash with incorrect values.

If you want to use Array keys or values, you can use map:

h3 = Hash[ {|key, value| [key, value]}]
puts "h3: #{h3.inspect}"

This preserves the Array key:

h3: {["orange", "seedless"]=>3, "apple"=>1, "banana"=>2}

div inside php echo

You can also do this,

if ( ($cart->count_product) > 0) { 
  $print .= "<div class='my_class'>"
  $print .= $cart->count_product; 
  $print .= "</div>"
} else { 
   $print = ''; 
echo  $print;

How can I get the error message for the mail() function?

In my case, I couldn't get the error message in my PHP script no matter what I do (error_get_last(), or ini_set('display_errors',1);) don't show the error message

according to this post

The return value from $mail refers only to whether or not your server's mailing system accepted the message for delivery, and does not and can not in any way know whether or not you are providing valid arguments. For example, the return value would be false if sendmail failed to load (e.g. if it wasn't installed properly), but would return true if sendmail loaded properly but the recipient address doesn't exist.

I confirm this because after some failed attempts to use mail() in my PHP scripts, it turns that sendmail was not installed on my machine, however the php.ini variable sendmail_path was /usr/sbin/sendmail -t -i

1- I installed sendmail from my package manager shell> dnf install sendmail

2- I started it shell> service sendmail start

3- Now if any PHP mail() function fails I find the errors of the sendmail program logged under /var/mail/ directory. 1 file per user

For example this snippet is taken from my /var/mail/root file

The original message was received at Sun, 29 Jul 2018 22:37:51 +0200
from localhost []
   ----- The following addresses had permanent fatal errors -----
<[email protected]>
    (reason: 550 Host unknown)

My system is linux Fedora 28 with apache2.4 and PHP 7.2

npm WARN ... requires a peer of ... but none is installed. You must install peer dependencies yourself

You need to only depend on one major version of angular, so update all modules depending on angular 2.x :

  • update @angular/flex-layout to ^2.0.0-beta.9
  • update @angular/material to ^2.0.0-beta.12
  • update angularfire2 to ^4.0.0-rc.2
  • update zone.js to ^0.8.18
  • update webpack to ^3.8.1
  • add @angular/[email protected] (required for @angular/material)
  • replace angular2-google-maps by @agm/[email protected] (new name)

Convert Text to Date?

I had a very similar issue earlier. Unfortunately I looked at this thread and didn't find an answer which I was happy with. Hopefully this will help others.

Using VBA.DateSerial(year,month,day) you can overcome Excel's intrinsic bias to US date format. It also means you have full control over the data, which is something I personally prefer:

function convDate(str as string) as Date
  Dim day, month, year as integer
  year  = int(mid(str,1,4))
  month = int(mid(str,6,2))
  day   = int(mid(str,9,2))
  convDate = VBA.DateSerial(year,month,day)
end function

How to add icon inside EditText view in Android ?

You can set drawableLeft in the XML as suggested by marcos, but you might also want to set it programmatically - for example in response to an event. To do this use the method setCompoundDrawablesWithIntrincisBounds(int, int, int, int):

EditText editText = findViewById(;

// Set drawables for left, top, right, and bottom - send 0 for nothing
editTxt.setCompoundDrawablesWithIntrinsicBounds(R.drawable.myDrawable, 0, 0, 0);

What is the difference between map and flatMap and a good use case for each?

Difference in output of map and flatMap:


val a = sc.parallelize(1 to 10, 5)

a.flatMap(1 to _).collect()


 1, 1, 2, 1, 2, 3, 1, 2, 3, 4, 1, 2, 3, 4, 5, 1, 2, 3, 4, 5, 6, 1, 2, 3, 4, 5, 6, 7, 1, 2, 3, 4, 5, 6, 7, 8, 1, 2, 3, 4, 5, 6, 7, 8, 9, 1, 2, 3, 4, 5, 6, 7, 8, 9, 10

val a = sc.parallelize(List("dog", "salmon", "salmon", "rat", "elephant"), 3)

val b =


3 6 6 3 8

Set a Fixed div to 100% width of the parent container

You can use margin for .wrap container instead of padding for .wrapper:

body{ height:20000px }
#wrapper { padding: 0%; }
    float: left;
    position: relative;
    margin: 10%;
    width: 40%; 


Temporarily disable all foreign key constraints

Use the built-in sp_msforeachtable stored procedure.

To disable all constraints:


To enable all constraints:


To drop all the tables:

EXEC sp_msforeachtable "DROP TABLE ?";

Fixing slow initial load for IIS

I'd use B because that in conjunction with worker process recycling means there'd only be a delay while it's recycling. This avoids the delay normally associated with initialization in response to the first request after idle. You also get to keep the benefits of recycling.

How can I SELECT multiple columns within a CASE WHEN on SQL Server?

"Case" can return single value only, but you can use complex type:

create type foo as (a int, b text);
select (case 1 when 1 then (1,'qq')::foo else (2,'ww')::foo end).*;

Object variable or With block variable not set (Error 91)

As I wrote in my comment, the solution to your problem is to write the following:

Set hyperLinkText = hprlink.Range

Set is needed because TextRange is a class, so hyperLinkText is an object; as such, if you want to assign it, you need to make it point to the actual object that you need.

Java method to swap primitives

AFAIS, no one mentions of atomic reference.


public void swap(AtomicInteger a, AtomicInteger b){


public void swap(AtomicReference<String> a, AtomicReference<String> b){

Init function in javascript and how it works

That pattern will create a new execution context (EC) in which any local variable objects (VO's) will live, and will likewise die when the EC exits. The only exception to this lifetime is for VO's which become part of a closure.

Please note that JavaScript has no magic "init" function. You might associate this pattern with such since most any self-respecting JS library (jQuery, YUI, etc.) will do this so that they don't pollute the global NS more than they need to.

A demonstration:

var x = 1; // global VO
    var x = 2; // local VO
x == 1; // global VO, unchanged by the local VO

The 2nd set of "brackets" (those are actually called parens, or a set of parentheses), are simply to invoke the function expression directly preceding it (as defined by the prior set of parenthesis).

How to initialize a private static const map in C++?

You could try this:


class MyClass {
    static const std::map<key, value> m_myMap; 
    static const std::map<key, value> createMyStaticConstantMap();
    static std::map<key, value> getMyConstantStaticMap( return m_myMap );
}; //MyClass


#include "MyClass.h"

const std::map<key, value> MyClass::m_myMap = MyClass::createMyStaticConstantMap();

const std::map<key, value> MyClass::createMyStaticConstantMap() {
    std::map<key, value> mMap;
    mMap.insert( std::make_pair( key1, value1 ) );
    mMap.insert( std::make_pair( key2, value2 ) );
    // ....
    mMap.insert( std::make_pair( lastKey, lastValue ) ); 
    return mMap;
} // createMyStaticConstantMap

With this implementation your classes constant static map is a private member and can be accessible to other classes using a public get method. Otherwise since it is constant and can not change, you can remove the public get method and move the map variable into the classes public section. I would however leave the createMap method private or protected if inheritance and or polymorphism is required. Here are some samples of use.

 std::map<key,value> m1 = MyClass::getMyMap();
 // then do work on m1 or
 unsigned index = some predetermined value
 MyClass::getMyMap().at( index ); // As long as index is valid this will 
 // retun map.second or map->second value so if in this case key is an
 // unsigned and value is a std::string then you could do
 std::cout << std::string( MyClass::getMyMap().at( some index that exists in map ) ); 
// and it will print out to the console the string locted in the map at this index. 
//You can do this before any class object is instantiated or declared. 

 //If you are using a pointer to your class such as:
 std::shared_ptr<MyClass> || std::unique_ptr<MyClass>
 // Then it would look like this:
 pMyClass->getMyMap().at( index ); // And Will do the same as above
 // Even if you have not yet called the std pointer's reset method on
 // this class object. 

 // This will only work on static methods only, and all data in static methods must be available first.

I had edited my original post, there was nothing wrong with the original code in which I posted for it compiled, built and ran correctly, it was just that my first version I presented as an answer the map was declared as public and the map was const but wasn't static.

Common elements comparison between 2 lists

You can also use sets and get the commonalities in one line: subtract the set containing the differences from one of the sets.

A = [1,2,3,4]
B = [2,4,7,8]
commonalities = set(A) - (set(A) - set(B))

How do I clear all options in a dropdown box?

This is a short way:

document.getElementById('mySelect').innerText = null;

One line, no for, no JQuery, simple.

When & why to use delegates?

I agree with everything that is said already, just trying to put some other words on it.

A delegate can be seen as a placeholder for a/some method(s).

By defining a delegate, you are saying to the user of your class, "Please feel free to assign, any method that matches this signature, to the delegate and it will be called each time my delegate is called".

Typical use is of course events. All the OnEventX delegate to the methods the user defines.

Delegates are useful to offer to the user of your objects some ability to customize their behavior. Most of the time, you can use other ways to achieve the same purpose and I do not believe you can ever be forced to create delegates. It is just the easiest way in some situations to get the thing done.

Read input stream twice

You can wrap input stream with PushbackInputStream. PushbackInputStream allows to unread ("write back") bytes which were already read, so you can do like this:

public class StreamTest {
  public static void main(String[] args) throws IOException {
    byte[] bytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

    InputStream originalStream = new ByteArrayInputStream(bytes);

    byte[] readBytes = getBytes(originalStream, 3);
    printBytes(readBytes); // prints: 1 2 3

    readBytes = getBytes(originalStream, 3);
    printBytes(readBytes); // prints: 4 5 6

    // now let's wrap it with PushBackInputStream

    originalStream = new ByteArrayInputStream(bytes);

    InputStream wrappedStream = new PushbackInputStream(originalStream, 10); // 10 means that maximnum 10 characters can be "written back" to the stream

    readBytes = getBytes(wrappedStream, 3);
    printBytes(readBytes); // prints 1 2 3

    ((PushbackInputStream) wrappedStream).unread(readBytes, 0, readBytes.length);

    readBytes = getBytes(wrappedStream, 3);
    printBytes(readBytes); // prints 1 2 3


  private static byte[] getBytes(InputStream is, int howManyBytes) throws IOException {
    System.out.print("Reading stream: ");

    byte[] buf = new byte[howManyBytes];

    int next = 0;
    for (int i = 0; i < howManyBytes; i++) {
      next =;
      if (next > 0) {
        buf[i] = (byte) next;
    return buf;

  private static void printBytes(byte[] buffer) throws IOException {
    System.out.print("Reading stream: ");

    for (int i = 0; i < buffer.length; i++) {
      System.out.print(buffer[i] + " ");


Please note that PushbackInputStream stores internal buffer of bytes so it really creates a buffer in memory which holds bytes "written back".

Knowing this approach we can go further and combine it with FilterInputStream. FilterInputStream stores original input stream as a delegate. This allows to create new class definition which allows to "unread" original data automatically. The definition of this class is following:

public class TryReadInputStream extends FilterInputStream {
  private final int maxPushbackBufferSize;

  * Creates a <code>FilterInputStream</code>
  * by assigning the  argument <code>in</code>
  * to the field <code></code> so as
  * to remember it for later use.
  * @param in the underlying input stream, or <code>null</code> if
  *           this instance is to be created without an underlying stream.
  public TryReadInputStream(InputStream in, int maxPushbackBufferSize) {
    super(new PushbackInputStream(in, maxPushbackBufferSize));
    this.maxPushbackBufferSize = maxPushbackBufferSize;

   * Reads from input stream the <code>length</code> of bytes to given buffer. The read bytes are still avilable
   * in the stream
   * @param buffer the destination buffer to which read the data
   * @param offset  the start offset in the destination <code>buffer</code>
   * @aram length how many bytes to read from the stream to buff. Length needs to be less than
   *        <code>maxPushbackBufferSize</code> or IOException will be thrown
   * @return number of bytes read
   * @throws in case length is
  public int tryRead(byte[] buffer, int offset, int length) throws IOException {

    // NOTE: below reading byte by byte instead of "int bytesRead =, 0, maxBytesOfResponseToLog);"
    // because read() guarantees to read a byte

    int bytesRead = 0;

    int nextByte = 0;

    for (int i = 0; (i < length) && (nextByte >= 0); i++) {
      nextByte = read();
      if (nextByte >= 0) {
        buffer[offset + bytesRead++] = (byte) nextByte;

    if (bytesRead > 0) {
      ((PushbackInputStream) in).unread(buffer, offset, bytesRead);

    return bytesRead;


  public byte[] tryRead(int maxBytesToRead) throws IOException {

    ByteArrayOutputStream baos = new ByteArrayOutputStream(); // as ByteArrayOutputStream to dynamically allocate internal bytes array instead of allocating possibly large buffer (if maxBytesToRead is large)

    // NOTE: below reading byte by byte instead of "int bytesRead =, 0, maxBytesOfResponseToLog);"
    // because read() guarantees to read a byte

    int nextByte = 0;

    for (int i = 0; (i < maxBytesToRead) && (nextByte >= 0); i++) {
      nextByte = read();
      if (nextByte >= 0) {
        baos.write((byte) nextByte);

    byte[] buffer = baos.toByteArray();

    if (buffer.length > 0) {
      ((PushbackInputStream) in).unread(buffer, 0, buffer.length);

    return buffer;


  private void validateMaxLength(int length) throws IOException {
    if (length > maxPushbackBufferSize) {
      throw new IOException(
        "Trying to read more bytes than maxBytesToRead. Max bytes: " + maxPushbackBufferSize + ". Trying to read: " +


This class has two methods. One for reading into existing buffer (defintion is analogous to calling public int read(byte b[], int off, int len) of InputStream class). Second which returns new buffer (this may be more effective if the size of buffer to read is unknown).

Now let's see our class in action:

public class StreamTest2 {
  public static void main(String[] args) throws IOException {
    byte[] bytes = new byte[] { 1, 2, 3, 4, 5, 6, 7, 8, 9 };

    InputStream originalStream = new ByteArrayInputStream(bytes);

    byte[] readBytes = getBytes(originalStream, 3);
    printBytes(readBytes); // prints: 1 2 3

    readBytes = getBytes(originalStream, 3);
    printBytes(readBytes); // prints: 4 5 6

    // now let's use our TryReadInputStream

    originalStream = new ByteArrayInputStream(bytes);

    InputStream wrappedStream = new TryReadInputStream(originalStream, 10);

    readBytes = ((TryReadInputStream) wrappedStream).tryRead(3); // NOTE: no manual call to "unread"(!) because TryReadInputStream handles this internally
    printBytes(readBytes); // prints 1 2 3

    readBytes = ((TryReadInputStream) wrappedStream).tryRead(3); 
    printBytes(readBytes); // prints 1 2 3

    readBytes = ((TryReadInputStream) wrappedStream).tryRead(3);
    printBytes(readBytes); // prints 1 2 3

    // we can also call normal read which will actually read the bytes without "writing them back"
    readBytes = getBytes(wrappedStream, 3);
    printBytes(readBytes); // prints 1 2 3

    readBytes = getBytes(wrappedStream, 3);
    printBytes(readBytes); // prints 4 5 6

    readBytes = ((TryReadInputStream) wrappedStream).tryRead(3); // now we can try read next bytes
    printBytes(readBytes); // prints 7 8 9

    readBytes = ((TryReadInputStream) wrappedStream).tryRead(3); 
    printBytes(readBytes); // prints 7 8 9



preg_match(); - Unknown modifier '+'

This happened to me because I put a variable in the regex and sometimes its string value included a slash. Solution: preg_quote.

Are there any standard exit status codes in Linux?

When Linux returns 0, it means success. Anything else means failure, each program has its own exit codes, so it would been quite long to list them all... !

About the 11 error code, it's indeed the segmentation fault number, mostly meaning that the program accessed a memory location that was not assigned.

Connect different Windows User in SQL Server Management Studio (2005 or later)

None of these answers did what I needed: Login to a remote server using a different domain account than I was logged into on my local machine, and it's a client's domain across a vpn. I don't want to be on their domain!

Instead, on the connect to server dialog, select "Windows Authentication", click the Options button, and then on the Additional Connection Parameters tab, enter

user id=domain\user;password=password

SSMS won't remember, but it will connect with that account.

MySQL 'Order By' - sorting alphanumeric correctly

I hate this, but this will work

order by lpad(name, 10, 0)  <-- assuming maximum string length is 10
                            <-- you can adjust to a bigger length if you want to

Failure during conversion to COFF: file invalid or corrupt

I had this issue and I solved it with this thread

disable incremental linking, by going to

    Project Properties 
       -> Configuration Properties 
           -> Linker (General) 
              -> Enable Incremental Linking -> "No (/INCREMENTAL:NO)"

Vertical align text in block element

DO NOT USE THE 4th solution from top if you are using ag-grid. It will fix the issue for aligning the element in middle but it might break the thing in ag-grid (for me i was not able to select checkbox after some row). Problem is not with the solution or ag-grid but somehow the combination is not good.


li a {
    width: 300px;
    height: 100px;
    margin: auto 0;
    display: inline-block;
    vertical-align: middle;
    background: red;  

li a:after {
    display: inline-block;
    width: 1px solid transparent;
    height: 100%;
    vertical-align: middle;

How to make full screen background in a web page

Use the following code in your CSS

html { _x000D_
  background: url(images/bg.jpg) no-repeat center center fixed; _x000D_
  -webkit-background-size: cover;_x000D_
  -moz-background-size: cover;_x000D_
  -o-background-size: cover;_x000D_
  background-size: cover;_x000D_
_x000D_ here's the link where i found it:

What's the difference between subprocess Popen and call (how can I use them)?

The other answer is very complete, but here is a rule of thumb:

  • call is blocking:

    print('hello')  # only executed when notepad is closed
  • Popen is non-blocking:

    print('hello')  # immediately executed

CSV with comma or semicolon?

Initially it was to be a comma, however as the comma is often used as a decimal point it wouldnt be such good separator, hence others like the semicolon, mostly country dependant

Vuejs: v-model array in multiple input

You're thinking too DOM, it's a hard as hell habit to break. Vue recommends you approach it data first.

It's kind of hard to tell in your exact situation but I'd probably use a v-for and make an array of finds to push to as I need more.

Here's how I'd set up my instance:

new Vue({
  el: '#app',
  data: {
    finds: []
  methods: {
    addFind: function () {
      this.finds.push({ value: '' });

And here's how I'd set up my template:

<div id="app">
  <div v-for="(find, index) in finds">
    <input v-model="find.value" :key="index">
  <button @click="addFind">
    New Find

Although, I'd try to use something besides an index for the key.

Here's a demo of the above:

Docker - Container is not running

This happens with images for which the script does not launch a service awaiting requests, therefore the container exits at the end of the script.

This is typically the case with most base OS images (centos, debian, etc.), or also with the node images.

Your best bet is to run the image in interactive mode. Example below with the node image:

docker run -it node /bin/bash

Output is

root@cacc7897a20c:/# echo $SHELL

How get sound input from microphone in python, and process it on the fly?

I know it's an old question, but if someone is looking here again... see .

It has a nice example "Input to Ouput Pass-Through" here .

... and a lot of other examples as well ...

Java ArrayList - Check if list is empty

Alternatively, you may also want to check by the .size() method. The list that isn't empty will have a size more than zero

if (numbers.size()>0){
//execute your code

Display rows with one or more NaN values in pandas dataframe

Suppose gamma1 and gamma2 are two such columns for which df.isnull().any() gives True value , the following code can be used to print the rows.

bool1 = pd.isnull(df['gamma1'])
bool2 = pd.isnull(df['gamma2'])

Is It Possible to NSLog C Structs (Like CGRect or CGPoint)?

Since Stack Overflow’s broken RSS just resurrected this question for me, here’s my almost-general solution: JAValueToString

This lets you write JA_DUMP(cgPoint) and get cgPoint = {0, 0} logged.

Python Math - TypeError: 'NoneType' object is not subscriptable

lista = list.sort(lista)

This should be


The .sort() method is in-place, and returns None. If you want something not in-place, which returns a value, you could use

sorted_list = sorted(lista)

Aside #1: please don't call your lists list. That clobbers the builtin list type.

Aside #2: I'm not sure what this line is meant to do:

print str("value 1a")+str(" + ")+str("value 2")+str(" = ")+str("value 3a ")+str("value 4")+str("\n")

is it simply

print "value 1a + value 2 = value 3a value 4"

? In other words, I don't know why you're calling str on things which are already str.

Aside #3: sometimes you use print("something") (Python 3 syntax) and sometimes you use print "something" (Python 2). The latter would give you a SyntaxError in py3, so you must be running 2.*, in which case you probably don't want to get in the habit or you'll wind up printing tuples, with extra parentheses. I admit that it'll work well enough here, because if there's only one element in the parentheses it's not interpreted as a tuple, but it looks strange to the pythonic eye..

The exception TypeError: 'NoneType' object is not subscriptable happens because the value of lista is actually None. You can reproduce TypeError that you get in your code if you try this at the Python command line:


The reason that lista gets set to None is because the return value of list.sort() is None... it does not return a sorted copy of the original list. Instead, as the documentation points out, the list gets sorted in-place instead of a copy being made (this is for efficiency reasons).

If you do not want to alter the original version you can use

other_list = sorted(lista)

Using NSPredicate to filter an NSArray based on NSDictionary keys

NSPredicate is only available in iPhone 3.0.

You won't notice that until try to run on device.

Can I loop through a table variable in T-SQL?

Here's another answer, similar to Justin's, but doesn't need an identity or aggregate, just a primary (unique) key.

declare @table1 table(dataKey int, dataCol1 varchar(20), dataCol2 datetime)
declare @dataKey int
while exists select 'x' from @table1
    select top 1 @dataKey = dataKey 
    from @table1 
    order by /*whatever you want:*/ dataCol2 desc

    -- do processing

    delete from @table1 where dataKey = @dataKey

How do I set the request timeout for one controller action in an mvc application

You can set this programmatically in the controller:-

HttpContext.Current.Server.ScriptTimeout = 300;

Sets the timeout to 5 minutes instead of the default 110 seconds (what an odd default?)

Python xticks in subplots

See the (quite) recent answer on the matplotlib repository, in which the following solution is suggested:

  • If you want to set the xticklabels:

    ax.set_xticklabels([1,4,5], fontsize=12)
  • If you want to only increase the fontsize of the xticklabels, using the default values and locations (which is something I personally often need and find very handy):

    ax.tick_params(axis="x", labelsize=12) 
  • To do it all at once:

    plt.setp(ax.get_xticklabels(), fontsize=12, fontweight="bold", 

docker container ssl certificates

As was suggested in a comment above, if the certificate store on the host is compatible with the guest, you can just mount it directly.

On a Debian host (and container), I've successfully done:

docker run -v /etc/ssl/certs:/etc/ssl/certs:ro ...

Print an integer in binary format in Java

Binary representation of given int x with left padded zeros:

org.apache.commons.lang3.StringUtils.leftPad(Integer.toBinaryString(x), 32, '0')

Getting Database connection in pure JPA setup

Here is a code snippet that works with Hibernate 4 based on Dominik's answer

Connection getConnection() {
    Session session = entityManager.unwrap(Session.class);
    MyWork myWork = new MyWork();
    return myWork.getConnection();

private static class MyWork implements Work {

    Connection conn;

    public void execute(Connection arg0) throws SQLException {
        this.conn = arg0;

    Connection getConnection() {
        return conn;


How to get host name with port from a http or https request

You can use HttpServletRequest.getRequestURL and HttpServletRequest.getRequestURI.

StringBuffer url = request.getRequestURL();
String uri = request.getRequestURI();
int idx = (((uri != null) && (uri.length() > 0)) ? url.indexOf(uri) : url.length());
String host = url.substring(0, idx); //base url
idx = host.indexOf("://");
if(idx > 0) {
  host = host.substring(idx); //remove scheme if present

Selecting default item from Combobox C#

Remember that collections in C# are zero-based (in other words, the first item in a collection is at position zero). If you have two items in your list, and you want to select the last item, use SelectedIndex = 1.

Required attribute on multiple checkboxes with the same name?

Here is improvement for icova's answer. It also groups inputs by name.

  var allRequiredCheckboxes = $(':checkbox[required]');
  var checkboxNames = [];

  for (var i = 0; i < allRequiredCheckboxes.length; ++i){
    var name = allRequiredCheckboxes[i].name;

  checkboxNames = checkboxNames.reduce(function(p, c) {
    if (p.indexOf(c) < 0) p.push(c);
    return p;
  }, []);

  for (var i in checkboxNames){
      var name = checkboxNames[i];
      var checkboxes = $('input[name="' + name + '"]');
        if(':checked')) {
        } else {
          checkboxes.attr('required', 'required');


Creating new table with SELECT INTO in SQL

The syntax for creating a new table is

CREATE TABLE new_table
  FROM old_table

This will create a new table named new_table with whatever columns are in old_table and copy the data over. It will not replicate the constraints on the table, it won't replicate the storage attributes, and it won't replicate any triggers defined on the table.

SELECT INTO is used in PL/SQL when you want to fetch data from a table into a local variable in your PL/SQL block.

Java web start - Unable to load resource

I'm not sure exactly what the problem is, but I have looked at one of my jnlp files and I have put in the full path to each of my jar files. (I have a velocity template that generates the app.jnlp file which places it in all the correct places when my maven build runs)

One thing I have seen happen is that the jnlp file is re-downloaded by the by the webstart runtime, and it uses the href attribute (which is left blank in your jnlp file) to re-download the file. I would start there, and try adding the full path into the jnlp files too...I've found webstart to be a fickle mistress!

What is the iBeacon Bluetooth Profile

Just to reconcile the difference between sandeepmistry's answer and davidgyoung's answer:

02 01 1a 1a ff 4C 00

Is part of the advertising data format specification [1]

  02 # length of following AD structure
  01 # <<Flags>> AD Structure [2]
  1a # read as b00011010. 
     # In this case, LE General Discoverable,
     # and simultaneous BR/EDR but this may vary by device!

  1a # length of following AD structure
  FF # Manufacturer specific data [3]
4C00 # Apple Inc [4]
0215 # ?? some 2-byte header

Missing from the AD is a Service [5] definition. I think the iBeacon protocol itself has no relationship to the GATT and standard service discovery. If you download RedBearLab's iBeacon program, you'll see that they happen to use the GATT for configuring the advertisement parameters, but this seems to be specific to their implementation, and not part of the spec. The AirLocate program doesn't seem to use the GATT for configuration, for instance, according to LightBlue and or other similar programs I tried.


  1. Core Bluetooth Spec v4, Vol 3, Part C, 11
  2. Vol 3, Part C, 18.1
  3. Vol 3, Part C, 18.11
  5. Vol 3, Part C, 18.2

.NET / C# - Convert char[] to string

One other way:

char[] chars = {'a', ' ', 's', 't', 'r', 'i', 'n', 'g'};
string s = string.Join("", chars);
//we get "a string"
// or for fun:
string s = string.Join("_", chars);
//we get "a_ _s_t_r_i_n_g"

1067 error on attempt to start MySQL

In my case, I have unzipped XAMPP ina a second disk on my installation, "F". When I tried to start as a service, the return was "1067". The solution was to edit my.ini, inserting the "f:" drive in the files lines. It solved the problem.

Class JavaLaunchHelper is implemented in both ... libinstrument.dylib. One of the two will be used. Which one is undefined

As other answers detail, this is a bug in the JDK (up to u45) which will be fixed in JDK7u60 - while this is not out yet, you may download the b01 from:

It's beta, but fixed that issue for me.

How can I get the current page name in WordPress?

Show the title before the loop starts:

$page_title = $wp_query->post->post_title;

How do I store data in local storage using Angularjs?

There is one more alternative module which has more activity than ngStorage


reducing number of plot ticks

If somebody still gets this page in search results:

fig, ax = plt.subplots()


every_nth = 4
for n, label in enumerate(ax.xaxis.get_ticklabels()):
    if n % every_nth != 0:

How to style HTML5 range input to have different color before and after slider?

A small update to this one:

if you use the following it will update on the fly rather than on mouse release.

"change mousemove", function"

$('input[type="range"]').on("change mousemove", function () {
    var val = ($(this).val() - $(this).attr('min')) / ($(this).attr('max') - $(this).attr('min'));

                '-webkit-gradient(linear, left top, right top, '
                + 'color-stop(' + val + ', #2f466b), '
                + 'color-stop(' + val + ', #d3d3db)'
                + ')'

setting y-axis limit in matplotlib

This worked at least in matplotlib version 2.2.2:

plt.axis([None, None, 0, 100])

Probably this is a nice way to set up for example xmin and ymax only, etc.

How can I pass arguments to anonymous functions in JavaScript?

<input type="button" value="Click me" id="myButton" />

<script type="text/javascript">
    var myButton = document.getElementById("myButton");

    myButton.myMessage = "it's working";

    myButton.onclick = function() { alert(this.myMessage); };


This works in my test suite which includes everything from IE6+. The anonymous function is aware of the object which it belongs to therefore you can pass data with the object that's calling it ( in this case myButton ).

VBA - Select columns using numbers?

you can use range with cells to get the effect you want (but it would be better not to use select if you don't have to)

For n = 1 to 5
do sth
next n

Pass parameter from a batch file to a PowerShell script

Add the parameter declaration at the top of ps1 file


  # Our preferred encoding
  [string]$Encoding = "UTF8"

write ("Encoding : {0}" -f $Encoding)


C:\temp> .\test.ps1 -Encoding ASCII
Encoding : ASCII

CMake output/build directory

You should not rely on a hard coded build dir name in your script, so the line with ../Compile must be changed.

It's because it should be up to user where to compile.

Instead of that use one of predefined variables: (look for CMAKE_BINARY_DIR and CMAKE_CURRENT_BINARY_DIR)

HTML Input Type Date, Open Calendar by default

This is not possible with native HTML input elements. You can use webshim polyfill, which gives you this option by using this markup.

<input type="date" data-date-inline-picker="true" />

Here is a small demo

Make a nav bar stick

To make header sticky, first you have to give position: fixed; for header in css. Then you can adjust width and height etc. I would highly recommand to follow this article. How to create a sticky website header

Here is code as well to work around on header to make it sticky.

header { 
   position: fixed; 
   right: 0; 
   left: 0; 
   z-index: 999;

This code above will go inside your styles.css file.

could not access the package manager. is the system running while installing android application

You need to wait for the emulator to full start - takes a few minutes. Once it is fully started (UI on the emulator will change), it should work.

You will need to restart the app after the emulator is running and choose the running emulator when prompted.

Converting a vector<int> to string

template<typename T>
string str(T begin, T end)
    stringstream ss;
    bool first = true;
    for (; begin != end; begin++)
        if (!first)
            ss << ", ";
        ss << *begin;
        first = false;
    return ss.str();

This is the str function that can make integers turn into a string and not into a char for what the integer represents. Also works for doubles.

Get value of a string after last slash in JavaScript


var afterDot = value.substr(value.lastIndexOf('_') + 1);


var myString = 'asd/f/df/xc/asd/test.jpg'
var parts    = myString.split('/');
var answer   = parts[parts.length - 1];

Replace '_' || '/' to your own need

Finding multiple occurrences of a string within a string in Python

Maybe not so Pythonic, but somewhat more self-explanatory. It returns the position of the word looked in the original string.

def retrieve_occurences(sequence, word, result, base_counter):
     indx = sequence.find(word)
     if indx == -1:
         return result
     result.append(indx + base_counter)
     base_counter += indx + len(word)
     return retrieve_occurences(sequence[indx + len(word):], word, result, base_counter)

how to detect search engine bots with php?

Here's a Search Engine Directory of Spider names

Then you use $_SERVER['HTTP_USER_AGENT']; to check if the agent is said spider.

if(strstr(strtolower($_SERVER['HTTP_USER_AGENT']), "googlebot"))
    // what to do

Inserting HTML elements with JavaScript

Have a look at insertAdjacentHTML

var element = document.getElementById("one");
var newElement = '<div id="two">two</div>'
element.insertAdjacentHTML( 'afterend', newElement )
// new DOM structure: <div id="one">one</div><div id="two">two</div>

position is the position relative to the element you are inserting adjacent to:

'beforebegin' Before the element itself

'afterbegin' Just inside the element, before its first child

'beforeend' Just inside the element, after its last child

'afterend' After the element itself

Get class list for element with jQuery

I had a similar issue, for an element of type image. I needed to check whether the element was of a certain class. First I tried with:


but I got a nice "this function is not available for this element".

Then I inspected my element on the DOM explorer and I saw a very nice attribute that I could use: className. It contained the names of all the classes of my element separated by blank spaces.

$('img').className // it contains "class1 class2 class3"

Once you get this, just split the string as usual.

In my case this worked:

var listOfClassesOfMyElement= $('img').className.split(" ");

I am assuming this would work with other kinds of elements (besides img).

Hope it helps.

Notice: Undefined variable: _SESSION in "" on line 9

First, you'll need to add session_start() at the top of any page that you wish to use SESSION variables on.

Also, you should check to make sure the variable is set first before using it:

    echo $_SESSION['SESS_fname'];

Or, simply:

echo (isset($_SESSION['SESS_fname']) ? $_SESSION['SESS_fname'] : "Visitor");

How to get single value from this multi-dimensional PHP array

Use array_shift function

$myarray = array_shift($myarray);

This will move array elements one level up and you can access any array element without using [0] key

echo $myarray['email'];  

will show [email protected]

HTML button to NOT submit form

I think this is the most annoying little peculiarity of HTML... That button needs to be of type "button" in order to not submit.

<button type="button">My Button</button>

Update 5-Feb-2019: As per the HTML Living Standard (and also HTML 5 specification):

The missing value default and invalid value default are the Submit Button state.

Android REST client, Sample?

Disclaimer: I am involved in the rest2mobile open source project

Another alternative as a REST client is to use rest2mobile.

The approach is slightly different as it uses concrete rest examples to generate the client code for the REST service. The code replaces the REST URL and JSON payloads with native java methods and POJOs. It also automatically handles server connections, asynchronous invocations and POJO to/from JSON conversions.

Note that this tool comes in different flavors (cli, plugins, android/ios/js support) and you can use the android studio plugin to generate the API directly into your app.

All the code can be found on github here.

pythonw.exe or python.exe?

See here:

pythonw.exe "This suppresses the terminal window on startup."

Change auto increment starting number?

just export the table with data .. then copy its sql like

  `emp_badgenumber` int(20) NOT NULL AUTO_INCREMENT,
  `emp_fullname` varchar(100) NOT NULL,
  `emp_father_name` varchar(30) NOT NULL,
  `emp_mobile` varchar(20) DEFAULT NULL,
  `emp_cnic` varchar(20) DEFAULT NULL,
  `emp_gender` varchar(10) NOT NULL,
  `emp_is_deleted` tinyint(4) DEFAULT '0',
  `emp_registration_date` timestamp NOT NULL DEFAULT CURRENT_TIMESTAMP,
  `emp_overtime_allowed` tinyint(4) DEFAULT '1',
  PRIMARY KEY (`emp_badgenumber`),
  UNIQUE KEY `bagdenumber` (`emp_badgenumber`),
  KEY `emp_badgenumber` (`emp_badgenumber`),
  KEY `emp_badgenumber_2` (`emp_badgenumber`)

now change auto increment value and execute sql.

Python Anaconda - How to Safely Uninstall

In my case Anaconda3 was not installed in home directory. Instead, it was installed in root. Therefore, I had to do the following to get it uninstalled:

sudo rm -rf /anaconda3/bin/python

SQLite Reset Primary Key Field

As an alternate option, if you have the Sqlite Database Browser and are more inclined to a GUI solution, you can edit the sqlite_sequence table where field name is the name of your table. Double click the cell for the field seq and change the value to 0 in the dialogue box that pops up.

Can you detect "dragging" in jQuery?

jQuery plugin based on Simen Echholt's answer. I called it single click.

 * jQuery plugin: Configure mouse click that is triggered only when no mouse move was detected in the action.
 * @param callback
jQuery.fn.singleclick = function(callback) {
    return $(this).each(function() {
        var singleClickIsDragging = false;
        var element = $(this);

        // Configure mouse down listener.
        element.mousedown(function() {
            $(window).mousemove(function() {
                singleClickIsDragging = true;

        // Configure mouse up listener.
        element.mouseup(function(event) {
            var wasDragging = singleClickIsDragging;
            singleClickIsDragging = false;
            if(wasDragging) {

            // Since no mouse move was detected then call callback function.
  , event);

In use:

element.singleclick(function(event) {
    alert('Single/simple click!');


How to split elements of a list?

Something like:

>>> l = ['element1\t0238.94', 'element2\t2.3904', 'element3\t0139847']
>>> [i.split('\t', 1)[0] for i in l]
['element1', 'element2', 'element3']

Permission denied on accessing host directory in Docker

See this Project Atomic blog post about Volumes and SELinux for the full story.


This got easier recently since Docker finally merged a patch which will be showing up in docker-1.7 (We have been carrying the patch in docker-1.6 on RHEL, CentOS, and Fedora).

This patch adds support for "z" and "Z" as options on the volume mounts (-v).

For example:

docker run -v /var/db:/var/db:z rhel7 /bin/sh

Will automatically do the chcon -Rt svirt_sandbox_file_t /var/db described in the man page.

Even better, you can use Z.

docker run -v /var/db:/var/db:Z rhel7 /bin/sh

This will label the content inside the container with the exact MCS label that the container will run with, basically it runs chcon -Rt svirt_sandbox_file_t -l s0:c1,c2 /var/db where s0:c1,c2 differs for each container.

Git Pull While Ignoring Local Changes?

Look at git stash to put all of your local changes into a "stash file" and revert to the last commit. At that point, you can apply your stashed changes, or discard them.

How do I activate a Spring Boot profile when running from IntelliJ?

For Spring Boot 2.1.0 and later you can use

mvn spring-boot:run,bar

How to set an environment variable only for the duration of the script?

Just put

export HOME=/blah/whatever

at the point in the script where you want the change to happen. Since each process has its own set of environment variables, this definition will automatically cease to have any significance when the script terminates (and with it the instance of bash that has a changed environment).

How to run a cron job inside a docker container?

When you deploy your container on another host, just note that it won't start any processes automatically. You need to make sure that 'cron' service is running inside your container. In our case, I am using Supervisord with other services to start cron service.

command=/etc/init.d/cron restart

Font scaling based on width of container

Pure-CSS solution with calc(), CSS units and math

This is precisely not what OP asks, but may make someone's day. This answer is not spoon-feedingly easy and needs some researching on the developer end.

I came finally to get a pure-CSS solution for this using calc() with different units. You will need some basic mathematical understanding of formulas to work out your expression for calc().

When I worked this out, I had to get a full-page-width responsive header with some padding few parents up in DOM. I'll use my values here, replace them with your own.

To mathematics

You will need:

  • Nicely adjusted ratio in some viewport. I used 320 pixels, thus I got 24 pixels high and 224 pixels wide, so the ratio is 9.333... or 28 / 3
  • The container width, I had padding: 3em and full width so this got to 100wv - 2 * 3em

X is the width of container, so replace it with your own expression or adjust the value to get full-page text. R is the ratio you will have. You can get it by adjusting the values in some viewport, inspecting element width and height and replacing them with your own values. Also, it is width / heigth ;)

x = 100vw - 2 * 3em = 100vw - 6em
r = 224px/24px = 9.333... = 28 / 3

y = x / r
  = (100vw - 6em) / (28 / 3)
  = (100vw - 6em) * 3 / 28
  = (300vw - 18em) / 28
  = (75vw - 4.5rem) / 7

And bang! It worked! I wrote

font-size: calc((75vw - 4.5rem) / 7)

to my header and it adjusted nicely in every viewport.

But how does it work?

We need some constants up here. 100vw means the full width of viewport, and my goal was to establish full-width header with some padding.

The ratio. Getting a width and height in one viewport got me a ratio to play with, and with ratio I know what the height should be in other viewport width. Calculating them with hand would take plenty of time and at least take lots of bandwidth, so it's not a good answer.


I wonder why no-one has figured this out and some people are even telling that this would be impossible to tinker with CSS. I don't like to use JavaScript in adjusting elements, so I don't accept JavaScript (and forget about jQuery) answers without digging more. All in all, it's good that this got figured out and this is one step to pure-CSS implementations in website design.

I apologize of any unusual convention in my text, I'm not native speaker in English and am also quite new to writing Stack Overflow answers.

It should also be noted that we have evil scrollbars in some browsers. For example, when using Firefox I noticed that 100vw means the full width of viewport, extending under scrollbar (where content cannot expand!), so the fullwidth text has to be margined carefully and preferably get tested with many browsers and devices.

Format date and time in a Windows batch script

There is another easy way of doing it:

set HH=%time:~0,2%
if %HH% LEQ 9 (
set HH=%time:~1,1%

Selecting the first "n" items with jQuery

You probably want to read up on slice. Your code will look something like this:


Subset of rows containing NA (missing) values in a chosen column of a data frame

Never use =='NA' to test for missing values. Use instead. This should do it:

new_DF <- DF[rowSums( > 0,]

or in case you want to check a particular column, you can also use

new_DF <- DF[$Var),]

In case you have NA character values, first run

Df[Df=='NA'] <- NA

to replace them with missing values.

No signing certificate "iOS Distribution" found

I got the "No signing certificate" error when running Xcode 11.3 on macOS 10.14.x Mojave. (but after Xcode 12 was released.)

I was also using Fastlane. My fix was to set generate_apple_certs to false when running Match. This seemed to generate signing certificates that were backwards-compatible with Xcode 11.3

Match documentation -

This is the relevant section of my Fastfile:

platform :ios do
  lane :certs do
    force = false
    match(type: "development", generate_apple_certs: false, force: force, app_identifier: "")
    match(type: "adhoc",       generate_apple_certs: false, force: force, app_identifier: "")
    match(type: "appstore",    generate_apple_certs: false, force: force, app_identifier: "")


Reading a simple text file

Having a file in your assets folder requires you to use this piece of code in order to get files from the assets folder:


In this example, getAssets() returns an AssetManager instance and then you're free to use whatever method you want from the AssetManager API.

How to get row number from selected rows in Oracle

The below query helps to get the row number in oracle,


Is embedding background image data into CSS as Base64 good or bad practice?

I disagree with the recommendation to create separate CSS files for non-editorial images.

Assuming the images are for UI purposes, it's presentation layer styling, and as mentioned above, if you're doing mobile UI's its definitely a good idea to keep all styling in a single file so it can be cached once.

How can I get the name of an object in Python?

Here is my answer, I am also using globals().items()

    def get_name_of_obj(obj, except_word = ""):

        for name, item in globals().items():
            if item == obj and name != except_word:
                return name

I added except_word because I want to filter off some word used in for loop. If you didn't add it, the keyword in for loop may confuse this function, sometimes the keyword like "each_item" in the following case may show in the function's result, depends on what you have done to your loop.


    for each_item in [objA, objB, objC]:
        get_name_of_obj(obj, "each_item")


    >>> objA = [1, 2, 3]
    >>> objB = ('a', {'b':'thi is B'}, 'c')
    >>> for each_item in [objA, objB]:
    ...     get_name_of_obj(each_item)
    >>> for each_item in [objA, objB]:
    ...     get_name_of_obj(each_item)
    >>> objC = [{'a1':'a2'}]
    >>> for item in [objA, objB, objC]:
    ...     get_name_of_obj(item)
    'item'  <<<<<<<<<< --------- this is no good
    >>> for item in [objA, objB]:
    ...     get_name_of_obj(item)
    'item'     <<<<<<<<--------this is no good
    >>> for item in [objA, objB, objC]:
    ...     get_name_of_obj(item, "item")
    'objB'  <<<<<<<<<<--------- now it's ok

Hope this can help.

Adding Buttons To Google Sheets and Set value to Cells on clicking

It is possible to insert an image in a Google Spreadsheet using Google Apps Script. However, the image should have been hosted publicly over internet. At present, it is not possible to insert private images from Google Drive.

You can use following code to insert an image through script.

  function insertImageOnSpreadsheet() {
  // Name of the specific sheet in the spreadsheet.

  var ss = SpreadsheetApp.openByUrl(SPREADSHEET_URL);
  var sheet = ss.getSheetByName(SHEET_NAME);

  var response = UrlFetchApp.fetch(
  var binaryData = response.getContent();

  // Insert the image in cell A1.
  var blob = Utilities.newBlob(binaryData, 'image/png', 'MyImageName');
  sheet.insertImage(blob, 1, 1);

Above example has been copied from this link. Check noogui's reply for details.

In case you need to insert image from Google Drive, please check this link for current updates.

Why does range(start, end) not include end?

Because it's more common to call range(0, 10) which returns [0,1,2,3,4,5,6,7,8,9] which contains 10 elements which equals len(range(0, 10)). Remember that programmers prefer 0-based indexing.

Also, consider the following common code snippet:

for i in range(len(li)):

Could you see that if range() went up to exactly len(li) that this would be problematic? The programmer would need to explicitly subtract 1. This also follows the common trend of programmers preferring for(int i = 0; i < 10; i++) over for(int i = 0; i <= 9; i++).

If you are calling range with a start of 1 frequently, you might want to define your own function:

>>> def range1(start, end):
...     return range(start, end+1)
>>> range1(1, 10)
[1, 2, 3, 4, 5, 6, 7, 8, 9, 10]

PHP error: "The zip extension and unzip command are both missing, skipping."

For Debian Jessie (which is the current default for the PHP image on Docker Hub):

apt-get install --yes zip unzip php-pclzip

You can omit the --yes, but it's useful when you're RUN-ing it in a Dockerfile.

How to link to a <div> on another page?

Create an anchor:

<a name="anchor" id="anchor"></a> 

then link to it:

<a href="http://server/page.html#anchor">Link text</a>

How can I use an array of function pointers?

Can use it in the way like this:

//! Define:
#define F_NUM 3
int (*pFunctions[F_NUM])(void * arg);

//! Initialise:
int someFunction(void * arg) {
    int a= *((int*)arg);
    return a*a;

pFunctions[0]= someFunction;

//! Use:
int someMethod(int idx, void * arg, int * result) {
    int done= 0;
    if (idx < F_NUM && pFunctions[idx] != NULL) {
        *result= pFunctions[idx](arg);
        done= 1;
    return done;

int x= 2;
int z= 0;
someMethod(0, (void*)&x, &z);
assert(z == 4);

How to check if input file is empty in jQuery

Just check the length of files property, which is a FileList object contained on the input element

if( document.getElementById("videoUploadFile").files.length == 0 ){
    console.log("no files selected");

Android Studio with Google Play Services

Most of these answers only address compile-time dependencies, but you'll find a host of NoClassDef exceptions at runtime. That's because you need more than the google-play-services.jar. It references resources that are part of the library project, and those are not included correctly if you only have the jar.

What worked best for me was to first get the project setup correctly in eclipse. Have your project structured so that it includes both your app and the library, as described here:

Then export your app project from eclipse, and import into Android Studio as described here: Make sure to export both your app project and the google play services library project. When importing it will detect the library project and import it as a module. I just accepted all defaults during the project import process.

How to check if $? is not equal to zero in unix shell scripting?

<run your last command on this line>
if [ ${a} -ne 0 ]; then echo "do something"; fi

use whatever command you want to use instead of the echo "do something" command

Correctly Parsing JSON in Swift 3

Swift has a powerful type inference. Lets get rid of "if let" or "guard let" boilerplate and force unwraps using functional approach:

  1. Here is our JSON. We can use optional JSON or usual. I'm using optional in our example:
let json: Dictionary<String, Any>? = ["current": ["temperature": 10]]
  1. Helper functions. We need to write them only once and then reuse with any dictionary:
/// Curry
public func curry<A, B, C>(_ f: @escaping (A, B) -> C) -> (A) -> (B) -> C {
    return { a in
        { f(a, $0) }

/// Function that takes key and optional dictionary and returns optional value
public func extract<Key, Value>(_ key: Key, _ json: Dictionary<Key, Any>?) -> Value? {
    return json.flatMap {

/// Function that takes key and return function that takes optional dictionary and returns optional value
public func extract<Key, Value>(_ key: Key) -> (Dictionary<Key, Any>?) -> Value? {
    return curry(extract)(key)

/// Precedence group for our operator
precedencegroup RightApplyPrecedence {
    associativity: right
    higherThan: AssignmentPrecedence
    lowerThan: TernaryPrecedence

/// Apply. g § f § a === g(f(a))
infix operator § : RightApplyPrecedence
public func §<A, B>(_ f: (A) -> B, _ a: A) -> B {
    return f(a)

/// Wrapper around operator "as".
public func cast<A, B>(_ a: A) -> B? {
    return a as? B
  1. And here is our magic - extract the value:
let temperature = (extract("temperature") § extract("current") § json) ?? NSNotFound

Just one line of code and no force unwraps or manual type casting. This code works in playground, so you can copy and check it. Here is an implementation on GitHub.

Can I use if (pointer) instead of if (pointer != NULL)?

I think as a rule of thumb, if your if-expression can be re-written as

const bool local_predicate = *if-expression*;
if (local_predicate) ...

such that it causes NO WARNINGS, then THAT should be the preferred style for the if-expression. (I know I get warnings when I assign an old C BOOL (#define BOOL int) to a C++ bool, let alone pointers.)

Prevent cell numbers from incrementing in a formula in Excel

In Excel 2013 and resent versions, you can use F2 and F4 to speed things up when you want to toggle the lock.

About the keys:

  • F2 - With a cell selected, it places the cell in formula edit mode.
  • F4 - Toggles the cell reference lock (the $ signs).

  • Example scenario with 'A4'.

    • Pressing F4 will convert 'A4' into '$A$4'
    • Pressing F4 again converts '$A$4' into 'A$4'
    • Pressing F4 again converts 'A$4' into '$A4'
    • Pressing F4 again converts '$A4' back to the original 'A4'

How To:

  • In Excel, select a cell with a formula and hit F2 to enter formula edit mode. You can also perform these next steps directly in the Formula bar. (Issue with F2 ? Double check that 'F Lock' is on)

    • If the formula has one cell reference;
      • Hit F4 as needed and the single cell reference will toggle.
    • If the forumla has more than one cell reference, hitting F4 (without highlighting anything) will toggle the last cell reference in the formula.
    • If the formula has more than one cell reference and you want to change them all;
      • You can use your mouse to highlight the entire formula or you can use the following keyboard shortcuts;
      • Hit End key (If needed. Cursor is at end by default)
      • Hit Ctrl + Shift + Home keys to highlight the entire formula
      • Hit F4 as needed
    • If the formula has more than one cell reference and you only want to edit specific ones;
      • Highlight the specific values with your mouse or keyboard ( Shift and arrow keys) and then hit F4 as needed.


  • These notes are based on my observations while I was looking into this for one of my own projects.
  • It only works on one cell formula at a time.
  • Hitting F4 without selecting anything will update the locking on the last cell reference in the formula.
  • Hitting F4 when you have mixed locking in the formula will convert everything to the same thing. Example two different cell references like '$A4' and 'A$4' will both become 'A4'. This is nice because it can prevent a lot of second guessing and cleanup.
  • Ctrl+A does not work in the formula editor but you can hit the End key and then Ctrl + Shift + Home to highlight the entire formula. Hitting Home and then Ctrl + Shift + End.
  • OS and Hardware manufactures have many different keyboard bindings for the Function (F Lock) keys so F2 and F4 may do different things. As an example, some users may have to hold down you 'F Lock' key on some laptops.
  • 'DrStrangepork' commented about F4 actually closes Excel which can be true but it depends on what you last selected. Excel changes the behavior of F4 depending on the current state of Excel. If you have the cell selected and are in formula edit mode (F2), F4 will toggle cell reference locking as Alexandre had originally suggested. While playing with this, I've had F4 do at least 5 different things. I view F4 in Excel as an all purpose function key that behaves something like this; "As an Excel user, given my last action, automate or repeat logical next step for me".

How to stop process from .BAT file?

taskkill /F /IM notepad.exe this is the best way to kill the task from task manager.

How to export library to Jar in Android Studio?

Include the following into build.gradle:

android.libraryVariants.all { variant ->
    task("generate${}Javadoc", type: Javadoc) {
        description "Generates Javadoc for $"
        source = variant.javaCompile.source
        ext.androidJar = "${android.plugin.sdkDirectory}/platforms/${android.compileSdkVersion}/android.jar"
        classpath = files(variant.javaCompile.classpath.files) + files(ext.androidJar)

    task("javadoc${}", type: Jar) {
        classifier = "javadoc"
        description "Bundles Javadoc into a JAR file for $"
        from tasks["generate${}Javadoc"]


    task("jar${}", type: Jar) {
        description "Bundles compiled .class files into a JAR file for $"
        dependsOn variant.javaCompile
        from variant.javaCompile.destinationDir
        exclude '**/R.class', '**/R$*.class', '**/R.html', '**/R.*.html'

You can then execute gradle with: ./gradlew clean javadocRelease jarRelease which will build you your Jar and also a javadoc jar into the build/libs/ folder.

EDIT: With android gradle tools 1.10.+ getting the android SDK dir is different than before. You have to change the following (thanks Vishal!):


instead of


How do I change the default port (9000) that Play uses when I execute the "run" command?

Play 2.0-RC4

It is important to include quotes around the play command you want to run. In my case without the quotes play would still run on port 9000.

play "run 8080"

Alternatively you could run the following from the play console (type 'play' to get to the console)

run 8080

Reload content in modal (twitter bootstrap)

You can force Modal to refresh the popup by adding this line at the end of the hide method of the Modal plugin (If you are using bootstrap-transition.js v2.1.1, it should be at line 836)


Or with an event listener

$('#modal').on('hidden', function() {

Expected corresponding JSX closing tag for input Reactjs

All tags must have enclosing tags. In my case, the hr and input elements weren't closed properly.

Parent Error was: JSX element 'div' has no corresponding closing tag, due to code below:

<hr class="my-4">


<hr class="my-4"/>

The parent elements will show errors due to child element errors. Therefore, start investigating from most inner elements up to the parent ones.

Basic example of using .ajax() with JSONP?

<!DOCTYPE html>
<style>img{ height: 100px; float: left; }</style>
<script src=""></script>
<title>An JSONP example </title>
<div id="images">
  format: "json"
function(data) {
  $.each(data.items, function(i,item){


The above code helps in getting images from the Flicker API. This uses the GET method for getting images using JSONP. It can be found in detail in here

The breakpoint will not currently be hit. No symbols have been loaded for this document in a Silverlight application

Goto Project Properties -> Build -> Advanced...

In the "Output" section select "full" in Debug Info dropdown

What is ".NET Core"?

.NET Core is an open source and cross platform version of .NET. Microsoft products, besides the great abilities that they have, were always expensive for usual users, especially end users of products that has been made by .NET technologies.

Most of the low-level customers prefer to use Linux as their OS and before .NET Core they would not like to use Microsoft technologies, despite the great abilities of them. But after .NET Core production, this problem is solved completely and we can satisfy our customers without considering their OS, etc.

c++ compile error: ISO C++ forbids comparison between pointer and integer

You must remember to use single quotes for char constants. So use

if (answer == 'y') return true;

Rather than

if (answer == "y") return true;

I tested this and it works

SMTP server response: 530 5.7.0 Must issue a STARTTLS command first

I know that PHPMailer library can handle that kind of SMTP transactions.

Also, a fake sendmail with sendmail-SSL library should do the job.

Show git diff on file in staging area

In order to see the changes that have been staged already, you can pass the -–staged option to git diff (in pre-1.6 versions of Git, use –-cached).

git diff --staged
git diff --cached

FATAL ERROR: Ineffective mark-compacts near heap limit Allocation failed - JavaScript heap out of memory in ionic 3

same issue on centos server 7, but this solved my problem:

node --max-old-space-size=X node_modules/@angular/cli/bin/ng build --prod

Where X = (2048 or 4096 or 8192 o..) is the value of memory

REST / SOAP endpoints for a WCF service

You can expose the service in two different endpoints. the SOAP one can use the binding that support SOAP e.g. basicHttpBinding, the RESTful one can use the webHttpBinding. I assume your REST service will be in JSON, in that case, you need to configure the two endpoints with the following behaviour configuration

  <behavior name="jsonBehavior">

An example of endpoint configuration in your scenario is

  <service name="TestService">
    <endpoint address="soap" binding="basicHttpBinding" contract="ITestService"/>
    <endpoint address="json" binding="webHttpBinding"  behaviorConfiguration="jsonBehavior" contract="ITestService"/>

so, the service will be available at

Apply [WebGet] to the operation contract to make it RESTful. e.g.

public interface ITestService
   string HelloWorld(string text)

Note, if the REST service is not in JSON, parameters of the operations can not contain complex type.

Reply to the post for SOAP and RESTful POX(XML)

For plain old XML as return format, this is an example that would work both for SOAP and XML.

[ServiceContract(Namespace = "http://test")]
public interface ITestService
    [WebGet(UriTemplate = "accounts/{id}")]
    Account[] GetAccount(string id);

POX behavior for REST Plain Old XML

<behavior name="poxBehavior">


  <service name="TestService">
    <endpoint address="soap" binding="basicHttpBinding" contract="ITestService"/>
    <endpoint address="xml" binding="webHttpBinding"  behaviorConfiguration="poxBehavior" contract="ITestService"/>

Service will be available at

REST request try it in browser,

SOAP request client endpoint configuration for SOAP service after adding the service reference,

    <endpoint address="" binding="basicHttpBinding"
      contract="ITestService" name="BasicHttpBinding_ITestService" />

in C#

TestServiceClient client = new TestServiceClient();

Another way of doing it is to expose two different service contract and each one with specific configuration. This may generate some duplicates at code level, however at the end of the day, you want to make it working.

Change HTML email body font type and size in VBA

Set texts with different sizes and styles, and size and style for texts from cells ( with Range)

Sub EmailManuellAbsenden()

Dim ghApp As Object
Dim ghOldBody As String
Dim ghNewBody As String

Set ghApp = CreateObject("Outlook.Application")
With ghApp.CreateItem(0)
.To = Range("B2")
.CC = Range("B3")
.Subject = Range("B4")
 ghOldBody = .htmlBody

 ghNewBody = "<font style=""font-family: Calibri; font-size: 11pt;""/font>" & _
 "<font style=""font-family: Arial; font-size: 14pt;"">Arial Text 14</font>" & _
 Range("B5") & "<br>" & _
 Range("B6") & "<br>" & _
 "<font style=""font-family: Chiller; font-size: 21pt;"">Ciller 21</font>" &
 .htmlBody = ghNewBody & ghOldBody

 End With

End Sub
'Fill B2 to B6 with some letters for testing
'"<font style=""font-family: Calibri; font-size: 15pt;""/font>" = works for all Range Objekts

angular.js ng-repeat li items with html content

ng-bind-html-unsafe is deprecated from 1.2. The correct answer should be currently:

HTML-side: (the same as the accepted answer stated):

<div ng-app ng-controller="MyCtrl">
      <li ng-repeat=" opt in opts" ng-bind-html-unsafe="opt.text">
        {{ opt.text }}


But in the controller-side:

myApp.controller('myCtrl', ['$scope', '$sce', function($scope, $sce) {
// ...
   $ { 
      opt = $sce.trustAsHtml(opt);

What is git fast-forwarding?

When you try to merge one commit with a commit that can be reached by following the first commit’s history, Git simplifies things by moving the pointer forward because there is no divergent work to merge together – this is called a “fast-forward.”

For more :

In another way,

If Master has not diverged, instead of creating a new commit, git will just point master to the latest commit of the feature branch. This is a “fast forward.”

There won't be any "merge commit" in fast-forwarding merge.

Why do we use Base64?

Base64 instead of escaping special characters

I'll give you a very different but real example: I write javascript code to be run in a browser. HTML tags have ID values, but there are constraints on what characters are valid in an ID.

But I want my ID to losslessly refer to files in my file system. Files in reality can have all manner of weird and wonderful characters in them from exclamation marks, accented characters, tilde, even emoji! I cannot do this:

<div id="/path/to/my_strangely_named_file!@().jpg">
    <img src="!@().jpg">
    Here's a pic I took in Moscow.

Suppose I want to run some code like this:


I think this code will fail when executed.

With Base64 I can refer to something complicated without worrying about which language allows what special characters and which need escaping:


Unlike using an MD5 or some other hashing function, you can reverse the encoding to find out what exactly the data was that actually useful.

I wish I knew about Base64 years ago. I would have avoided tearing my hair out with ‘encodeURIComponent’ and str.replace(‘\n’,’\\n’)

SSH transfer of text:

If you're trying to pass complex data over ssh (e.g. a dotfile so you can get your shell personalizations), good luck doing it without Base 64. This is how you would do it with base 64 (I know you can use SCP, but that would take multiple commands - which complicates key bindings for sshing into a server):

Greater than less than, python

Check to make sure that both score and array[x] are numerical types. You might be comparing an integer to a string...which is heartbreakingly possible in Python 2.x.

>>> 2 < "2"
>>> 2 > "2"
>>> 2 == "2"


Further explanation: How does Python compare string and int?

OVER_QUERY_LIMIT in Google Maps API v3: How do I pause/delay in Javascript to slow it down?

Here I have loaded 2200 markers. It takes around 1 min to add 2200 locations.

//function to get random element from an array
    (function($) {
        $.rand = function(arg) {
            if ($.isArray(arg)) {
                return arg[$.rand(arg.length)];
            } else if (typeof arg === "number") {
                return Math.floor(Math.random() * arg);
            } else {
                return 4;  // chosen by fair dice roll

//start code on document ready
$(document).ready(function () {
    var map;
    var elevator;
    var myOptions = {
        zoom: 0,
        center: new google.maps.LatLng(35.392738, -100.019531), 
        mapTypeId: google.maps.MapTypeId.ROADMAP
    map = new google.maps.Map($('#map_canvas')[0], myOptions);

    //get place from inputfile.js
    var placesObject = place;
    errorArray = [];

  //will fire 20 ajax request at a time and other will keep in queue
    var queuCounter = 0, setLimit = 20; 

  //keep count of added markers and update at top
  totalAddedMarkers = 0;

  //make an array of geocode keys to avoid the overlimit error
    var geoCodKeys = [

  //funciton to add marker
    var addMarkers = function(address, queKey){
        var key = jQuery.rand(geoCodKeys);
        var url = ''+key+'&address='+address+'&sensor=false';

        var qyName = '';
        if( queKey ) {
            qyName = queKey;
        } else {
            qyName = 'MyQueue'+queuCounter;

        $.ajaxq (qyName, {
            url: url,
            dataType: 'json'
        }).done(function( data ) {
                    var address = getParameterByName('address', this.url);
                    var index = errorArray.indexOf(address);
                        var p = data.results[0].geometry.location;
                        var latlng = new google.maps.LatLng(, p.lng);
                        new google.maps.Marker({
                            position: latlng,
                            map: map
                        totalAddedMarkers ++;

            //update adde marker count
                        if (index > -1) {
                            errorArray.splice(index, 1);
                        if(data.status = 'ZERO_RESULTS')
                            return false;

            //on error call add marker function for same address
            //and keep in Error ajax queue
                        addMarkers( address, 'Errror' );
                        if (index == -1) {
                            errorArray.push( address );

    //mentain ajax queue set
        if( queuCounter == setLimit ){
            queuCounter = 0;

  //function get url parameter from url string
    getParameterByName = function ( name,href )
      name = name.replace(/[\[]/,"\\\[").replace(/[\]]/,"\\\]");
      var regexS = "[\\?&]"+name+"=([^&#]*)";
      var regex = new RegExp( regexS );
      var results = regex.exec( href );
      if( results == null )
        return "";
        return decodeURIComponent(results[1].replace(/\+/g, " "));

  //call add marker function for each address mention in inputfile.js
    for (var x = 0; x < placesObject.length; x++) {
        var address = placesObject[x]['City'] + ', ' + placesObject[x]['State'];

EntityType has no key defined error

You don't have to use key attribute all the time. Make sure the mapping file properly addressed the key

this.HasKey(t => t.Key);
this.Property(p => p.Key)

and don't forget to add the mapping in the Repository's OnModelCreating

modelBuilder.Configurations.Add(new PacketHistoryMap());

How can I check what version/edition of Visual Studio is installed programmatically?

if somebody needs C# example then:

var registry = Registry.ClassesRoot;
var subKeyNames = registry.GetSubKeyNames();
var regex = new Regex(@"^VisualStudio\.edmx\.(\d+)\.(\d+)$");
foreach (var subKeyName in subKeyNames)
    var match = regex.Match(subKeyName);
    if (match.Success)
        Console.WriteLine("V" + match.Groups[1].Value + "." + match.Groups[2].Value);

Failed to resolve:

28.0.0 is the final version of support libraries. Android has migrated to AndroidX. To use the latest android libraries, Migrating to AndroidX

Edit: Versions 28.0.0-rc02 and 28.0.0 are now available.

I don't see any 28.0 version on Google Maven. Only 28.0.0-alpha1 and 28.0.0-alpha3. Just change it to either of those or how it was previously, i.e., with .+ which just means any version under 28 major release.

For an alpha appcompat release 28.+ makes more sense.

Could not reserve enough space for object heap

Suppose your class is called Test in package mypackage. Run your code like this:

java -Xmx1024m mypackage.Test

This will reserve 1024 MB of heap space for your code. If you want 512 MB, you can use:

java -Xmx512m mypackage.Test

Use little m in 1024m, 512m, etc

Set Locale programmatically

I had a problem with setting locale programmatically with devices that has Android OS N and higher. For me the solution was writing this code in my base activity:

(if you don't have a base activity then you should make these changes in all of your activities)

protected void attachBaseContext(Context base) {

private Context updateBaseContextLocale(Context context) {
    String language = SharedPref.getInstance().getSavedLanguage();
    Locale locale = new Locale(language);

    if (Build.VERSION.SDK_INT >= Build.VERSION_CODES.N) {
        return updateResourcesLocale(context, locale);

    return updateResourcesLocaleLegacy(context, locale);

private Context updateResourcesLocale(Context context, Locale locale) {
    Configuration configuration = context.getResources().getConfiguration();
    return context.createConfigurationContext(configuration);

private Context updateResourcesLocaleLegacy(Context context, Locale locale) {
    Resources resources = context.getResources();
    Configuration configuration = resources.getConfiguration();
    configuration.locale = locale;
    resources.updateConfiguration(configuration, resources.getDisplayMetrics());
    return context;

note that here it is not enough to call


you also need to get the context that this method returns and then to set this context in the attachBaseContext method.

How to extract a substring using regex

as in javascript:


the actual regexp is: /'([^']+)'/

if you use the non greedy modifier (as per another post) it's like this:


it is cleaner.

CSS "color" vs. "font-color"

I would think that one reason could be that the color is applied to things other than font. For example:

div {
    border: 1px solid;
    color: red;

Yields both a red font color and a red border.

Alternatively, it could just be that the W3C's CSS standards are completely backwards and nonsensical as evidenced elsewhere.

Hashmap does not work with int, char

Hashmaps can only use classes, not primitives. This page from might be of use in guiding you to finding the answer. To be honest, I haven't figured out the answer to this problem in detail myself.

What is JavaScript's highest integer value that a number can go to without losing precision?

I did a simple test with a formula, X-(X+1)=-1, and the largest value of X I can get to work on Safari, Opera and Firefox (tested on OS X) is 9e15. Here is the code I used for testing:

javascript: alert(9e15-(9e15+1));

Allow scroll but hide scrollbar

Try this:


<div id="container">
    <div id="content">
        // Content here


    height: 100%;
    width: 100%;
    overflow: hidden;

    width: 100%;
    height: 99%;
    overflow: auto;
    padding-right: 15px;

html, body{
    height: 99%;

JSFiddle Demo

Tested on FF and Safari.

PowerShell script to return members of multiple security groups

Get-ADGroupMember "Group1" -recursive | Select-Object Name | Export-Csv c:\path\Groups.csv

I got this to work for me... I would assume that you could put "Group1, Group2, etc." or try a wildcard. I did pre-load AD into PowerShell before hand:

Get-Module -ListAvailable | Import-Module

How can I increase a scrollbar's width using CSS?

This can be done in WebKit-based browsers (such as Chrome and Safari) with only CSS:

::-webkit-scrollbar {
    width: 2em;
    height: 2em
::-webkit-scrollbar-button {
    background: #ccc
::-webkit-scrollbar-track-piece {
    background: #888
::-webkit-scrollbar-thumb {
    background: #eee

JSFiddle Demo


Extracting hours from a DateTime (SQL Server 2005)

you must use datepart()


datepart(hour , getdate())

Chrome disable SSL checking for sites?

To disable the errors windows related with certificates you can start Chrome from console and use this option: --ignore-certificate-errors.

"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe" --ignore-certificate-errors

You should use it for testing purposes. A more complete list of options is here:

How can I hide the Android keyboard using JavaScript?

Giving soft keyboard some time to close works for me.

$('#ButtonCancel').click(function () {

    setTimeout(function () {
        //close the dialog, switch to another screen, etc.
    }, 300);

Convert multidimensional array into single array

none of answers helped me, in case when I had several levels of nested arrays. the solution is almost same as @AlienWebguy already did, but with tiny difference.

function nestedToSingle(array $array)
    $singleDimArray = [];

    foreach ($array as $item) {

        if (is_array($item)) {
            $singleDimArray = array_merge($singleDimArray, nestedToSingle($item));

        } else {
            $singleDimArray[] = $item;

    return $singleDimArray;

test example

$array = [

    $array = nestedToSingle($array);

    array:12 [
        0 => "first"
        1 => "second"
        2 => "third"
        3 => "fourth"
        4 => "fifth"
        5 => "sixth"
        6 => "seventh"
        7 => "eighth"
        8 => "ninth"
        9 => "tenth"
        10 => "eleventh"
        11 => "twelfth"

How to cat <<EOF >> a file containing code?

This should work, I just tested it out and it worked as expected: no expansion, substitution, or what-have-you took place.

cat <<< '
curr=`cat /sys/class/backlight/intel_backlight/actual_brightness`
if [ $curr -lt 4477 ]; then
  echo $curr  > /sys/class/backlight/intel_backlight/brightness;
fi' > file # use overwrite mode so that you don't keep on appending the same script to that file over and over again, unless that's what you want. 

Using the following also works.

cat <<< ' > file
 ... code ...'

Also, it's worth noting that when using heredocs, such as << EOF, substitution and variable expansion and the like takes place. So doing something like this:

cat << EOF > file
cd "$HOME"
echo "$PWD" # echo the current path

will always result in the expansion of the variables $HOME and $PWD. So if your home directory is /home/foobar and the current path is /home/foobar/bin, file will look like this:

cd "/home/foobar"
echo "/home/foobar/bin"

instead of the expected:

cd "$HOME"
echo "$PWD"

Refused to display in a frame because it set 'X-Frame-Options' to 'SAMEORIGIN'

I was having the same issue implementing in Angular 9. These are the two steps I did:

  1. Change your YouTube URL from to

  2. And then pass the URL through DomSanitizer of Angular.

    import { Component, OnInit } from "@angular/core";
    import { DomSanitizer } from '@angular/platform-browser';
      selector: "app-help",
      templateUrl: "./help.component.html",
      styleUrls: ["./help.component.scss"],
    export class HelpComponent implements OnInit {
      youtubeVideoLink: any = ''
      constructor(public sanitizer: DomSanitizer) {
        this.sanitizer = sanitizer;   
      ngOnInit(): void {}
        return this.sanitizer.bypassSecurityTrustResourceUrl(this.youtubeVideoLink);
    <iframe width="420" height="315" [src]="getLink()" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>

How to rename with prefix/suffix?

In my case I have a group of files which needs to be renamed before I can work with them. Each file has its own role in group and has its own pattern.

As result I have a list of rename commands like this:

f=`ls *canctn[0-9]*`   ;  mv $f  CNLC.$f
f=`ls *acustb[0-9]*`   ;  mv $f  CATB.$f
f=`ls *accusgtb[0-9]*` ;  mv $f  CATB.$f
f=`ls *acus[0-9]*`     ;  mv $f  CAUS.$f

Try this also :

f=MyFileName; mv $f {pref1,pref2}$f{suf1,suf2}

This will produce all combinations with prefixes and suffixes:


Another way to solve same problem is to create mapping array and add corespondent prefix for each file type as shown below:

unset masks
typeset -A masks
for fileMask in ${!masks[*]}; 
[ -e ${fileName} ] &&  mv ${fileName} ${registryEntry}.${fileName}  

How can I get my webapp's base URL in ASP.NET MVC?

This is working in ASP .NET MVC 4 In any controller action you can write: 1stline gets the whole url+Query String. 2nd line remove local path & query ,last '/' symbol. 3rd line add '/' symbol at last position.

Uri url = System.Web.HttpContext.Current.Request.Url;
string UrlLink = url.OriginalString.Replace(url.PathAndQuery,"");
UrlLink = String.Concat(UrlLink,"/" );

Spring: how do I inject an HttpServletRequest into a request-scoped bean?

As suggested here you can also inject the HttpServletRequest as a method param, e.g.:

public MyResponseObject myApiMethod(HttpServletRequest request, ...) {

Passing parameter to controller action from a Html.ActionLink

Addition to the accepted answer:

if you are going to use

 @Html.ActionLink("LinkName", "ActionName", "ControllerName", new { @id = idValue, @secondParam= = 2 },null)

this will create actionlink where you can't create new custom attribute or style for the link.

However, the 4th parameter in ActionLink extension will solve that problem. Use the 4th parameter for customization in your way.

 @Html.ActionLink("LinkName", "ActionName", "ControllerName", new { @id = idValue, @secondParam= = 2 }, new { @class = "btn btn-info", @target = "_blank" })

Oracle 12c Installation failed to access the temporary location

The error is caused due to administrative shares are being disabled. If they cannot be enabled then perform the following workaround:

6.2.23 INS-30131 Error When Installing Oracle Database or Oracle Client

If the administrative shares are not enabled when performing a single instance Oracle Database or Oracle Client installation for 12c Release 1 (12.1) on Microsoft Windows 7, Microsoft Windows 8, and Microsoft Windows 10, then the installation fails with an INS-30131 error.


Execute the net share command to ensure that the administrative shares are enabled. If they are disabled, then enable them by following the instructions in the Microsoft Windows documentation. Alternatively, perform the client or server installation by specifying the following options:

  • For a client installation:

    -ignorePrereq -J"-Doracle.install.client.validate.clientSupportedOSCheck=false"

  • For a server installation:

    -ignorePrereq -J"-Doracle.install.db.validate.supportedOSCheck=false"

This issue is tracked with Oracle bug 21452473.

Source: Oracle Database Release Notes (Section 6.2.23)

How can I send an HTTP POST request to a server from Excel using VBA?

In addition to the anwser of Bill the Lizard:

Most of the backends parse the raw post data. In PHP for example, you will have an array $_POST in which individual variables within the post data will be stored. In this case you have to use an additional header "Content-type: application/x-www-form-urlencoded":

Set objHTTP = CreateObject("WinHttp.WinHttpRequest.5.1")
URL = ""
objHTTP.Open "POST", URL, False
objHTTP.setRequestHeader "User-Agent", "Mozilla/4.0 (compatible; MSIE 6.0; Windows NT 5.0)"
objHTTP.setRequestHeader "Content-type", "application/x-www-form-urlencoded"
objHTTP.send ("var1=value1&var2=value2&var3=value3")

Otherwise you have to read the raw post data on the variable "$HTTP_RAW_POST_DATA".

How to add new column to an dataframe (to the front not end)?

Use cbind e.g.

df <- data.frame(b = runif(6), c = rnorm(6))
cbind(a = 0, df)


> cbind(a = 0, df)
  a         b          c
1 0 0.5437436 -0.1374967
2 0 0.5634469 -1.0777253
3 0 0.9018029 -0.8749269
4 0 0.1649184 -0.4720979
5 0 0.6992595  0.6219001
6 0 0.6907937 -1.7416569