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The difference between bracket [ ] and double bracket [[ ]] for accessing the elements of a list or
...urn the ith sequential element of x.
For lists, one generally uses [[ to select any single element, whereas [ returns a list of the selected elements.
The [[ form allows only a single element to be selected using integer or character indices, whereas [ allows indexing by vectors. Note though tha...
What is a “surrogate pair” in Java?
... does not support UTF-32
"????".equals("\u1F309") // false
3. You can convert Unicode character to Java String
"????".equals(new String(Character.toChars(0x0001F309))) //true
4. String.substring() does not consider supplementary characters
"????????".substring(0,1) //"?"
"????????".substri...
Hosting ASP.NET in IIS7 gives Access is denied?
..., nothing worked except the following, which solved the problem: open IIS, select the site, open Authentication (in the IIS section), right click Anonymous Authentication and select Edit, select Application Pool Identity.
sh...
Remove empty lines in text using Visual Studio
...t + T + O
Under Environment tab > Keyboard
Search for "DeleteBlank" and select Edit.DeleteBlankLines
Add a new shortcut for example Ctrl+D,Ctrl+E
Assign > OK
select all text and hit the shortcut
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How do you truncate all tables in a database using TSQL?
...'
EXEC sp_MSforeachtable 'SET QUOTED_IDENTIFIER ON';
IF NOT EXISTS (
SELECT
*
FROM
SYS.IDENTITY_COLUMNS
JOIN SYS.TABLES ON SYS.IDENTITY_COLUMNS.Object_ID = SYS.TABLES.Object_ID
WHERE
SYS.TABLES.Object_ID = OBJECT_ID('?') AND SYS.IDENTITY_COLUMNS.Last_Val...
How do I use installed packages in PyCharm?
...er's path. It will bring up a short drop-down menu, from which you should select "More..". On the right hand side of the new pop-up, there will be an icon with the mouse-over text of "Show paths for the selected interpreter". Click that button. This new 'Interpreter Paths' pop-up is where you ca...
live output from subprocess command
...ptimization: If we are only using one pipe, or no pipe at
# all, using select() or threads is unnecessary.
if [self.stdin, self.stdout, self.stderr].count(None) >= 2:
But, alas, here we've made at least two, and maybe three, different pipes, so the count(None) returns either 1 or 0. We...
How do I alter the position of a column in a PostgreSQL database table?
... tablename (column defs go here);
insert into tablename (col1, col2, col3) select col1, col2, col3 from oldtable;
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How to get the number of characters in a std::string?
...ng length
std::cout << strlen(str.c_str()) << std::endl; // convert C++ string to C-string then call strlen
return 0;
}
Output:
6
6
6
6
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What is SQL injection? [duplicate]
...ue for any language), which might be used to handle a user login.
$sql = "SELECT FROM users WHERE username='".$_GET['username']."' AND password='".$_GET['password']."'";
The harm is done when the user enters something like
administrator'; --
... for the username. Without proper encoding the...