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Java Generics (Wildcards)
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In your first question, <? extends T> and <? super T> are examples of bounded wildcards. An unbounded wildcard looks like <?>, and basically means <? extends Object>. It loosely means the generic can be any type. A bounded wildcard (<? ext...
Using a 'using alias = class' with generic types? [duplicate]
... A using alias directive cannot have an open generic type on the right hand side. For example, you cannot create a using alias for a List<T>, but you can create one for a List<int>. msdn.microsoft.com/en-us/library/sf0df423.aspx
– Sergey Mirvoda
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List passed by ref - help me explain this behaviour
...e value of the variable (i.e. the reference - think "pointer") is copied - and changes to the value of the parameter inside ChangeList aren't seen by TestMethod.
try:
private void ChangeList(ref List<int> myList) {...}
...
ChangeList(ref myList);
This then passes a reference to the local-v...
Should arrays be used in C++?
Since std::list and std::vector exist, is there a reason to use traditional C arrays in C++, or should they be avoided, just like malloc ?
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Immutable vs Mutable types
... changing what the variable refers to. A mutable type can change that way, and it can also change "in place".
Here is the difference.
x = something # immutable type
print x
func(x)
print x # prints the same thing
x = something # mutable type
print x
func(x)
print x # might print something differe...
Difference between signed / unsigned char [duplicate]
So I know that the difference between a signed int and unsigned int is that a bit is used to signify if the number if positive or negative, but how does this apply to a char ? How can a character be positive or negative?
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Select n random rows from SQL Server table
...th about 50,000 rows in it. I want to select about 5,000 of those rows at random. I've thought of a complicated way, creating a temp table with a "random number" column, copying my table into that, looping through the temp table and updating each row with RAND() , and then selecting from that table...
PHP's array_map including keys
...er call to array_map therefore produces an array of arrays. This then gets converted back to a single-dimension array by array_column.
Usage
$ordinals = [
'first' => '1st',
'second' => '2nd',
'third' => '3rd',
];
$func = function ($k, $v) {
return ['new ' . $k, 'new ' . $v]...
Color different parts of a RichTextBox string
...ox.AppendText(text);
box.SelectionColor = box.ForeColor;
}
}
And this is how you would use it:
var userid = "USER0001";
var message = "Access denied";
var box = new RichTextBox
{
Dock = DockStyle.Fill,
Font = new Font("Courier New", 10...
How do I send a POST request with PHP?
...portant, the CURLOPT_POSTFIELDS parameter data actually doesn't need to be converted to a string ("urlified"). Quote: "This parameter can either be passed as a urlencoded string like 'para1=val1&para2=val2&...' or as an array with the field name as key and field data as value. If value is an...