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Why should the copy constructor accept its parameter by reference in C++?
... reference, it's by value. To do that you make a copy, and to do that you call the copy constructor. But to do that, we need to make a new value, so we call the copy constructor, and so on...
(You would have infinite recursion because "to make a copy, you need to make a copy".)
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Whether a variable is undefined [duplicate]
...ver return 'undefined' for an empty selection. It always returns an empty string (i.e. ""). .html() will return null if the element doesn't exist though.You need to do:
if(page_name != '')
For other variables that don't come from something like jQuery.val() you would do this though:
if(typeof ...
Can I see changes before I save my file in Vim?
...t=nofile bh=wipe nobl noswf ro ft=" . filetype
endfunction
com! DiffSaved call s:DiffWithSaved()
To get out of diff view you can use the :diffoff command.
Below is a similar function, adapted to mimic the 'cvs diff' command...
...
how do i block or restrict special characters from input fields with jquery?
...tion (event) {
var regex = new RegExp("^[a-zA-Z0-9]+$");
var key = String.fromCharCode(!event.charCode ? event.which : event.charCode);
if (!regex.test(key)) {
event.preventDefault();
return false;
}
});
...
How to convert NSNumber to NSString
So I have an NSArray "myArray" with NSNumber s and NSString s. I need them in another UIView so i go like this:
7 Ans...
What is the yield keyword used for in C#?
...r()
{
foreach(int i in Integers())
{
Console.WriteLine(i.ToString());
}
}
public IEnumerable<int> Integers()
{
yield return 1;
yield return 2;
yield return 4;
yield return 8;
yield return 16;
yield return 16777216;
}
When you step through the exam...
Using current time in UTC as default value in PostgreSQL
...
Correction: The 'utc' string must also be single-quoted, not double-quoted.
– code_dredd
Nov 22 '19 at 1:11
add a comment
...
How do I group Windows Form radio buttons?
...ifies which RadioButton controls are mutually exclusive.")]
public string GroupName { get; set; }
protected override void OnCheckedChanged(EventArgs e)
{
base.OnCheckedChanged(e);
if (Checked)
{
var arbControls = (dynamic)...
How do I parse a URL query parameters, in Javascript? [duplicate]
In Javascript, how can I get the parameters of a URL string (not the current URL)?
2 Answers
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What's the best way to cancel event propagation between nested ng-click calls?
... in it. Clicking the black overlay dismisses it; clicking the image will call a function that shows the next image.
9 Answ...