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How to declare std::unique_ptr and what is the use of it?
... way.
Smart pointers are supposed to model object ownership, and automatically take care of destroying the pointed object when the last (smart, owning) pointer to that object falls out of scope.
This way you do not have to remember doing delete on objects allocated dynamically - the destructor o...
Java: Calling a super method which calls an overridden method
...
The keyword super doesn't "stick". Every method call is handled individually, so even if you got to SuperClass.method1() by calling super, that doesn't influence any other method call that you might make in the future.
That means there is no direct way to call SuperClass....
Calling parent class __init__ with multiple inheritance, what's the right way?
...sing super() leads to greater flexibility for subclasses.
In the direct call approach, C.__init__ can call both A.__init__ and B.__init__.
When using super(), the classes need to be designed for cooperative multiple inheritance where C calls super, which invokes A's code which will also call sup...
Check if a row exists, otherwise insert
...row for each flight? If so:
IF EXISTS (SELECT * FROM Bookings WHERE FLightID = @Id)
BEGIN
--UPDATE HERE
END
ELSE
BEGIN
-- INSERT HERE
END
I assume what I said, as your way of doing things can overbook a flight, as it will insert a new row when there are 10 tickets max and you are booking 2...
Are Java static calls more or less expensive than non-static calls?
...ke any difference. Hotspot may choose to optimize in ways that make static calls faster for one method, non-static calls faster for another.
Third: much of the mythos surrounding static versus non-static are based either on very old JVMs (which did not do anywhere near the optimization that Hotspot...
How do you post to an iframe?
...some clever ninja hack; although it was deprecated (and therefore won't validate) in HTML 4 Strict or XHTML 1 Strict, it's been part of HTML since 3.2, it's formally part of HTML5, and it works in just about every browser since Netscape 3.
I have verified this behaviour as working with XHTML 1 Stri...
How can I convert an image into Base64 string using JavaScript?
...);
var dataURL;
canvas.height = this.naturalHeight;
canvas.width = this.naturalWidth;
ctx.drawImage(this, 0, 0);
dataURL = canvas.toDataURL(outputFormat);
callback(dataURL);
};
img.src = src;
if (img.complete || img.complete === undefined) {
img.src = "dat...
What is a callback function?
What is a callback function?
21 Answers
21
...
How do I detect a click outside an element?
...completely when a user clicks on the head of these menus. I would like to hide these elements when the user clicks outside the menus' area.
...
How to get jQuery dropdown value onchange event
...
If you have simple dropdown like:
<select name="status" id="status">
<option value="1">Active</option>
<option value="0">Inactive</option>
</select>
Then you can use this code for getting value:
$(function(){
$("#status").change(functi...