clone

As far as I can tell, there are two ways of copying a bitmap. Bitmap.Clone() Bitmap A = new Bitmap("somefile.png"); Bitmap B = (Bitmap)A.Clone(); new Bitmap() Bitmap A = new Bitmap("somefile.png"); Bitmap B = new Bitmap(A); How do these approaches differ? I'm particularly interested in the difference in terms of memory and threading. It is the common difference between a "deep" and a "shallow" copy, also an issue with the almost-deprecated IClonable interface. The Clone() method creates a new Bitmap object but the pixel data is shared with the original bitmap object. The Bitmap(Image)

If I invoke clone() method on array of Objects of type A, how will it clone its elements? Will the copy be referencing to the same objects? Or will it call (element of type A).clone() for each of them? Bozho clone() creates a shallow copy. Which means the elements will not be cloned. (What if they didn't implement Cloneable ?) You may want to use Arrays.copyOf(..) for copying arrays instead of clone() (though cloning is fine for arrays, unlike for anything else) If you want deep cloning, check this answer A little example to illustrate the shallowness of clone() even if the elements are

Is there any way to create a deep copy of a canvas element with all drawn content? Actually the correct way to copy the canvas data is to pass the old canvas to the new blank canvas. Try this function. function cloneCanvas(oldCanvas) { //create a new canvas var newCanvas = document.createElement('canvas'); var context = newCanvas.getContext('2d'); //set dimensions newCanvas.width = oldCanvas.width; newCanvas.height = oldCanvas.height; //apply the old canvas to the new one context.drawImage(oldCanvas, 0, 0); //return the new canvas return newCanvas; } Using getImageData is for pixel data access

It appears that in PHP objects are passed by reference. Even assignment operators do not appear to be creating a copy of the Object. Here's a simple, contrived proof: <?php class A { public $b; } function set_b($obj) { $obj->b = "after"; } $a = new A(); $a->b = "before"; $c = $a; //i would especially expect this to create a copy. set_b($a); print $a->b; //i would expect this to show 'before' print $c->b; //i would ESPECIALLY expect this to show 'before' ?> In both print cases I am getting 'after' So, how do I pass $a to set_b() by value, not by reference? In PHP 5+ objects are passed by