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What are the different usecases of PNG vs. GIF vs. JPEG vs. SVG?
...types of compression: Lossless and Lossy.
Lossless means that the image is made smaller, but at no detriment to the quality.
Lossy means the image is made (even) smaller, but at a detriment to the quality. If you saved an image in a Lossy format over and over, the image quality would get progres...
Type List vs type ArrayList in Java [duplicate]
I understand that with (1), implementations of the List interface can be swapped. It seems that (1) is typically used in an application regardless of need (myself I always use this).
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For-each over an array in JavaScript
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forEach accepts a callback function and, optionally, a value to use as this when calling that callback (not used above). The callback is called for each entry in the array, in order, skipping non-existent entries in sparse arrays. Although I only used one argument above, the callback is called wit...
Const before or const after?
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why is there two correct ways of specifying const data and in what situation would you prefer or need one over the other if any?
Essentially, the reason that the position of const within specifiers prior to an asterisk does not...
What's the point of OOP?
...rstand principles such as LSP); there seems to be little uniformity or consistency to the approaches that people take to modelling problem domains. All too often, the class is used simply for its syntactic sugar; it puts the functions for a record type into their own little namespace.
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What is java interface equivalent in Ruby?
...you have to be careful not to conflate the concept of the Interface, which is an abstract specification of the responsibilities, guarantees and protocols of a unit with the concept of the interface which is a keyword in the Java, C# and VB.NET programming languages. In Ruby, we use the former all th...
What is the fastest way to check if a class has a function defined?
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Yes, use getattr() to get the attribute, and callable() to verify it is a method:
invert_op = getattr(self, "invert_op", None)
if callable(invert_op):
invert_op(self.path.parent_op)
Note that getattr() normally throws exception when the attribute doesn't exist. However, if you specify a...
Why does Python code run faster in a function?
This piece of code in Python runs in (Note: The timing is done with the time function in BASH in Linux.)
3 Answers
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What is a “callback” in C and how are they implemented?
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There is no "callback" in C - not more than any other generic programming concept.
They're implemented using function pointers. Here's an example:
void populate_array(int *array, size_t arraySize, int (*getNextValue)(void))
{
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Does Javascript pass by reference? [duplicate]
Does Javascript pass by references or pass by values? Here is an example from Javascript: The Good Parts . I am very confused about my parameter for the rectangle function. It is actually undefined , and redefined inside the function. There are no original reference. If I remove it from the func...