First and foremost, the “pass by value vs. pass by reference” distinction as defined in the CS theory is now obsolete because the technique originally defined as “pass by reference” has since fallen out of favor and is seldom used now.1 Newer languages2 tend to use a different (but similar) pair of techniques to achieve … Read more
Breadth vs Depth; think in terms of a tree of references with your object as the root node. Shallow: The variables A and B refer to different areas of memory, when B is assigned to A the two variables refer to the same area of memory. Later modifications to the contents of either are instantly … Read more
I often have several statements at the start of a method to return for “easy” situations. For example, this: public void DoStuff(Foo foo) { if (foo != null) { … } } … can be made more readable (IMHO) like this: public void DoStuff(Foo foo) { if (foo == null) return; … } So yes, … Read more
Tries, also known as prefix-trees or crit-bit trees, have existed for over 40 years but are still relatively unknown. A very cool use of tries is described in “TRASH – A dynamic LC-trie and hash data structure”, which combines a trie with a hash function.
Developers are often confused by what a callback is because of the name of the damned thing. A callback function is a function which is: accessible by another function, and is invoked after the first function if that first function completes A nice way of imagining how a callback function works is that it is … Read more
Another one from xkcd
There are some wonderful answers on here to this questions that get into all sorts of great detail about interfaces and loosely coupling code, inversion of control and so on. There are some fairly heady discussions, so I’d like to take the opportunity to break things down a bit for understanding why an interface is … Read more
In C, arrays can be indexed like so: a[10] which is very common. However, the lesser known form (which really does work!) is: 10[a] which means the same as the above.
In computing, an idempotent operation is one that has no additional effect if it is called more than once with the same input parameters. For example, removing an item from a set can be considered an idempotent operation on the set. In mathematics, an idempotent operation is one where f(f(x)) = f(x). For example, the … Read more
Concurrency is when two or more tasks can start, run, and complete in overlapping time periods. It doesn’t necessarily mean they’ll ever both be running at the same instant. For example, multitasking on a single-core machine. Parallelism is when tasks literally run at the same time, e.g., on a multicore processor. Quoting Sun’s Multithreaded Programming … Read more