Tutorial by Examples: b

CL-PPCRE:REGISTER-GROUPS-BIND will match a string against a regular expression, and if it matches, bind register groups in the regex to variables. If the string does not match, NIL is returned. (defun parse-date-string (date-string) (cl-ppcre:register-groups-bind (year month day) (...

A pointer to base class can be converted to a pointer to derived class using static_cast. static_cast does not do any run-time checking and can lead to undefined behaviour when the pointer does not actually point to the desired type. struct Base {}; struct Derived : Base {}; Derived d; Base* p1 ...

Say you want to print variables in a 3 character column. Note: doubling { and } escapes them. s = """ pad {{:3}} :{a:3}: truncate {{:.3}} :{e:.3}: combined {{:>3.3}} :{a:>3.3}: {{:3.3}} :{a:3.3}: {{:3.3}} :{c:3...

By default the Large Object Heap is not compacted unlike the classic Object Heap which can lead to memory fragmentation and further, can lead to OutOfMemoryExceptions Starting with .NET 4.5.1 there is an option to explicitly compact the Large Object Heap (along with a garbage collection): GCSettin...

A new pseudo-type dynamic is introduced into the C# type system. It is treated as System.Object, but in addition, any member access (method call, field, property, or indexer access, or a delegate invocation) or application of an operator on a value of such type is permitted without any type checking...

XML <College> <FootBall> <Members>20</Members> <Coach>Archie Theron</Coach> <Name>Wild cats</Name> <StarPlayer>David Perry</StarPlayer> </FootBall> <VolleyBall> <Me...

To create a function which accepts an undetermined number of arguments, there are two methods depending on your environment. 5 Whenever a function is called, it has an Array-like arguments object in its scope, containing all the arguments passed to the function. Indexing into or iterating over th...

XML <Galaxy> <name>Milky Way</name> <CelestialObject name="Earth" type="planet"/> <CelestialObject name="Sun" type="star"/> </Galaxy> XPATH /Galaxy/*[@name] or //*[@name] OUTPUT <CelestialObje...

XML <Galaxy> <name>Milky Way</name> <CelestialObject name="Earth" type="planet"/> <CelestialObject name="Sun" type="star"/> </Galaxy> XPATH /Galaxy/*[@name='Sun'] or //*[@name='Sun'] OUTPUT <C...

XML <Galaxy> <name>Milky Way</name> <CelestialObject name="Earth" type="planet"/> <CelestialObject name="Sun" type="star"/> </Galaxy> XPATH /Galaxy/*[contains(@name,'Ear')] or //*[contains(@name,'Ear...

XML <Galaxy> <name>Milky Way</name> <CelestialObject name="Earth" type="planet"/> <CelestialObject name="Sun" type="star"/> </Galaxy> XPATH /Galaxy/*[contains(lower-case(@name),'ear')] or //*[contain...

XML <Galaxy> <name>Milky Way</name> <CelestialObject name="Earth" type="planet"/> <CelestialObject name="Sun" type="star"/> </Galaxy> XPATH /Galaxy/*[starts-with(lower-case(@name),'ear')] or //*[star...

XML <Galaxy> <name>Milky Way</name> <CelestialObject name="Earth" type="planet"/> <CelestialObject name="Sun" type="star"/> </Galaxy> XPATH /Galaxy/*[ends-with(lower-case(@type),'tar')] or //*[ends-w...

ctrl + alt + shift + / (cmd + alt + shift + / on MacOS) should show you the following dialog: Clicking on Registry you will get The key you want to enable/disable is editor.skip.copy.and.cut.for.empty.selection Tested on Linux Ubuntu and MacOS.

While System.Diagnostics.Contracts is included within the .Net Framework. To use Code Contracts you must install the Visual Studio extensions. Under Extensions and Updates search for Code Contracts then install the Code Contracts Tools After the tools are installed you must enable Code Contract...

To switch the value of two variables you can use tuple unpacking. x = True y = False x, y = y, x x # False y # True

Booleans and other values When dealing with lua it is important to differentiate between the boolean values true and false and values that evaluate to true or false. There are only two values in lua that evaluate to false: nil and false, while everything else, including the numerical 0 evaluate to...

What is a Set? A set is a data structure which contains a set of elements with an important property that no two elements in the set are equal. Types of Set: HashSet: A set backed by a hash table (actually a HashMap instance) Linked HashSet: A Set backed by Hash table and linked list, with pre...

+ dictionaryWithCapacity: Creates and returns a mutable dictionary, initially giving it enough allocated memory to hold a given number of entries. NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithCapacity:1]; NSLog(@"%@",dict); - init Initializes a newly allocated mut...

- removeObjectForKey: Removes a given key and its associated value from the dictionary. NSMutableDictionary *dict = [NSMutableDictionary dictionaryWithDictionary:@{@"key1":@"Easy",@"key2": @"Tutorials"}]; [dict removeObjectForKey:@"key1"]; NSLog...