Tutorial by Topics: pre

A lambda expression is a syntax for creating anonymous functions inline. More formally, from the C# Programming Guide: A lambda expression is an anonymous function that you can use to create delegates or expression tree types. By using lambda expressions, you can write local functions that can ...

Expression Trees are Expressions arranged in a treelike data structure. Each node in the tree is a representation of an expression, an expression being code. An In-Memory representation of a Lambda expression would be an Expression tree, which holds the actual elements (i.e. code) of the query, but ...

Lambda expressions provide a clear and concise way of implementing a single-method interface using an expression. They allow you to reduce the amount of code you have to create and maintain. While similar to anonymous classes, they have no type information by themselves. Type inference needs to happ...

SharedPreferences provide a way to save data to disk in the form of key-value pairs. Context Method public SharedPreferences getSharedPreferences(String name, int mode) Activity Method public SharedPreferences getPreferences() SharedPreferences Methods public SharedPre...

A regular expression is a special sequence of characters that helps in matching or finding other strings or sets of strings, using a specialized syntax held in a pattern. Java has support for regular expression usage through the java.util.regex package. This topic is to introduce and help developers...

List comprehensions in Python are concise, syntactic constructs. They can be utilized to generate lists from other lists by applying functions to each element in the list. The following section explains and demonstrates the use of these expressions. [x + 1 for x in (1, 2, 3)] # list comprehen...

let regex = /pattern/[flags] let regex = new RegExp('pattern', [flags]) let ismatch = regex.test('text') let results = regex.exec('text') FlagsDetailsgglobal. All matches (don't return on the first match).mmulti-line. Causes ^ & $ to match the begin/end of each line (not only begin/e...

For many programmers the regex is some sort of magical sword that they throw to solve any kind of text parsing situation. But this tool is nothing magical, and even though it's great at what it does, it's not a full featured programming language (i.e. it is not Turing-complete). What does 'regu...

WordPress is an open source Content Management System (CMS) which is used to build and manage websites. WordPress is the most popular CMS on the internet by a country mile, powering about half of all CMS websites at time of writing and about a quarter of all websites on the internet. WordPress ...

All preprocessor commands begins with the hash (pound) symbol #. A C macro is just a preprocessor command that is defined using the #define preprocessor directive. During the preprocessing stage, the C preprocessor (a part of the C compiler) simply substitutes the body of the macro wherever its nam...

Express is a minimal and flexible Node.js web application framework, providing a robust set of features for building web applications. The official website of Express is expressjs.com. The source can be found on GitHub. app.get(path [, middleware], callback[, callback...]) app.put(path [, mi...

Python makes regular expressions available through the re module. Regular expressions are combinations of characters that are interpreted as rules for matching substrings. For instance, the expression 'amount\D+\d+' will match any string composed by the word amount plus an integral number, separate...

for {clauses} body for {clauses} yield body for (clauses) body for (clauses) yield body ParameterDetailsforRequired keyword to use a for loop/comprehensionclausesThe iteration and filters over which the for works.yieldUse this if you want to create or 'yield' a collection. Using yield wil...

[[ -OP $filename ]] [[ $file1 -OP $file2 ]] [[ -z $string ]] [[ -n $string ]] [[ "$string1" == "$string2" ]] [[ "$string1" == $pattern ]] The [[ … ]] syntax surrounds bash built-in conditional expressions. Note that spaces are required on either side of th...

WITH QueryName [(ColumnName, ...)] AS (   SELECT ... ) SELECT ... FROM QueryName ...; WITH RECURSIVE QueryName [(ColumnName, ...)] AS (   SELECT ...   UNION [ALL]   SELECT ... FROM QueryName ... ) SELECT ... FROM QueryName ...; Official documentation: WITH clause A Common ...

#define [symbol] // Defines a compiler symbol. #undef [symbol] // Undefines a compiler symbol. #warning [warning message] // Generates a compiler warning. Useful with #if. #error [error message] // Generates a compiler error. Useful with #if. #line [line number] (file name) // Overrides the co...

preg_replace($pattern, $replacement, $subject, $limit = -1, $count = 0); preg_replace_callback($pattern, $callback, $subject, $limit = -1, $count = 0); preg_match($pattern, $subject, &$matches, $flags = 0, $offset = 0); preg_match_all($pattern, $subject, &$matches, $flags = PREG_PATTERN...

The C preprocessor is a simple text parser/replacer that is run before the actual compilation of the code. Used to extend and ease the use of the C (and later C++) language, it can be used for: a. Including other files using #include b. Define a text-replacement macro using #define c. Conditional...