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String functions perform operations on string values and return either numeric or string values. Using string functions, you can, for example, combine data, extract a substring, compare strings, or convert a string to all uppercase or lowercase characters. CONCAT ( string_value1, string_value...

The Option<T> type is Rust's equivalent of nullable types, without all the issues that come with it. The majority of C-like languages allow any variable to be null if there is no data present, but the Option type is inspired by functional languages which favour 'optionals' (e.g. Ha...

Mongoose is a MongoDB object modeling tool designed to work in an asynchronous environment. Everything in Mongoose starts with a Schema. Each schema maps to a MongoDB collection and defines the shape of the documents within that collection. Mongoose makes it painlessly easy to work with ...

Unlike C/C++, Java is completely endian-neutral with respect to the underlying machine hardware. You do not get big or little endian behavior by default; you have to explicitly specify which behavior you want. The byte type is signed, with the range -128 to +127. To convert a byte value ...

In order to use the Objective-C runtime, you need to import it. #import <objc/objc.h>

React.createClass was deprecated in v15.5 and expected to be removed in v16. There is a drop-in replacement package for those that still require it. Examples using it should be updated.

structure: /* code */ endstructure; When mixing the alternative structure for switch with HTML, it is important to not have any whitespace between the initial switch($condition): and first case $value:. Doing this is attempting to echo something (whitespace) before a case. All control stru...

django-admin commandDetailsmakemigrations <my_app>Generate migrations for my_appmakemigrationsGenerate migrations for all appsmakemigrations --mergeResolve migration conflicts for all appsmakemigrations --merge <my_app>Resolve migration conflicts for my_appmakemigrations --name <migr...

Mirror(reflecting: instance) // Initializes a mirror with the subject to reflect mirror.displayStyle // Display style used for Xcode playgrounds mirror.description // Textual representation of this instance, see CustomStringConvertible mirror.subjectType // Returns the type of the subject being...

funcname = function(paramA, paramB, ...) body; return exprlist end -- a simple function function funcname(paramA, paramB, ...) body; return exprlist end -- shorthand for above local funcname = function(paramA, paramB, ...) body; return exprlist end -- a lambda local funcname; funcname = functio...

Help text can be located before or after the function line, as long as there is not code between the function line and the start of the help text. Capitalization of the function name only bolds the name, and is not required. If a line is prepended with See also, any names on the line that mat...

(function name) ; retrieves the function object of that name #'name ; syntactic sugar for (function name) (symbol-function symbol) ; returns the function bound to symbol (funcall function args...) ; call function with args (apply function arglist) ; call function with arguments given in a list...