Tutorial by Examples: g

Delegates can be used as typed function pointers: class FuncAsParameters { public void Run() { DoSomething(ErrorHandler1); DoSomething(ErrorHandler2); } public bool ErrorHandler1(string message) { Console.WriteLine(message); var shouldWeContinue = ... re...

This is an basic example on how to wire up and make an LED turn on/off when the pushbutton is pressed. /* Basic Digital Read * ------------------ * * turns on and off a light emitting diode(LED) connected to digital * pin 13, when pressing a pushbutton attached to pin 7. It illustrates...

When you want a complete copy of an object (i.e. the object properties and the values inside those properties, etc...), that is called deep cloning. 5.1 If an object can be serialized to JSON, then you can create a deep clone of it with a combination of JSON.parse and JSON.stringify: var existing...

If you want to calculate with BigDecimal you have to use the returned value because BigDecimal objects are immutable: BigDecimal a = new BigDecimal("42.23"); BigDecimal b = new BigDecimal("10.001"); a.add(b); // a will still be 42.23 BigDecimal c = a.add(b); // c will be ...

The Singleton pattern is a design pattern that restricts the instantiation of a class to one object. After the first object is created, it will return the reference to the same one whenever called for an object. var Singleton = (function () { // instance stores a reference to the Singlet...

Module Pattern The Module pattern is a creational and structural design pattern which provides a way of encapsulating private members while producing a public API. This is accomplished by creating an IIFE which allows us to define variables only available in its scope (through closure) while return...

Under the hood, a matrix is a special kind of vector with two dimensions. Like a vector, a matrix can only have one data class. You can create matrices using the matrix function as shown below. matrix(data = 1:6, nrow = 2, ncol = 3) ## [,1] [,2] [,3] ## [1,] 1 3 5 ## [2,] 2 4...

With fixed pattern stri_count_fixed("babab", "b") # [1] 3 stri_count_fixed("babab", "ba") # [1] 2 stri_count_fixed("babab", "bab") # [1] 1 Natively: length(gregexpr("b","babab")[[1]]) # [1] 3 length(gregexpr(...

stri_dup("abc",3) # [1] "abcabcabc" A base R solution that does the same would look like this: paste0(rep("abc",3),collapse = "") # [1] "abcabcabc"

You can specify different application IDs or package names for each buildType or productFlavor using the applicationIdSuffix configuration attribute: Example of suffixing the applicationId for each buildType: defaultConfig { applicationId "com.package.android" minSdkVersion 17 ...

To compare strings alphabetically, use localeCompare(). This returns a negative value if the reference string is lexicographically (alphabetically) before the compared string (the parameter), a positive value if it comes afterwards, and a value of 0 if they are equal. var a = "hello"; va...

A compound view is a custom ViewGroup that's treated as a single view by the surrounding program code. Such a ViewGroup can be really useful in DDD-like design, because it can correspond to an aggregate, in this example, a Contact. It can be reused everywhere that contact is displayed. This means t...

Sometimes, we need to update the progress of the computation done by an AsyncTask. This progress could be represented by a string, an integer, etc. To do this, we have to use two functions. First, we need to set the onProgressUpdate function whose parameter type is the same as the second type parame...

If the user authorizes your application, they will be redirected to the following URL: https://[your registered redirect URI]/#access_token=[an access token] &scope=[authorized scopes] Note that the access token is in the URL fragment and not the query string. This means the value w...

This section provides code and benchmarks for ten unique example implementations which iterate over the entries of a Map<Integer, Integer> and generate the sum of the Integer values. All of the examples have an algorithmic complexity of Θ(n), however, the benchmarks are still useful for provid...

The base package parallel allows parallel computation through forking, sockets, and random-number generation. Detect the number of cores present on the localhost: parallel::detectCores(all.tests = FALSE, logical = TRUE) Create a cluster of the cores on the localhost: parallelCluster <- para...

A major problem with parallelization is the used of RNG as seeds. Random numbers by the number are iterated by the number of operations from either the start of the session or the most recent set.seed(). Since parallel processes arise from the same function, it can use the same seed, possibly causin...

To share your code you create a repository on a remote server to which you will copy your local repository. To minimize the use of space on the remote server you create a bare repository: one which has only the .git objects and doesn't create a working copy in the filesystem. As a bonus you set thi...

Let's say we have the following structure: struct MY_STRUCT { int my_int; float my_float; }; We can define MY_STRUCT to omit the struct keyword so we don't have to type struct MY_STRUCT each time we use it. This, however, is optional. typedef struct MY_STRUCT MY_STRUCT; If we th...

Descriptive names and structure in your code help make comments unnecessary Dim ductWidth As Double Dim ductHeight As Double Dim ductArea As Double ductArea = ductWidth * ductHeight is better than Dim a, w, h a = w * h This is especially helpful when you are copying data from one ...