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Sometimes it's useful to check if a field is present or absent on your JSON to avoid some JSONException on your code. To achieve that, use the JSONObject#has(String) or the method, like on the following example: Sample JSON { "name":"James" } Java code String jsonStr...

Java release naming is a little confusing. There are actually two systems of naming and numbering, as shown in this table: JDK versionMarketing namejdk-1.0JDK 1.0jdk-1.1JDK 1.1jdk-1.2J2SE 1.2......jdk-1.5J2SE 1.5 rebranded Java SE 5jdk-1.6Java SE 6jdk-1.7Java SE 7jdk-1.8Java SE 8jdk-91Java SE 9 (n...

Bootstrap provides multiple classes for styling buttons and making them stand out. Bootstrap buttons can be created by adding the .btn class to an element. Bootstrap ClassRole (color).btn-defaultStandard button (white).btn-primaryProvides extra visual weight and identifies the primary action (blue...

I won't explain what Any and FirstOrDefault does because there are already two good example about them. See Any and First, FirstOrDefault, Last, LastOrDefault, Single, and SingleOrDefault for more information. A pattern I often see in code which should be avoided is if (myEnumerable.Any(t=>t.Fo...

public string GetCustomerNamesCsv() { List<CustomerData> customerDataRecords = GetCustomerData(); // Returns a large number of records, say, 10000+ StringBuilder customerNamesCsv = new StringBuilder(); foreach (CustomerData record in customerDataRecords) { custom...

In order to play a sound using the SoundEffect type, create a variable to hold the loaded sound. Typically this would be an instance variable in the Game class: private SoundEffect mySound; Then, in the LoadContent() method of the Game class: protected override void LoadContent() { // l...

To load a private key directly from disk, use the PEM_read_PrivateKey function: FILE *f; EVP_PKEY *pkey; f = fopen("key.pem", "rb"); PEM_read_PrivateKey( f, /* use the FILE* that was opened */ &pkey, /* pointer to EVP_PKEY structure */ NULL, /* passwor...

In most cases all data that is accessed by several threads should be initialized before the threads are created. This ensures that all threads start with a clear state and no race condition occurs. If this is not possible once_flag and call_once can be used #include <threads.h> #include &lt...

Function composition allows for two functions to operate and be viewed as a single function. Expressed in mathematical terms, given a function f(x) and a function g(x), the function h(x) = f(g(x)). When a function is compiled, it is compiled to a type related to Function1. Scala provides two method...

In JavaScript, the JSON object is used to parse a JSON string. This method is only available in modern browsers (IE8+, Firefox 3.5+, etc). When a valid JSON string is parsed, the result is a JavaScript object, array or other value. JSON.parse('"bar of foo"') // "bar of foo" (t...

Probably the two most popular free implementations of Common Lisp are Clozure Common Lisp (CCL) and Steel Bank Common Lisp (SBCL). They are both available for a variety of platforms including Linux on x86-64 and Linux on ARM. CCL: http://ccl.clozure.com/download.html SBCL: http://www.sbcl.org/gett...

A BlockingQueue is an interface, which is a queue that blocks when you try to dequeue from it and the queue is empty, or if you try to enqueue items to it and the queue is already full. A thread trying to dequeue from an empty queue is blocked until some other thread inserts an item into the queue. ...

Constraint created as NSLayoutConstraint(item: myView, attribute: NSLayoutAttribute.Leading, relatedBy: NSLayoutRelation.Equal, toItem: view, attribute: NSLayoutAttribute.LeadingMargin, multiplier: 1.0, constant: 20.0) or, from math point of view: view.attribute * multiplier + constant ...

The following function finds the maximal element in an array: int find_max(const int *array, size_t len) { int max = INT_MIN; for (size_t i = 0; i < len; i++) { if (max < array[i]) { max = array[i]; } } return max; } The input size is the...

The following function checks if an array has any duplicates by taking each element, then iterating over the whole array to see if the element is there _Bool contains_duplicates(const int *array, size_t len) { for (int i = 0; i < len - 1; i++) { for (int j = 0; j < len; j++) { ...

Anonymous functions can be used for functional programming. The main problem to solve is that there is no native way for anchoring a recursion, but this can still be implemented in a single line: if_ = @(bool, tf) tf{2-bool}(); This function accepts a boolean value and a cell array of two functi...

Use the package percolate:synced-cron Define a job: SyncedCron.add({ name: 'Find new matches for a saved user filter and send alerts', schedule: function(parser) { // parser is a later.parse object return parser.text('every 10 minutes'); }, job: function() { user.alerts...

Since lots of beginners are confused about cloud hosting.I am writing this guide to walk through setting meteor on aws with ubuntu os. If you already have your instance running feel free to skip this step and go straight to installing meteor on aws. Login into AWS Console.Select EC2. Go to EC2 Dash...

Find files larger than 15MB: find -type f -size +15M Find files less than 12KB: find -type f -size -12k Find files exactly of 12KB size: find -type f -size 12k Or find -type f -size 12288c Or find -type f -size 24b Or find -type f -size 24 General format: find [options] -siz...

UML is not about diagramming. It is about choosing the right words to express some (in most cases technical) context. Diagrams are a means to present the chosen text to humans since a visual perception is generally a good way to convey information. So you will be using graphical elements not in orde...