Tutorial by Examples: ce

Within a catch block the throw keyword can be used on its own, without specifying an exception value, to rethrow the exception which was just caught. Rethrowing an exception allows the original exception to continue up the exception handling chain, preserving its call stack or associated data: try...

A Sub is a procedure that performs a specific task but does not return a specific value. Sub ProcedureName ([argument_list]) [statements] End Sub If no access modifier is specified, a procedure is Public by default. A Function is a procedure that is given data and returns a value, ideally...

Slices are the typical way go programmers store lists of data. To declare a slice variable use the []Type syntax. var a []int To declare and initialize a slice variable in one line use the []Type{values} syntax. var a []int = []int{3, 1, 4, 1, 5, 9} Another way to initialize a slice is with...

Define your class that will represent your custom error. public class ErrorDto { public int Code { get; set; } public string Message { get; set; } // other fields public override string ToString() { return JsonConvert.SerializeObject(this); } } Then put nex...

angular.module("app") .service("counterService", function(){ var service = { number: 0 }; return service; });

angular.module("app") // Custom services are injected just like Angular's built-in services .controller("step1Controller", ['counterService', '$scope', function(counterService, $scope) { counterService.number++; // bind to...

An unnamed namespace can be used to ensure names have internal linkage (can only be referred to by the current translation unit). Such a namespace is defined in the same way as any other namespace, but without the name: namespace { int foo = 42; } foo is only visible in the translation uni...

Private inheritance is useful when it is required to restrict the public interface of the class: class A { public: int move(); int turn(); }; class B : private A { public: using A::turn; }; B b; b.move(); // compile error b.turn(); // OK This approach efficiently pr...

getPreferences(int) returns the preferences saved by Activity's class name as described in the docs : Retrieve a SharedPreferences object for accessing preferences that are private to this activity. This simply calls the underlying getSharedPreferences(String, int) method by passing in this acti...

YourAsyncTask task = new YourAsyncTask(); task.execute(); task.cancel(); This doesn't stop your task if it was in progress, it just sets the cancelled flag which can be checked by checking the return value of isCancelled() (assuming your code is currently running) by doing this: class YourAsyn...

To spawn a new process in which you need unbuffered output (e.g. long-running processes which might print output over a period of time rather than printing and exiting immediately), use child_process.spawn(). This method spawns a new process using a given command and an array of arguments. The retu...

Look at the contents of /etc/redhat-release cat /etc/redhat-release Here is the output from a Fedora 24 machine: Fedora release 24 (Twenty Four) As mentioned in the debian-based response, you can also use the lsb_release -a command, which outputs this from a Fedora 24 machine: LSB Version: ...

You have to keep the operator precedence in mind when using await keyword. Imagine that we have an asynchronous function which calls another asynchronous function, getUnicorn() which returns a Promise that resolves to an instance of class Unicorn. Now we want to get the size of the unicorn using th...

Interaction with the history # List all previous commands history # Clear the history, useful if you entered a password by accident history -c Event designators # Expands to line n of bash history !n # Expands to last command !! # Expands to last command starting with "text&qu...

The second value in the curly braces dictates the length of the replacement string. By adjusting the second value to be positive or negative, the alignment of the string can be changed. string.Format("LEFT: string: ->{0,-5}<- int: ->{1,-5}<-", "abc", 123); string....

The splice()method can be used to remove elements from an array. In this example, we remove the first 3 from the array. var values = [1, 2, 3, 4, 5, 3]; var i = values.indexOf(3); if (i >= 0) { values.splice(i, 1); } // [1, 2, 4, 5, 3] The splice() method can also be used to add elemen...

function foo() { console.trace('My log statement'); } foo(); Will display this in the console: My log statement VM696:1 foo @ VM696:1 (anonymous function) @ (program):1 Note: Where available it's also useful to know that the same stack trace is accessible a...

UDP is a connectionless protocol. This means that peers sending messages do not require establishing a connection before sending messages. socket.recvfromthus returns a tuple (msg [the message the socket received], addr [the address of the sender]) A UDP server using solely the socket module: from...

The following will list up to ten of the most recently modified files in the current directory, using a long listing format (-l) and sorted by time (-t). ls -lt | head

IMPORTANT: This delegate method is only called in the foreground. Swift func application(application: UIApplication, didReceiveLocalNotification notification: UILocalNotification) { } Objective-C - (void)application:(UIApplication *)application didReceiveLocalNotification:(UILocalNotifi...