Tutorial by Examples: cond

The Default keyword is used to execute an action when no other conditions match the input value. Example: switch('Condition') { 'Skip Condition' { 'First Action' } 'Skip This Condition Too' { 'Second Action' } Default { 'Default Action' } } Output: D...

Patterns can be matched based on values independent to the value being matched using if guards: // Let's imagine a simplistic web app with the following pages: enum Page { Login, Logout, About, Admin } // We are authenticated let is_authenticated = true; // But we aren't admins...

The for keyword is also used for conditional loops, traditionally while loops in other programming languages. package main import ( "fmt" ) func main() { i := 0 for i < 3 { // Will repeat if condition is true i++ fmt.Println(i) } } play ...

First download anaconda from the Continuum site. Either via the graphical installer (Windows/OSX) or running a shell script (OSX/Linux). This includes pandas! If you don't want the 150 packages conveniently bundled in anaconda, you can install miniconda. Either via the graphical installer (Window...

prop_evenNumberPlusOneIsOdd :: Integer -> Property prop_evenNumberPlusOneIsOdd x = even x ==> odd (x + 1) If you want to check that a property holds given that a precondition holds, you can use the ==> operator. Note that if it's very unlikely for arbitrary inputs to match the precondit...

Syntax {condition-to-evaluate} ? {statement-executed-on-true} : {statement-executed-on-false} As shown in the syntax, the Conditional Operator (also known as the Ternary Operator1) uses the ? (question mark) and : (colon) characters to enable a conditional expression of two possible outcomes. It c...

To avoid verbose null checking, the ?. operator has been introduced in the language. The old verbose syntax: If myObject IsNot Nothing AndAlso myObject.Value >= 10 Then Can be now replaced by the concise: If myObject?.Value >= 10 Then The ? operator is particularly powerful when you...

The number of seconds from the current date and time for the new date. Use a negative value to specify a date before the current date. For doing this we have a method named dateWithTimerIntervalSinceNow(seconds: NSTimeInterval) -> NSDate (Swift) or + (NSDate*)dateWithTimeIntervalSinceNow:(NSTime...

To get the timestamp in seconds Math.floor((new Date().getTime()) / 1000)

string dateFormat = "MM/dd/yyyy hh:mm:ss.fffffff"; DateTime date1 = new DateTime(2010, 9, 8, 16, 0, 0); Console.WriteLine("Original date: {0} ({1:N0} ticks)\n", date1.ToString(dateFormat), date1.Ticks); DateTime date2 = date1.AddMilliseconds(1); Console....

Due to Node's asynchronous nature, creating or using a directory by first: checking for its existence with fs.stat(), then creating or using it depending of the results of the existence check, can lead to a race condition if the folder is created between the time of the check and the time of ...

The static method Date.now returns the number of milliseconds that have elapsed since 1 January 1970 00:00:00 UTC. To get the number of milliseconds that have elapsed since that time using an instance of a Date object, use its getTime method. // get milliseconds using static method now of Date co...

Preconditions allows methods to provide minimum required values for input parameters Example... void DoWork(string input) { Contract.Requires(!string.IsNullOrEmpty(input)); //do work } Static Analysis Result...

Postconditions ensure that the returned results from a method will match the provided definition. This provides the caller with a definition of the expected result. Postconditions may allowed for simplied implmentations as some possible outcomes can be provided by the static analyizer. Example......

In the condition of the for and while loops, it's also permitted to declare an object. This object will be considered to be in scope until the end of the loop, and will persist through each iteration of the loop: for (int i = 0; i < 5; ++i) { do_something(i); } // i is no longer in scope...

cond do 0 == 1 -> IO.puts "0 = 1" 2 == 1 + 1 -> IO.puts "1 + 1 = 2" 3 == 1 + 2 -> IO.puts "1 + 2 = 3" end # Outputs "1 + 1 = 2" (first condition evaluating to true) cond will raise a CondClauseError if no conditions are true. co...

type Person = { Age : int PassedDriversTest : bool } let someone = { Age = 19; PassedDriversTest = true } match someone.PassedDriversTest with | true when someone.Age >= 16 -> printfn "congrats" | true -> printfn "wait until you are 16" | false -> p...

In oracle, the difference (in days and/or fractions thereof) between two DATEs can be found using subtraction: SELECT DATE '2016-03-23' - DATE '2015-12-25' AS difference FROM DUAL; Outputs the number of days between the two dates: DIFFERENCE ---------- 89 And: SELECT TO_DATE( '201...

6.0 Introduced in C# 6.0, the Null Conditional Operator ?. will immediately return null if the expression on its left-hand side evaluates to null, instead of throwing a NullReferenceException. If its left-hand side evaluates to a non-null value, it is treated just like a normal . operator. Note tha...

Adding a Conditional attribute from System.Diagnostics namespace to a method is a clean way to control which methods are called in your builds and which are not. #define EXAMPLE_A using System.Diagnostics; class Program { static void Main() { ExampleA(); // This method will ...