Tutorial by Examples: co

class Message DEFAULT_MESSAGE = "Hello, world" def speak(message = nil) if message puts message else puts DEFAULT_MESSAGE end end end The constant DEFAULT_MESSAGE can be changed with the following code: Message::DEFAULT_MESSAGE = "Hullo, wo...

def results = [] (1..4).each{ def what = (it%2) ? 'odd' : 'even' results << what } assert results == ['odd', 'even', 'odd', 'even'] Here, the if-condition (in (parentheses)) is slightly more complex than just testing for existence/Groovy-Truth.

In Emacs M-x slime will start slime with the default (first) Common Lisp implementation. If there are multiple implementations provided (via variable slime-lisp-implementations), other implementations can be accessed via M-- M-x slime, which will offer the choice of available implementations in mini...

C++17 namespace a { namespace b { template<class T> struct qualifies : std::false_type {}; } } namespace other { struct bob {}; } namespace a::b { template<> struct qualifies<::other::bob> : std::true_type {}; } You can enter both the a and b n...

Example: Invoke different constructors by passing relevant parameters import java.lang.reflect.*; class NewInstanceWithReflection{ public NewInstanceWithReflection(){ System.out.println("Default constructor"); } public NewInstanceWithReflection( String a){ ...

Compare two Strings ignoring case: "School".equalsIgnoreCase("school"); // true Don't use text1.toLowerCase().equals(text2.toLowerCase()); Languages have different rules for converting upper and lower case. A 'I' would be converted to 'i' in English. But in Turkish a 'I' ...

public class InsertIntoConcurrentHashMap { public static void main(String[] args) { ConcurrentHashMap<Integer, SomeObject> concurrentHashMap = new ConcurrentHashMap<>(); SomeObject value = new SomeObject(); Integer key = 1; SomeObject ...

import java.util.ArrayList; import java.util.List; import static java.lang.System.out; public class PolymorphismDemo { public static void main(String[] args) { List<FlyingMachine> machines = new ArrayList<FlyingMachine>(); machines.add(new FlyingMachine())...

This function copies data between two streams - void copy(InputStream in, OutputStream out) throws IOException { byte[] buffer = new byte[8192]; while ((bytesRead = in.read(buffer)) > 0) { out.write(buffer, 0, bytesRead); } } Example - // reading from System.in and ...

Let's say you have this line of code: printf("Hello, world!\n"); Now say you want to change the text to "Program exiting." CommandBufferMnemonicci"printf("¦");change in the ".Program exiting.\n<esc>printf("Program exiting.\n");

Using else we can perform some task when the condition is not satisfied. But what if we want to check a second condition in case that the first one was false. We can do it this way: a = 9; if mod(a,2)==0 % MOD - modulo operation, return the remainder after division of 'a' by 2 disp('a is ev...

When we use a condition within another condition we say the conditions are "nested". One special case of nested conditions is given by the elseif option, but there are numerous other ways to use nested conditons. Let's examine the following code: a = 2; if mod(a,2)==0 % MOD - modulo o...

To check if a required gem is installed, from within your code, you can use the following (using nokogiri as an example): begin found_gem = Gem::Specification.find_by_name('nokogiri') require 'nokogiri' .... <the rest of your code> rescue Gem::LoadError end However, this can ...

This can be easily accomplished by calling Enumerable#to_a on a Range object: (1..10).to_a #=> [1, 2, 3, 4, 5, 6, 7, 8, 9, 10] (a..b) means that it will include all numbers between a and b. To exclude the last number, use a...b a_range = 1...5 a_range.to_a #=> [1, 2, 3, 4] or...

Quite often it's necessary to send/upload a file to a remote server, for example, an image, video, audio or a backup of the application database to a remote private server. Assuming the server is expecting a POST request with the content, here's a simple example of how to complete this task in Andro...

You use the condition attribute to specify the condition to use. <cfset myVar=false> <cfloop condition="myVar eq false"> <cfoutput> myVar = <b>#myVar#</b> (still in loop)<br /> </cfoutput> <cfif RandRange(1,10) eq 10> ...

You can loop over a Structure or COM collection. <cfset myBooks = StructNew()> <cfset myVariable = StructInsert(myBooks,"ColdFusion","ColdFusion MX Bible")> <cfset myVariable = StructInsert(myBooks,"HTML","HTML Visual QuickStart")> <cf...

Creating Gradient UIImage with colors in CGRect Swift: extension UIImage { static func gradientImageWithBounds(bounds: CGRect, colors: [CGColor]) -> UIImage { let gradientLayer = CAGradientLayer() gradientLayer.frame = bounds gradientLayer.colors = colors ...

SQL Server 2012 Returns a string that is the result of two or more strings joined together. CONCAT accepts two or more arguments. SELECT CONCAT('This', ' is', ' my', ' string') -- returns 'This is my string' Note: Unlike concatenating strings using the string concatenation operator (+), when ...

Returns the integer value representing the Unicode value of the first character of the input expression. Parameters: Unicode character expression. Any valid nchar or nvarchar expression. SELECT UNICODE(N'Ɛ') -- Returns 400 DECLARE @Unicode nvarchar(11) = N'Ɛ is a char' SELECT UNICODE(@Uni...