Tutorial by Examples: io

def str = 'old' def interpolated = "I am the ${str} value" assert interpolated == 'I am the old value' str = 'new' assert interpolated == 'I am the old value'

We can have lazy interpolation in Strings. This is different than normal interpolation as the GString can potentially have different values, depending on the closure, whenever it is converted into a String. def str = 'old' def interpolated = "I am the ${ -> str} value" assert interpo...

def str = 'dsl' def interpolated = "Groovy ${str.length() + 1} easy ${str.toUpperCase()}" assert interpolated == 'Groovy 4 easy DSL' str = 'Domain specific language' assert interpolated == 'Groovy 4 easy DSL'

The navigation bar (at the bottom of the screen) can be transparent. Here is the way to achieve it. <style name="AppTheme" parent="Theme.AppCompat"> <item name="android:windowTranslucentNavigation">true</item> </style> The Status Bar (t...

5.0 This attribute is used to change the navigation bar (one, that contain Back, Home Recent button). Usually it is black, however it's color can be changed. <style name="AppTheme" parent="Theme.AppCompat"> <item name="android:navigationBarColor">@col...

Given two types T and U, &T will coerce (implicitly convert) to &U if and only if T implements Deref<Target=U> This allows us to do things like this: fn foo(a: &[i32]) { // code } fn bar(s: &str) { // code } let v = vec![1, 2, 3]; foo(&v); // &Vec&l...

As well as being able to create an array by filtering out nil from the transformed elements of a sequence, there is also a version of flatMap(_:) that expects the transformation closure to return a sequence S. extension SequenceType { public func flatMap<S : SequenceType>(transform: (Sel...

Dart functions may also be declared anonymously or nested. For example, to create a nested function, just open a new function block within an existing function block void outerFunction() { bool innerFunction() { /// Does stuff } } The function innerFunction may now be us...

ALTER TABLE foo ENGINE=InnoDB; This converts the table, but does not take care of any differences between the engines. Most differences will not matter, especially for small tables. But for busier tables, other considerations should be considered. Conversion considerations

<svg xmlns="http://www.w3.org/2000/svg" xmlns:xlink="http://www.w3.org/1999/xlink"> <circle r="30" cx="100" cy="100" fill="rgb(255, 0, 0)" stroke="rgb(0, 255, 0)" /> <rect x="200" y="200" w...

PrimitiveBoxed TypeMemory Size of primitive / boxedbooleanBoolean1 byte / 16 bytesbyteByte1 byte / 16 bytesshortShort2 bytes / 16 bytescharChar2 bytes / 16 bytesintInteger4 bytes / 16 byteslongLong8 bytes / 16 bytesfloatFloat4 bytes / 16 bytesdoubleDouble8 bytes / 16 bytes Boxed objects always requ...

UPDATE person SET state = 'NY' WHERE city = 'New York';

Variables declared inside a function only exist (unless passed) inside that function. x <- 1 foo <- function(x) { y <- 3 z <- x + y return(z) } y Error: object 'y' not found Variables passed into a function and then reassigned are overwritten, but only insi...

Functions called within a function (ie subfunctions) must be defined within that function to access any variables defined in the local environment without being passed. This fails: bar <- function() { z <- x + y return(z) } foo <- function() { y <- 3 z <-...

The on.exit() function is handy for variable clean up if global variables must be assigned. Some parameters, especially those for graphics, can only be set globally. This small function is common when creating more specialized plots. new_plot <- function(...) { old_pars <- par(m...

Installing the haystack package pip install django-haystack Configuration Add haystack to your project's INSTALLED_APPS inside of your settings.py file: # settings.py INSTALLED_APPS = [ 'django.contrib.admin', 'django.contrib.auth', 'django.contrib.contenttypes', # Put...

Create custom class for calling multipart/form-data HttpURLConnection request MultipartUtility.java public class MultipartUtility { private final String boundary; private static final String LINE_FEED = "\r\n"; private HttpURLConnection httpConn; priva...

The option -v followed by an assignment of the form variable=value can be used to pass parameters to an awk program. This is illustrated by the punishment program below, whose job is to write count times the sentence “I shall not talk in class.” on standard output. The following example uses the v...

ng-model-options allows to change the default behavior of ng-model, this directive allows to register events that will fire when the ng-model is updated and to attach a debounce effect. This directive accepts an expression that will evaluate to a definition object or a reference to a scope value. ...

// Returns the nth number in the Fibonacci sequence function fibonacci(n) { if (n === 1 || n === 0) { return 1; } else { return fibonacci(n - 1) + fibonacci(n - 2); } }