Tutorial by Examples: u

#include <stdio.h> #include <stdlib.h> #include <string.h> int main(int argc, char **argv) { /* Exit if no second argument is found. */ if (argc != 2) { puts("Argument missing."); return EXIT_FAILURE; } size_t len = str...

println! (and its sibling, print!) provides a convenient mechanism for producing and printing text that contains dynamic data, similar to the printf family of functions found in many other languages. Its first argument is a format string, which dictates how the other arguments should be printed as t...

A function can return one or more values to the caller: func AddAndMultiply(a, b int) (int, int) { return a+b, a*b } The second return value can also be the error var : import errors func Divide(dividend, divisor int) (int, error) { if divisor == 0 { return 0, errors.New(...

Return values can be assigned to a local variable. An empty return statement can then be used to return their current values. This is known as "naked" return. Naked return statements should be used only in short functions as they harm readability in longer functions: func Inverse(v float3...

Struct fields whose names begin with an uppercase letter are exported. All other names are unexported. type Account struct { UserID int // exported accessToken string // unexported } Unexported fields can only be accessed by code within the same package. As such, if you are ev...

Any function can be invoked as a goroutine by prefixing its invocation with the keyword go: func DoMultiply(x,y int) { // Simulate some hard work time.Sleep(time.Second * 1) fmt.Printf("Result: %d\n", x * y) } go DoMultiply(1,2) // first execution, non-blocking go DoMu...

single channel, single goroutine, one write, one read. package main import "fmt" import "time" func main() { // create new channel of type string ch := make(chan string) // start new anonymous goroutine go func() { time.Sleep(time.Second) ...

PorterDuff.Mode is used to create a PorterDuffColorFilter. A color filter modifies the color of each pixel of a visual resource. ColorFilter filter = new PorterDuffColorFilter(Color.BLUE, PorterDuff.Mode.SRC_IN); The above filter will tint the non-transparent pixels to blue color. The color fil...

An Xfermode (think "transfer" mode) works as a transfer step in drawing pipeline. When an Xfermode is applied to a Paint, the pixels drawn with the paint are combined with underlying pixels (already drawn) as per the mode: paint.setColor(Color.BLUE); paint.setXfermode(new PorterDuffXferm...

In info.plist set View controller-based status bar appearance to YES In view controllers not contained by UINavigationController implement this method. In Objective-C: - (UIStatusBarStyle)preferredStatusBarStyle { return UIStatusBarStyleLightContent; } In Swift: override func pre...

Column aliases are used mainly to shorten code and make column names more readable. Code becomes shorter as long table names and unnecessary identification of columns (e.g., there may be 2 IDs in the table, but only one is used in the statement) can be avoided. Along with table aliases this allows ...

A simple literal function, printing Hello! to stdout: package main import "fmt" func main() { func(){ fmt.Println("Hello!") }() } play it on playground A literal function, printing the str argument to stdout: package main import "fmt&quot...

A variadic function can be called with any number of trailing arguments. Those elements are stored in a slice. package main import "fmt" func variadic(strs ...string) { // strs is a slice of string for i, str := range strs { fmt.Printf("%d: %s\n", i, ...

Warning: be sure you have at least 15 GB of free disk space. Compilation in Ubuntu >=13.04 Option A) Use Git Use git if you want to stay in sync with the latest Ubuntu kernel source. Detailed instructions can be found in the Kernel Git Guide. The git repository does not include necessary ...

Strict mode can also be applied to single functions by prepending the "use strict"; statement at the beginning of the function declaration. function strict() { "use strict"; // strict mode now applies to the rest of this function var innerFunction = function () { ...

try { StyledDocument doc = new DefaultStyledDocument(); doc.insertString(0, "This is the beginning text", null); doc.insertString(doc.getLength(), "\nInserting new line at end of doc", null); MutableAttributeSet attrs = new SimpleAttributeSet(); StyleCons...

try { JTextPane pane = new JTextPane(); StyledDocument doc = new DefaultStyledDocument(); doc.insertString(0, "Some text", null); pane.setDocument(doc); //Technically takes any subclass of Document } catch (BadLocationException ex) { //hand...

StyledDocuments generally do not implement clone, and so have to copy them in a different way if that is necessary. try { //Initialization DefaultStyledDocument sourceDoc = new DefaultStyledDocument(); DefaultStyledDocument destDoc = new DefaultStyledDocument(); ...

There are several PHP functions that accept user-defined callback functions as a parameter, such as: call_user_func(), usort() and array_map(). Depending on where the user-defined callback function was defined there are different ways to pass them: Procedural style: function square($number) { ...

// zoo.php class Animal { public function eats($food) { echo "Yum, $food!"; } } $animal = new Animal(); $animal->eats('meat'); PHP knows what Animal is before executing new Animal, because PHP reads source files top-to-bottom. But what if we wanted to create ...