Tutorial by Examples: d

Wrapping Method Declarations

int someMethod(String aString, List<Integer> aList, Map<String, String> aMap, int anInt, long aLong, Set<Number> aSet, double aDouble) { … } int someMethod(String aString, List&...

Java Language • Oracle Official Code Standard

One variable per declaration (and at most one declaration per line) Square brackets of arrays should be at the type (String[] args) and not on the variable (String args[]). Declare a local variable right before it is first used, and initialize it as close to the declaration as possible.

Java Language • Oracle Official Code Standard

Lambda Expressions

Runnable r = () -> System.out.println("Hello World"); Supplier<String> c = () -> "Hello World"; // Collection::contains is a simple unary method and its behavior is // clear from the context. A method reference is preferred here. appendFilter(goodStrings::cont...

Java Language • Oracle Official Code Standard

Redundant Parentheses

return flag ? "yes" : "no"; String cmp = (flag1 != flag2) ? "not equal" : "equal"; // Don't do this return (flag ? "yes" : "no"); Redundant grouping parentheses (i.e. parentheses that does not affect evaluation) may be used if t...

Java Language • Oracle Official Code Standard

How HTML templates prevent malicious code injection

First, here's what can happen when text/template is used for HTML. Note Harry's FirstName property). package main import ( "fmt" "html/template" "os" ) type Person struct { FirstName string LastName string Street string Cit...

Go • Text + HTML Templating

Basic methods

Methods in Go are just like functions, except they have receiver. Usually receiver is some kind of struct or type. package main import ( "fmt" ) type Employee struct { Name string Age int Rank int } func (empl *Employee) Promote() { empl.Rank++ } ...

Go • Methods

Chaining methods

With methods in golang you can do method "chaining" passing pointer to method and returning pointer to the same struct like this: package main import ( "fmt" ) type Employee struct { Name string Age int Rank int } func (empl *Employee) Promote() *...

Go • Methods

lineWidth (A path styling attribute)

context.lineWidth=lineWidth Sets the width of the line that will stroke the outline of the path <!doctype html> <html> <head> <style> body{ background-color:white; } #canvas{border:1px solid red; } </style> <script> window.onload=(function(){...

html5-canvas • Path (Syntax only)

shadowColor, shadowBlur, shadowOffsetX, shadowOffsetY (path styling attributes)

shadowColor = color // CSS color shadowBlur = width // integer blur width shadowOffsetX = distance // shadow is moved horizontally by this offset shadowOffsetY = distance // shadow is moved vertically by this offset This set of attributes will add a shadow around a path. Bo...

html5-canvas • Path (Syntax only)

createLinearGradient (creates a path styling object)

var gradient = createLinearGradient( startX, startY, endX, endY ) gradient.addColorStop(gradientPercentPosition, CssColor) gradient.addColorStop(gradientPercentPosition, CssColor) [optionally add more color stops to add to the variety of the gradient] Creates a reusable linear gradient (object...

html5-canvas • Path (Syntax only)

createRadialGradient (creates a path styling object)

var gradient = createRadialGradient( centerX1, centerY1, radius1, // this is the "display' circle centerX2, centerY2, radius2 // this is the "light casting" circle ) gradient.addColorStop(gradientPercentPosition, CssColor) gradient.addColorStop(gradientPerce...

html5-canvas • Path (Syntax only)

Defining functions for calling from template

package main import ( "fmt" "net/http" "os" "text/template" ) var requestTemplate string = ` {{range $i, $url := .URLs}} {{ $url }} {{(status_code $url)}} {{ end }}` type Requests struct { URLs []string } func main() {...

Go • Templates

Specify configuration file to load

nginx -c <file name> Start NGINX with an explicit configuration file.

nginx • Nginx Configurations

Logical AND and OR operators

These operators have the usual precedence in C++: AND before OR. // You can drive with a foreign license for up to 60 days bool can_drive = has_domestic_license || has_foreign_license && num_days <= 60; This code is equivalent to the following: // You can drive with a foreign licens...

C++ • operator precedence

std::next_permutation

template< class Iterator > bool next_permutation( Iterator first, Iterator last ); template< class Iterator, class Compare > bool next_permutation( Iterator first, Iterator last, Compare cmpFun ); Effects: Sift the data sequence of the range [first, last) into the next lexicograph...

C++ • Standard Library Algorithms

Using Condition Variables

A condition variable is a primitive used in conjunction with a mutex to orchestrate communication between threads. While it is neither the exclusive or most efficient way to accomplish this, it can be among the simplest to those familiar with the pattern. One waits on a std::condition_variable with...

C++ • Threading

Overloading on constness and volatility

Passing a pointer argument to a T* parameter, if possible, is better than passing it to a const T* parameter. struct Base {}; struct Derived : Base {}; void f(Base* pb); void f(const Base* pb); void f(const Derived* pd); void f(bool b); Base b; f(&b); // f(Base*) is better than f(const...

C++ • Overload resolution

Conversion between pointer and integer

An object pointer (including void*) or function pointer can be converted to an integer type using reinterpret_cast. This will only compile if the destination type is long enough. The result is implementation-defined and typically yields the numeric address of the byte in memory that the pointer poin...

C++ • Explicit type conversions

Portuguese DateTime Localization

Highcharts.setOptions({ lang: { loading: 'Aguarde...', months: ['Janeiro', 'Fevereiro', 'Março', 'Abril', 'Maio', 'Junho', 'Julho', 'Agosto', 'Setembro', 'Outubro', 'Novembro', 'Dezembro'], weekdays: ['Domingo', 'Segunda', 'Terça', 'Quarta', 'Quinta', 'Sex...

highcharts • Localization

Russian DateTime Localization

Highcharts.setOptions({ lang: { loading: 'Загрузка...', months: ['Январь', 'Февраль', 'Март', 'Апрель', 'Май', 'Июнь', 'Июль', 'Август', 'Сентябрь', 'Октябрь', 'Ноябрь', 'Декабрь'], weekdays: ['Воскресенье', 'Понедельник', 'Вторник', 'Среда', 'Четверг', 'П...

highcharts • Localization