Tutorial by Examples: p

UIBezierPath using to create a circular path ShapeLayer CAShapeLayer *circleLayer = [CAShapeLayer layer]; [circleLayer setPath:[[UIBezierPath bezierPathWithOvalInRect: CGRectMake(50, 50, 100, 100)] CGPath]]; circleLayer.lineWidth = 2.0; [circleLayer setStrokeColor:[[UIColor redColor] CGColor]];...

When checking if a string is zero-length, it is better practice, and more efficient, to inspect the length of the string rather than comparing the string to an empty string. Const myString As String = vbNullString 'Prefer this method when checking if myString is a zero-length string If Len(mySt...

It may be a good idea to encapsulate the HTTP handling logic in its own class. The following class exposes a method for getting Posts. It calls the http.get() method and calls .map on the returned Observable to convert the Response object to a Post object. import {Injectable} from "@angular/co...

One common scenario is to wait for a number of requests to finish before continuing. This can be accomplished using the forkJoin method. In the following example, forkJoin is used to call two methods that return Observables. The callback specified in the .subscribe method will be called when both O...

Any time SQL executed through an ADO connection needs to contain user input, it is considered best practice to parameterize it in order to minimize the chance of SQL injection. This method is also more readable than long concatenations and facilitates more robust and maintainable code (i.e. by using...

The following example utilizes the tm text mining package to scrape and mine text data from the web to build word clouds with symbolic shading and ordering. require(RWeka) require(tau) require(tm) require(tm.plugin.webmining) require(wordcloud) # Scrape Google Finance -----------------------...

Const string1 As String = "foo" Const string2 As String = "bar" Const string3 As String = "fizz" Dim concatenatedString As String 'Concatenate two strings concatenatedString = string1 & string2 'concatenatedString = "foobar" 'Concatenate three s...

Dim lineOfHyphens As String 'Assign a string with 80 repeated hyphens lineOfHyphens = String$(80, "-")

Dim stringOfSpaces As String 'Assign a string with 255 repeated spaces using Space$ stringOfSpaces = Space$(255) 'Assign a string with 255 repeated spaces using String$ stringOfSpaces = String$(255, " ")

The purpose of this example is to show how we can realize the Strategy pattern using Java 8 functional interfaces. We will start with a simple use case codes in classic Java, and then recode it in the Java 8 way. The example problem we using is a family of algorithms (strategies) that describe dif...

from module.submodule import function This imports function from module.submodule.

from datetime import timedelta from django.utils import timezone from psycopg2.extras import DateTimeTZRange # To create a "period" object we will use psycopg2's DateTimeTZRange # which takes the two datetime bounds as arguments period_start = timezone.now() period_end = period_s...

Use assert_raise to test if an exception was raised. assert_raise takes in an Exception and a function to be executed. test "invalid block size" do assert_raise(MerkleTree.ArgumentError, (fn() -> MerkleTree.new ["a", "b", "c"] end)) end Wrap a...

Hierarchy - LinearLayout(horizontal) - ImageView - LinearLayout(vertical) - TextView - TextView Code LinearLayout rootView = new LinearLayout(context); rootView.setLayoutParams(new LinearLayout.LayoutParams(LayoutParams.MATCH_PARENT, LayoutParams.WRAP_CONTENT)); rootView.s...

Simple item insertion can be done with Array.prototype.splice method: arr.splice(index, 0, item); More advanced variant with multiple arguments and chaining support: /* Syntax: array.insert(index, value1, value2, ..., valueN) */ Array.prototype.insert = function(index) { this.splice.a...

With the appropriate storage backend running a new titan graph can be initialised via: graph = TitanFactory.open("config.properties"); Wehere config.properties defines several configurations relevant to the storage backend. Titan provides some sample configs in its downloadable package...

First, install socket.io module in node.js application. npm install socket.io --save Basic HTTP Setup The following example attaches socket.io to a plain node.js HTTP server listening on port 3000. var server = require('http').createServer(); var io = require('socket.io')(server); io.on(...

#!/usr/bin/env perl use strict; use warnings 'all'; use XML::Twig; my $twig = XML::Twig->parse( \*DATA ); #we can use the 'root' method to find the root of the XML. my $root = $twig->root; #first_child finds the first child element matching a value. my $title = $root->firs...

Pseudo-elements are often used to change the look of lists (mostly for unordered lists, ul). The first step is to remove the default list bullets: ul { list-style-type: none; } Then you add the custom styling. In this example, we will create gradient boxes for bullets. li:before { conte...

The default gnuplot command plot (also only p) plot dataset with columns, of the form of the data_set.dat file below. # Prototype of a gnuplot data set # data_set.dat # X - X^2 - 2*X - Random 0 0 0 5 1 1 2 15 1.4142 2 2.8284 1 2 ...