Tutorial by Examples: n

// The allocation functions have implementation-defined behavior when the requested size // of the allocation is zero. void *p = malloc(0);

UISplitViewController must be the rootViewController of your application. AppDelegate.m - (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions { // Override point for customization after application launch. self.window = [[UIWindow alloc] i...

It is illegal to access a reference to an object that has gone out of scope or been otherwise destroyed. Such a reference is said to be dangling since it no longer refers to a valid object. #include <iostream> int& getX() { int x = 42; return x; } int main() { int& r...

itertools.permutations returns a generator with successive r-length permutations of elements in the iterable. a = [1,2,3] list(itertools.permutations(a)) # [(1, 2, 3), (1, 3, 2), (2, 1, 3), (2, 3, 1), (3, 1, 2), (3, 2, 1)] list(itertools.permutations(a, 2)) [(1, 2), (1, 3), (2, 1), (2, 3), (3...

Let's test our basic knowledge of tkinter by creating the classic "Hello, World!" program. First, we must import tkinter, this will vary based on version (see remarks section about "Differences between Python 2 and 3") In Python 3 the module tkinter has a lowercase t: import t...

import tkinter as tk class HelloWorld(tk.Frame): def __init__(self, parent): super(HelloWorld, self).__init__(parent) self.label = tk.Label(self, text="Hello, World!") self.label.pack(padx=20, pady=20) if __name__ == "__main__": ...

Pair allows us to treat two objects as one object. Pairs can be easily constructed with the help of template function std::make_pair. Alternative way is to create pair and assign its elements (first and second) later. #include <iostream> #include <utility> int main() { std::p...

In pass by value of parameter passing to a method, actual parameter value is copied to formal parameter value. So actual parameter value will not change after returning from called function. @interface SwapClass : NSObject -(void) swap:(NSInteger)num1 andNum2:(NSInteger)num2; @end @impleme...

In pass by reference of parameter passing to a method, address of actual parameter is passed to formal parameter. So actual parameter value will be changed after returning from called function. @interface SwapClass : NSObject -(void) swap:(int)num1 andNum2:(int)num2; @end @implementation S...

The example Checking a string for unwanted characters, describes how to test and reject strings that don't meet certain criteria. Obviously, rejecting input outright is not always possible, and sometimes you just have to make do with what you receive. In these cases, a cautious developer will attemp...

Have a look in your php.ini configuration file and enable Xdebug, add the following statement: [Xdebug] zend_extension=<full_path_to_xdebug_extension> xdebug.remote_enable=1 xdebug.remote_host=<the host where PhpStorm is running (e.g. localhost)> xdebug.remote_port=<the port to w...

Launch debug by clicking on the "beetle" icon: Debug window is now waiting instructions for next step: You can go to the next step by clicking F9 in the debug window or by clicking on the green arrow:

While Python has an assert statement, the Python unit testing framework has better assertions specialized for tests: they are more informative on failures, and do not depend on the execution's debug mode. Perhaps the simplest assertion is assertTrue, which can be used like this: import unittest ...

GNU Emacs uses a special format for documentation: info. The Common Lisp standard has been converted to the Texinfo format, which can be used to create documentation browsable with the info reader in GNU Emacs. See here: dpans2texi.el converts the TeX sources of the draft ANSI Common Lisp standard...

While being better in many regards, the new connection syntax in Qt5 has one big weakness: Connecting overloaded signals and slots. In order to let the compiler resolve the overloads we need to use static_casts to member function pointers, or (starting in Qt 5.7) qOverload and friends: #include &lt...

<svg width="800px" height="600px" > <defs> <filter id="posterize" color-interpolation-filters="sRGB"> <feComponentTransfer> <feFuncR type="discrete" tableValues="0 0.25 0.75 1.0"/> ...

The axis offsets for drawing the marker that are specified by refX and refY are applied before the rotation specified by the orient parameter. Below you can see the effects of various combinations of orient and refX, refY to illustrate this. <svg width="800px" height="600px"&...

The default for drawing markers is to use the stroke width of the calling element, but you can explicitly specify that markers be drawn using the unit system for the element the marker is being applied to by specifying markerUnits="userSpaceOnUse". Markers are drawn into a 3x3 markerUnits ...

Elements can specify start, mid and end markers separately. Below are examples of start, mid and end markers for all elements that can be marked. Please note that Chrome does not currently (July 2016) calculate auto orientation correctly for start and end markers for polygons (bug# 633012), and also...

PendingIntent pendingIntent = PendingIntent.getActivity(context, uniqueIntentId, intent, PendingIntent.FLAG_CANCEL_CURRENT); final RemoteViews remoteViews = new RemoteViews(context.getPackageName(), R.layout.remote_view_notification); remoteViews.setImageViewResource(R.id.remote...