Tutorial by Examples: v

No Java variable represents an object. String foo; // NOT AN OBJECT Neither does any Java array contain objects. String bar[] = new String[100]; // No member is an object. If you mistakenly think of variables as objects, the actual behavior of the Java language will surprise you. For...

It's possible to make a simple lazily-evaluated list using mutable types and closures. A lazily-evaluated list is a list whose elements are not evaluated when it's constructed, but rather when it is accessed. Benefits of lazily evaluated lists include the possibility of being infinite. import Base:...

to_upper(): #include <iostream> #include <string> #include <boost/algorithm/string.hpp> using namespace std; int main() { // String to convert characters to uppercase string str = "ThIS iS SUpPoSEd tO Be UpPeR CAsE."; // Convert characters i...

The typical Visitor example in Java would be: interface ShapeVisitor { void visit(Circle c); void visit(Rectangle r); } interface Shape { void accept(ShapeVisitor sv); } class Circle implements Shape { private Point center; private double radius; public Circl...

Objective-C NSMutableAttributedString *str = [[NSMutableAttributedString alloc] initWithString:@"Hello. That is a test attributed string."]; [str addAttribute:NSBackgroundColorAttributeName value:[UIColor yellowColor] range:NSMakeRange(3,5)]; [str addAttribute:NSForegroundColorAttrib...

IF you are using simple categories, with each physics body belonging to only one category, then this alternative form of didBeginContact may be more readable: func didBeginContact(contact: SKPhysicsContact) { let contactMask = contact.bodyA.categoryBitMask | contact.bodyB.categoryBitMask ...

Here is a simple Sprite-Kit GameScene.swift. Create a new, empty SpriteKit project and replace the GameScene.swift with this. Then build and run. Click on any of the objects on screen to give make them move. Check the logs and the comments to see which ones collide and which ones make contact. // ...

If the tables use InnoDB, MySQL automatically uses row level locking so that multiple transactions can use same table simultaneously for read and write, without making each other wait. If two transactions trying to modify the same row and both uses row level locking, one of the transactions waits f...

Fetching or loading data can be primarily classified into two types: eager and lazy. In order to use Hibernate make sure you add the latest version of it to the dependencies section of your pom.xml file: <dependency> <groupId>org.hibernate</groupId> <artifactId>hi...

;;Recursively print the elements of a list (defun print-list (elements) (cond ((null elements) '()) ;; Base case: There are no elements that have yet to be printed. Don't do anything and return a null list. (t ;; Recursive case ;; Print the next elem...

Most examples of a function returning a value involve providing a pointer as one of the arguments to allow the function to modify the value pointed to, similar to the following. The actual return value of the function is usually some type such as an int to indicate the status of the result, whether ...

Debugging by raising exceptions is far easier than squinting through print log statements, and for most bugs, its generally much faster than opening up an irb debugger like pry or byebug. Those tools should not be your first step. Debugging Ruby/Rails Quickly: 1. Fast Method: Raise an Exceptio...

UIDevice *deviceInfo = [UIDevice currentDevice]; NSLog(@"Device Name %@", deviceInfo.name); //Ex: myIphone6s NSLog(@"System Name %@", deviceInfo.systemName); //Device Name iPhone OS NSLog(@"System Version %@", deviceInfo.systemVersion); //System Version 9.3...

UIDevice *deviceInfo = [UIDevice currentDevice]; int d = deviceInfo.orientation; deviceInfo.orientation returns an UIDeviceOrientation value which is shown as below: UIDeviceOrientationUnknown 0 UIDeviceOrientationPortrait 1 UIDeviceOrientationPortraitUpsideDown 2 UIDeviceOrientationLandscap...

//Get permission for Battery Monitoring [[UIDevice currentDevice] setBatteryMonitoringEnabled:YES]; UIDevice *myDevice = [UIDevice currentDevice]; [myDevice setBatteryMonitoringEnabled:YES]; double batLeft = (float)[myDevice batteryLevel] * 100; NSLog(@"%.f",batLeft); int d = myD...

String to immutable ubyte[] string s = "unogatto"; immutable(ubyte[]) ustr = cast(immutable(ubyte)[])s; assert(typeof(ustr).stringof == "immutable(ubyte[])"); assert(ustr.length == 8); assert(ustr[0] == 0x75); //u assert(ustr[1] == 0x6e); //n assert(ustr[2] == 0x6f); //o...

01 a PIC 9. 01 b PIC 99. 01 c PIC 999. 01 s PIC X(4). 01 record-group. 05 field-a PIC 9. 05 field-b PIC 99. 05 field-c PIC 999. 01 display-record. 05 field-a PIC Z. 05 field-b PIC ZZ. 05 field-c PIC $Z9. *> numeric fields are moved left to right *> a set to...

Any method in Rails model can return boolean value. simple method- ##this method return ActiveRecord::Relation def check_if_user_profile_is_complete User.includes( :profile_pictures,:address,:contact_detail).where("user.id = ?",self) end Again simple method returning bool...

Usually when generating random numbers it is useful to generate integers within a range, or a p value between 0.0 and 1.0. Whilst modulus operation can be used to reduce the seed to a low integer this uses the low bits, which often go through a short cycle, resulting in a slight skewing of distribut...

Overloading the addition operator (+) requires implement the std::ops::Add trait. From the documentation, the full definition of the trait is: pub trait Add<RHS = Self> { type Output; fn add(self, rhs: RHS) -> Self::Output; } How does it work? the trait is implemented for...