Tutorial by Examples: ha

db.posts.find().forEach(function(doc){ if(!doc.foo){ db.posts.update({_id: doc._id}, {$set:{'foo':'bar'}}, false, true); } });

db.posts.find().forEach(function(doc){ if(doc.foo === 'bar'){ db.posts.update({_id: doc._id}, {$set:{'foo':'squee'}}, false, true); } });

What we're doing here is referencing the array index using dot notation db.posts.find({"tags.0": {$exists: true }})

This project is a self-contained example done completely in the Interface Builder. You should be able to work through it in 10 minutes or less. Then you can apply the concepts you learned to your own project. Here I just use UIViews but they can represent whatever view you like (ie, button, label...

CSS div { height: 200px; width: 200px; background: url(http://lorempixel.com/200/200/nature/1); mask-image: linear-gradient(to right, white, transparent); } HTML <div></div> In the above example there is an element with an image as its background. The mask that is a...

There are many cases when one has created an NSDate from only an hour and minute format, i.e: 08:12 The downside for this situation is that your NSDate is almost completely "naked" and what you need to do is to create: day, month, year, second and time zone in order to this object to &quo...

NSAttributedString (and its mutable sibling NSMutableAttributedString) allows you to create strings that are complex in their appearance to the user. A common application is to use this to display a string and adding custom kerning / letter-spacing. This would be achieved as follows (where label ...

CSS div { /* check remarks before usage */ height: 200px; width: 400px; background-image: url(http://lorempixel.com/400/200/nature/4); mask-image: linear-gradient(to top right, transparent 49.5%, white 50.5%), linear-gradient(to top left, transparent 49.5%, white 50.5%), linear-gradient...

$ git reset --hard HEAD^ # discard last commit $ git rebase --interactive HEAD~5 # rebase last 4 commits A suffix ^ to a revision parameter means the first parent of that commit object. ^<n> means the <n>-th parent (i.e. <rev>^ is equivalent to <rev>^1). A...

We can use Channel to copy file content faster. To do so, we can use transferTo() method of FileChannel . import java.io.File; import java.io.FileInputStream; import java.io.FileOutputStream; import java.io.IOException; import java.nio.channels.FileChannel; public class FileCopier { ...

//Creates a Random instance with a seed of 12345. Random random = new Random(12345L); //Gets a ThreadLocalRandom instance ThreadLocalRandom tlr = ThreadLocalRandom.current(); //Set the instance's seed. tlr.setSeed(12345L); Using the same seed to generate random numbers will return the sa...

Bytecode is the set of instructions used by the JVM. To illustrate this let's take this Hello World program. public static void main(String[] args){ System.out.println("Hello World"); } This is what it turns into when compiled into bytecode. public static main([Ljava/lang/String...

Firstly the classes from the jar need to be loaded. We'll use three methods for this process: loadClasses(File) readJar(JarFile, JarEntry, Map) getNode(byte[]) Map<String, ClassNode> loadClasses(File jarFile) throws IOException { Map<String, ClassNode> classes = new HashMap&...

To write data to a file using Channel we need to have the following steps: First, we need to get an object of FileOutputStream Acquire FileChannel calling the getChannel() method from the FileOutputStream Create a ByteBuffer and then fill it with data Then we have to call the flip() method of ...

The tr method returns a copy of a string where the characters of the first argument are replaced by the characters of the second argument. "string".tr('r', 'l') # => "stling" To replace only the first occurrence of a pattern with with another expression use the sub method ...

One Button Swift class ViewController: UIViewController { @IBAction func showAlertButtonTapped(sender: UIButton) { // create the alert let alert = UIAlertController(title: "My Title", message: "This is my message.", preferredStyle: UIAlertCo...

Below code showcases multiple Producer/Consumer program. Both Producer and Consumer threads share same global queue. import java.util.concurrent.*; import java.util.Random; public class ProducerConsumerWithES { public static void main(String args[]) { BlockingQueue<Integer> ...

You can launch an application in several ways, depending on how you create you app. If your app is divided in two files ui.R and server.R or if all of your app is in one file. 1. Two files app Your two files ui.R and server.Rhave to be in the same folder. You could then launch your app by running ...

xml_import_example.info.yml type: module name: XML import example package: Examples description: "This module helps understanding the Batch API and Queue API with an XML import example" core: 8.x xml_import_example.permissions.yml import content from xml: title: 'Import content...

ExampleScript script = GameObject.FindObjectOfType<ExampleScript>(); GameObject go = script.gameObject; FindObjectOfType() returns null if none is found. ProsConsStrongly typedPerformance degrades along the number of gameobjects needed to evaluatePossible to search both single objects...