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db.posts.find().forEach(function(doc){ if(doc.oldfield){ // the false, true at the end refers to $upsert, and $multi, respectively db.accounts.update({_id: doc._id}, {$unset: {'oldfield': "" }}, false, true); } });

db.posts.find().forEach(function(doc){ db.accounts.update({_id: doc._id}, {$set: {'_id': doc._id.str }}, false, true); });

var newvalue = ""; db.posts.find().forEach(function(doc){ if(doc.foo){ newvalue = '"' + doc.foo + '"'; db.accounts.update({_id: doc._id}, {$set: {'doc.foo': newvalue}}); } });

var newvalue = null; db.posts.find().forEach(function(doc){ if(doc.foo){ newvalue = '"' + doc.foo + '"'; db.accounts.update({_id: doc._id}, {$set: {'doc.foo': newvalue}}); } });

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...

These functions are used to check Mouse Button Clicks. Input.GetMouseButton(int button); Input.GetMouseButtonDown(int button); Input.GetMouseButtonUp(int button); They all take the-same parameter. 0 = Left Mouse Click. 1 = Right Mouse Click. 2 = Middle Mouse Click. GetMouseButton i...

Backbone.js is made up of four separate components: Collections, Models, Routers, and Views. Each of these serve different purposes: Model - represents a single data object, but adds additional functionalities not provided by native JavaScript objects, such as an event system and a more conveni...

Use $state.transitionTo to go form one state to another. This is a low level method to transition and $state.go is the recommended way for most common use cases as it uses this method internally. $state.transitionTo(toState [, toParams] [, options]) toState - the state to transition to toPara...

Recursion can be categorized as either Head Recursion or Tail Recursion, depending on where the recursive method call is placed. In head recursion, the recursive call, when it happens, comes before other processing in the function (think of it happening at the top, or head, of the function). In ta...

AndroidManifest.xml: <activity android:name="com.example.MainActivity" > <intent-filter> <action android:name="android.intent.action.VIEW" /> <category android:name="android.intent.category.DEFAULT" /> <c...

This example illustrates how to configure Jersey so that you can begin using it as a JAX-RS implementation framework for your RESTful API. Assuming that you have already installed Apache Maven, follow these steps to set up Jersey: Create maven web project structure, in terminal (windows) execute...

For programs with a single source file, using gcc is simple. /* File name is hello_world.c */ #include <stdio.h> int main(void) { int i; printf("Hello world!\n"); } To compile the file hello_world.c from the command line: gcc hello_world.c gcc will then compil...

Feature detection of classes can partly be done with the property_exists and method_exists functions. class MyClass { public $public_field; protected $protected_field; private $private_field; static $static_field; const CONSTANT = 0; public function public_function() {...

Dependency Injection (DI) in the context of using a Dependency Injection Container (DIC) can be seen as a superset of constructor injection. A DIC will typically analyze a class constructor's typehints and resolve its needs, effectively injecting the dependencies needed for the instance execution. ...

A constructor is a special method in a class that is called when an instance of an object is created. It is a regular MATLAB function that accepts input parameters but it also must follow certain rules. Constructors are not required as MATLAB creates a default one. In practice, however, this is a p...

Unlike other programming languages, in a batch file a variable is substituted by its actual value before the batch script is run. In other words, the substitution is made when the script is read into memory by the command processor, not when the script is later run. This enables the use of variable...

Create a new project It can be just a Single View Application. Add the code Create a new Cocoa Touch Class file (File > New > File... > iOS > Cocoa Touch Class). Name it MyCollectionViewCell. This class will hold the outlets for the views that you add to your cell in the storyboard. ...

The following might have undefined behavior due to incorrect pointer alignment: char *memory_block = calloc(sizeof(uint32_t) + 1, 1); uint32_t *intptr = (uint32_t*)(memory_block + 1); /* possible undefined behavior */ uint32_t mvalue = *intptr; The undefined behavior happens as the pointer...

The following code has undefined behavior: char buffer[6] = "hello"; char *ptr1 = buffer - 1; /* undefined behavior */ char *ptr2 = buffer + 5; /* OK, pointing to the '\0' inside the array */ char *ptr3 = buffer + 6; /* OK, pointing to just beyond */ char *ptr4 = buffer + 7; /* un...

While there are many different control sequences for io:format and io_lib:format, most of the time you'll use only three different ones: ~s, ~p and ~w. ~s The ~s is for strings. It prints strings, binaries and atoms. (Anything else will cause a badarg error.) It doesn't quote or escape anything...