Tutorial by Examples: an

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

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...

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

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

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...

<script src="example.js"></script> The src attribute works like the href attribute on anchors: you can either specify an absolute or relative URL. The example above links to a file inside the same directory of the HTML document. This is typically added inside the <head&gt...

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...

The content mode property of a view tells how its content should be laid out. In the Interface Builder, the various modes can be selected in the Attributes Inspector. Let's use two image views to see how the various modes work. Scale to Fill The image heights and widths are stretched to mat...

Using generics to define the type in instanceof Consider the following generic class Example declared with the formal parameter <T>: class Example<T> { public boolean isTypeAString(String s) { return s instanceof T; // Compilation error, cannot use T as class type here ...

If you are inside a folder of a git repository it might be nice to show the current branch you are on. In ~/.bashrc or /etc/bashrc add the following (git is required for this to work): function prompt_command { # Check if we are inside a git repository if git status > /dev/null 2>&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...

Sometimes you need to call a Tcl command from your expression. For example, supposing you need the length of a string in it. To do that, you just use a [...] sequence in the expression: set halfTheStringLength [expr { [string length $theString] / 2 }] You can call any Tcl command this way, but i...

CSS div { width: 200px; height: 200px; background: url(http://lorempixel.com/200/200/abstract/6); mask-image: radial-gradient(circle farthest-side at center, transparent 49%, white 50%); /* check remarks before using */ } HTML In the above example, a transparent circle is created...

$ git log master # specify branch $ git show v1.0 # specify tag $ git show HEAD # specify current branch $ git show origin # specify default remote-tracking branch for remote 'origin' You can specify revision using a symbolic ref name, which includes branches (for example 'master'...

$ git log @{upstream}.. # what was done locally and not yet published, current branch $ git show master@{upstream} # show upstream of branch 'master' The suffix @{upstream} appended to a branchname (short form <branchname>@{u}) refers to the branch that the branch specified by branc...

$ 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...

In some cases the behavior of a command depends on whether it is given branch name, tag name, or an arbitrary revision. You can use "de-referencing" syntax if you need the latter. A suffix ^ followed by an object type name (tag, commit, tree, blob) enclosed in brace pair (for example v0.9...

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...

Jetty is a Java-based, open-source project providing a HTTP server/client and javax.servlet container. Jetty also provides support for HTTP/2, JMX, JNDI, OSGi JAAS and other integrations. Jetty can be deployed as a standard distribution package or as an embeddable web server, allowing users to custo...