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Java SE 5 With Java 5 and up, one can use for-each loops, also known as enhanced for-loops: List strings = new ArrayList(); strings.add("This"); strings.add("is"); strings.add("a for-each loop"); for (String string : strings) { System.out.println(string); } For each ...

public class MyActivity extends Activity { private static final String PREFS_FILE = "NameOfYourPrefrenceFile"; // PREFS_MODE defines which apps can access the file private static final int PREFS_MODE = Context.MODE_PRIVATE; // you can use live template "key"...

With this class: class ObjectMemberVsStaticMember { static int staticCounter = 0; int memberCounter = 0; void increment() { staticCounter ++; memberCounter++; } } the following code snippet: final ObjectMemberVsStaticMember o1 = new ObjectMemberVsStati...

Android Studio is the Android development IDE that is officially supported and recommended by Google. Android Studio comes bundled with the Android SDK Manager, which is a tool to download the Android SDK components required to start developing apps. Installing Android Studio and Android SDK tools:...

It is helpful to filter the logcat output because there are many messages which are not of interest. To filter the output, open the "Android Monitor" and click on the drop down on the top-right and select Edit Filter Configuration Now you can add custom filters to show messages which ar...

If you want to take a screenshot from the Android Emulator (2.0), then you just need to press Ctrl + S or you click on the camera icon on the side bar: If you use an older version of the Android Emulator or you want to take a screenshot from a real device, then you need to click on the camera ico...

Once the SDK installed, you can open the AVD Manager from the command line using android avd. You can also access AVD Manager from Android studio using Tools > Android > AVD Manager or by clicking on the AVD Manager icon in the toolbar which is the second in the screenshot below.

private static final String MY_PREF = "MyPref"; // ... SharedPreferences prefs = ...; // ... SharedPreferences.Editor editor = prefs.edit(); editor.putString(MY_PREF, "value"); editor.remove(MY_PREF); editor.apply(); After the apply(), prefs contains "key&q...

The AppCompat support library provides themes to build apps with the Material Design specification. A theme with a parent of Theme.AppCompat is also required for an Activity to extend AppCompatActivity. The first step is to customize your theme’s color palette to automatically colorize your app. I...

A Toolbar is a generalization of ActionBar for use within application layouts. While an ActionBar is traditionally part of an Activity's opaque window decor controlled by the framework, a Toolbar may be placed at any arbitrary level of nesting within a view hierarchy. It can be added by performing t...

Using BufferedReader: System.out.println("Please type your name and press Enter."); BufferedReader reader = new BufferedReader(new InputStreamReader(System.in)); try { String name = reader.readLine(); System.out.println("Hello, " + name + "!"); } catch(I...

The Arrays.asList() method can be used to return a fixed-size List containing the elements of the given array. The resulting List will be of the same parameter type as the base type of the array. String[] stringArray = {"foo", "bar", "baz"}; List<String> stringL...

It is possible to define an array with more than one dimension. Instead of being accessed by providing a single index, a multidimensional array is accessed by specifying an index for each dimension. The declaration of multidimensional array can be done by adding [] for each dimension to a regular a...

For basic prototypes or basic command-line behavior, the following loop comes in handy. public class ExampleCli { private static final String CLI_LINE = "example-cli>"; //console like string private static final String CMD_QUIT = "quit"; //string for exit...

All Swing-related operations happen on a dedicated thread (the EDT - Event Dispatch Thread). If this thread gets blocked, the UI becomes non-responsive. Therefore, if you want to delay an operation you cannot use Thread.sleep. Use a javax.swing.Timer instead. For example the following Timer will re...

In the ActionListener attached to a javax.swing.Timer, you can keep track of the number of times the Timer executed the ActionListener. Once the required number of times is reached, you can use the Timer#stop() method to stop the Timer. Timer timer = new Timer( delay, new ActionListener() { priv...

Following snippet shows an example of passing a method group (as opposed to a lambda) when a delegate is expected. Overload resolution will now resolve this instead of raising an ambiguous overload error due to the ability of C# 6 to check the return type of the method that was passed. using System...

The ArrayIndexOutOfBoundsException is thrown when a non-existing index of an array is being accessed. Arrays are zero-based indexed, so the index of the first element is 0 and the index of the last element is the array capacity minus 1 (i.e. array.length - 1). Therefore, any request for an array e...

The String type provides two methods for converting strings between upper case and lower case: toUpperCase to convert all characters to upper case toLowerCase to convert all characters to lower case These methods both return the converted strings as new String instances: the original String o...

Protected visibility causes means that this member is visible to its package, along with any of its subclasses. As an example: package com.stackexchange.docs; public class MyClass{ protected int variable; //This is the variable that we are trying to access public MyClass(){ var...