Tutorial by Examples: ed

With the RequireQualifiedAccess attribute, union cases must be referred to as MyUnion.MyCase instead of just MyCase. This prevents name collisions in the enclosing namespace or module: type [<RequireQualifiedAccess>] Requirements = None | Single | All // Uses the DU with qualified acc...

public class IntStack { private IntStackNode head; // IntStackNode is the inner class of the class IntStack // Each instance of this inner class functions as one link in the // Overall stack that it helps to represent private static class IntStackNode { privat...

When creating a nested class, you face a choice of having that nested class static: public class OuterClass1 { private static class StaticNestedClass { } } Or non-static: public class OuterClass2 { private class NestedClass { } } At its core, static nested c...

Declared variable without a value will have the value undefined var a; console.log(a); // logs: undefined Trying to retrieve the value of undeclared variables results in a ReferenceError. However, both the type of undeclared and unitialized variables is "undefined": var a; console...

variables var = 50 -- a global variable print(var) --> 50 do local var = 100 -- a local variable print(var) --> 100 end print(var) --> 50 -- The global var (50) still exists -- The local var (100) has gone out of scope and can't be accessed any longer. types num = 20 -- a ...

Creating a database in a particular location. If we dont specify any location for database its created in warehouse directory. CREATE DATABASE IF NOT EXISTS db_name COMMENT 'TEST DATABASE' LOCATION /PATH/HDFS/DATABASE/;

Given a file using ; as a column delimiter. We compute the median of the values in the second column with the following program, written for GNU awk. The provided input is the list of grades of a student group: gawk -F';' '{ sample[NR] = $2 } END { asort(sample); if(NR % 2 == 1) { p...

Fortran originally was designed for a fixed format form based on an 80 column punched card: Yes: This is a line of the author's own code These were created on a card punch machine, much like this: Images are original photography by the author The format, as shown on the illustrated sample ca...

It is a good practice to provide expression string arguments as braced strings. The heading "Double Substitution" outlines important reasons behind the same. The expr command evaluates an operator-based expression string to calculate a value. This string is constructed from the arguments ...

Sometimes it is required to display a notification at a specific time, a task that unfortunately is not trivial on the Android system, as there is no method setTime() or similiar for notifications. This example outlines the steps needed to schedule notifications using the AlarmManager: Add a Broa...

$ mkdir 20{09..11}-{01..12} Entering the ls command will show that the following directories were created: 2009-01 2009-04 2009-07 2009-10 2010-01 2010-04 2010-07 2010-10 2011-01 2011-04 2011-07 2011-10 2009-02 2009-05 2009-08 2009-11 2010-02 2010-05 2010-08 2010-11 2011-02 2011-05 2011-08 2011...

The default rules require Authentication. They allow full read and write access to authenticated users of your app. They are useful if you want data open to all users of your app but don't want it open to the world. // These rules require authentication { "rules": { ".read&...

Here's an example of a rule that gives each authenticated user a personal node at /users/$user_id where $user_id is the ID of the user obtained through Authentication. // These rules grant access to a node matching the authenticated // user's ID from the Firebase auth token { "rules"...

First, create a key file, e.g., vault_pass_file, which ideally contains a long sequence of random characters. In linux systems you could use pwgen to create a random password file: pwgen 256 1 > vault_pass_file Then, use this file to encrypt sensitive data, e.g., groups_vars/group.yml: ANSI...

With Vault you can also encrypt non-structured data, such as private key files and still be able to decrypt them in your play with the lookup module. --- - name: Copy private key to destination copy: dest=/home/user/.ssh/id_rsa mode=0600 content=lookup('pipe', 'ANSIBLE_VAULT_PA...

You can run a play which relies on vault-encrypted templates by using the local_action module. --- - name: Decrypt template local_action: "shell {{ view_encrypted_file_cmd }} {{ role_path }}/templates/template.enc > {{ role_path }}/templates/template" changed_when: False - ...

Grant Vibration Permission before you start implement code, you have to add permission in android manifest : <uses-permission android:name="android.permission.VIBRATE"/> Import Vibration Library import android.os.Vibrator; Get instance of Vibrator from Context Vibrator vibr...

proc myproc {} { puts "hi" } myproc # => hi An empty argument list (the second argument after the procedure name, "myproc") means that the procedure will not accept arguments.

proc myproc {alpha beta} { ... set foo $alpha set beta $bar ;# note: possibly useless invocation } myproc 12 34 ;# alpha will be 12, beta will be 34 If the argument list consists of words, those will be the names of local variables in the procedure, and their initi...

### Definition proc myproc {alpha {beta {}} {gamma green}} { puts [list $alpha $beta $gamma] } ### Use myproc A # => A {} green myproc A B # => A B green myproc A B C # => A B C This procedure accepts one, two, or three arguments: those parameters whose names are the fi...