Tutorial by Examples: ce

The last common use of HTTP APIs is to obtain a list of existing resources on the server. Lists like this should be obtained using GET requests, since they only retrieve data. The server should return 200 OK if it can supply the list, or an appropriate error code if not. Listing our employees, the...

A cross-origin request must be sent including the Origin header. This indicates from where the request originated. For example, a cross-origin request from http://example.com to http://example.org would look like this: GET /cors HTTP/1.1 Host: example.org Origin: example.com The server will us...

The most important use of ranges is to express a sequence Syntax: (begin..end) => this construct will include end value (begin...end) => this construct will exclude end value or Range.new(begin,end,exclude_end) => exclude_end is by default false Most important end value must be gr...

When we want to count the number of items in an iterable, that meet some condition, we can use comprehension to produce an idiomatic syntax: # Count the numbers in `range(1000)` that are even and contain the digit `9`: print (sum( 1 for x in range(1000) if x % 2 == 0 and '9' in str...

defmodule Processes do def receiver do receive do {:ok, val} -> IO.puts "Received Value: #{val}" _ -> IO.puts "Received something else" end end end iex(1)> pid = spawn(Processes, ...

Recursion can be used to receive multiple messages defmodule Processes do def receiver do receive do {:ok, val} -> IO.puts "Received Value: #{val}" _ -> IO.puts "Received something else" end...

For a function or subroutine to be useful it has to be referenced. A subroutine is referenced in a call statement call sub(...) and a function within an expression. Unlike in many other languages, an expression does not form a complete statement, so a function reference is often seen in an ass...

You create new ScriptableObject instances through ScriptableObject.CreateInstance<T>() T obj = ScriptableObject.CreateInstance<T>(); Where T extends ScriptableObject. Do not create ScriptableObjects by calling their constructors, ie. new ScriptableObject(). Creating ScriptableO...

Hash references are scalars which contain a pointer to the memory location containing the data of a hash. Because the scalar points directly to the hash itself, when it is passed to a subroutine, changes made to the hash are not local to the subroutine as with a regular hash, but instead are global...

Ansible is best used from a checkout. It runs as you (not root) and it has minimal python dependencies. Python pip dependency install with pip: sudo pip install paramiko PyYAML Jinja2 httplib2 six Next, clone the Ansible repo from GitHub: cd ~/Documents git clone git://github.com/ansible/ans...

You can obtain information about EC2 instances using: aws ec2 describe-instances You can obtain information about specific EC2 instances using: aws ec2 describe-instances --instance-ids ... where ... contains one or more instance identifiers. For example: aws ec2 describe-instances --instan...

Note: I am assuming that debugfs is mounted under /sys/kernel/debug If not, try: mount -t debugfs none /sys/kernel/debug Change into the tracing directory: cd /sys/kernel/debug/tracing/ Make sure the function tracer is disabled: echo nop > current_tracer Enable all I2C events: echo ...

This is the first phase of referencing. Essentially when you assign by reference, you're allowing two variables to share the same value as such. $foo = &$bar; $foo and $bar are equal here. They do not point to one another. They point to the same place (the "value"). You can also...

Occasionally there comes time for you to implicitly return-by-reference. Returning by reference is useful when you want to use a function to find to which variable a reference should be bound. Do not use return-by-reference to increase performance. The engine will automatically optimize this o...

This allows you to pass a variable by reference to a function or element that allows you to modify the original variable. Passing-by-reference is not limited to variables only, the following can also be passed by reference: New statements, e.g. foo(new SomeClass) References returned from functi...

Const baseString As String = "Foo Bar" Dim containsBar As Boolean Dim posB As Long posB = InStr(1, baseString, "B", vbBinaryCompare) 'posB = 5

Const baseString As String = "Foo Bar" Dim containsBar As Boolean 'Find the position of the last "B" Dim posX As Long 'Note the different number and order of the paramters for InStrRev posX = InStrRev(baseString, "X", -1, vbBinaryCompare) 'posX = 0

'Trim the leading and trailing spaces in a string Const paddedText As String = " Foo Bar " Dim trimmedText As String trimmedText = Trim$(paddedText) 'trimmedText = "Foo Bar"

Build.VERSION_CODES is an enumeration of the currently known SDK version codes. In order to conditionally run code based on the device's Android version, use the TargetApi annotation to avoid Lint errors, and check the build version before running the code specific to the API level. Here is an exa...

An Interface's function known as a "contract" of functionality. It means that it declares properties and methods but it doesn't implement them. So unlike classes Interfaces: Can't be instantiated Can't have any functionality Can only contain methods * (Properties and Events are metho...