Tutorial by Examples

Ant provides some built-in properties Property NameValuebasedirthe absolute path of the project's basedirant.filethe absolute path of the buildfile.ant.versionthe version of Antant.project.default-targetthe name of the currently executing project's default targetant.project.namename of the projecta...

There are two ways to define models in sequelize; with sequelize.define(...), or sequelize.import(...). Both functions return a sequelize model object. 1. sequelize.define(modelName, attributes, [options]) This is the way to go if you'd like to define all your models in one file, or if you want to...

There are two kind of types in Python. Immutable types and mutable types. Immutables An object of an immutable type cannot be changed. Any attempt to modify the object will result in a copy being created. This category includes: integers, floats, complex, strings, bytes, tuples, ranges and frozen...

One of the major use case when a developer needs to take mutability into account is when passing arguments to a function. This is very important, because this will determine the ability for the function to modify objects that doesn't belong to its scope, or in other words if the function has side ef...

There are four ways to work with JavaScript plugins, Ember add-on Import JavaScript plugins globally Consume named AMD plugins Via ember-browserify

Passing by value When a value is passed ByVal, the procedure receives a copy of the value. Public Sub Test() Dim foo As Long foo = 42 DoSomething foo Debug.Print foo End Sub Private Sub DoSomething(ByVal foo As Long) foo = foo * 2 End Sub Calling the above Test...

First, complete the installation and setup to connect your app to Firebase. Then from anywhere in your class, you can write: // Write a message to the database FirebaseDatabase database = FirebaseDatabase.getInstance(); DatabaseReference myRef = database.getReference("message"); myRe...

This behaviour can be extended. Here is a 3-dimensional array: [[[111,112,113],[121,122,123],[131,132,133]],[[211,212,213],[221,222,223],[231,232,233]],[[311,312,313],[321,322,323],[331,332,333]]] As is probably obvious, this gets a bit hard to read. Use backslashes to break up the different dim...

Gradle (All Versions) This method works for all versions of gradle Add the buildscript code at the beginning of your build.gradle file. buildscript { repositories { maven { url "https://plugins.gradle.org/m2/" } } dependencies { classpath "org.example...

Gradle (All Versions) When adding multiple third party plugins you do not need to separate them into different instances of the buildscript(All) or plugin(2.1+) code, new plug ins can be added alongside pre-existing plugins. buildscript { repositories { maven { url "https://plu...

Basic Idea The notation used when describing the speed of your Python program is called Big-O notation. Let's say you have a function: def list_check(to_check, the_list): for item in the_list: if to_check == item: return True return False This is a simple function ...

Operations : Average Case (assumes parameters are randomly generated) Append : O(1) Copy : O(n) Del slice : O(n) Delete item : O(n) Insert : O(n) Get item : O(1) Set item : O(1) Iteration : O(n) Get slice : O(k) Set slice : O(n + k) Extend : O(k) Sort : O(n log n) Multiply : O(nk) x in...

A deque is a double-ended queue. class Deque: def __init__(self): self.items = [] def isEmpty(self): return self.items == [] def addFront(self, item): self.items.append(item) def addRear(self, item): self.items.insert(0,item) def removeFront(self): return self....

Operation : Average Case (assumes parameters generated randomly) : Worst case x in s : O(1) Difference s - t : O(len(s)) Intersection s&t : O(min(len(s), len(t))) : O(len(s) * len(t) Multiple intersection s1&s2&s3&...&sn : : (n-1) * O(l) where l is max(len(s1),...,len(sn)) s...

When using d3.request() or one of the convenience constructors (d3.json, d3.csv, d3.tsv, d3.html and d3.xml) there are many sources for error. There may be problems with the issued request or its response due to network errors, or the parsing might fail if the content is not well-formed. Within the...

Like page caching, action caching caches the whole page. The difference is that the request hits the Rails stack so before filters are run before the cache is served. It's extracted from Rails to actionpack-action_caching gem. A common example is caching of an action that requires authentication: ...

Sample Data: CREATE TABLE table_name ( id, list ) AS SELECT 1, 'a,b,c,d' FROM DUAL UNION ALL -- Multiple items in the list SELECT 2, 'e' FROM DUAL UNION ALL -- Single item in the list SELECT 3, NULL FROM DUAL UNION ALL -- NULL list SELECT 4, 'f,,g' FROM DUAL; -- NULL item...

In config.ini: [DEFAULT] debug = True name = Test password = password [FILES] path = /path/to/file In Python: from ConfigParser import ConfigParser config = ConfigParser() #Load configuration file config.read("config.ini") # Access the key "debug" in "DEF...

Decryption Code public static string Decrypt(string cipherText) { if (cipherText == null) return null; byte[] cipherBytes = Convert.FromBase64String(cipherText); using (Aes encryptor = Aes.Create()) { Rfc2898DeriveBytes pdb = ...

We can use command uname with various options to get complete details of running kernel. uname -a Linux df1-ws-5084 4.4.0-64-generic #85-Ubuntu SMP Mon Feb 20 11:50:30 UTC 2017 x86_64 x86_64 x86_64 GNU/Linux As per man page here few more options Usage: uname [OPTION]... Print certain system inf...