Tutorial by Examples: ti

a, b = 2, 3 (a ** b) # = 8 pow(a, b) # = 8 import math math.pow(a, b) # = 8.0 (always float; does not allow complex results) import operator operator.pow(a, b) # = 8 Another difference between the built-in pow and math.pow is that the built-in po...

One method is available for counting the number of occurrences of a sub-string in another string, str.count. str.count(sub[, start[, end]]) str.count returns an int indicating the number of non-overlapping occurrences of the sub-string sub in another string. The optional arguments start and end ...

Routes are defined in config/routes.rb. They are often defined as a group of related routes, using the resources or resource methods. resources :users creates the following seven routes, all mapping to actions of UsersController: get '/users', to: 'users#index' post '/users', ...

The C language has three mandatory real floating point types, float, double, and long double. float f = 0.314f; /* suffix f or F denotes type float */ double d = 0.314; /* no suffix denotes double */ long double ld = 0.314l; /* suffix l or L denotes long double */ /* the differen...

Dictionaries are an unordered collection of keys and values. Values relate to unique keys and must be of the same type. When initializing a Dictionary the full syntax is as follows: var books : Dictionary<Int, String> = Dictionary<Int, String>() Although a more concise way of initia...

Add a key and value to a Dictionary var books = [Int: String]() //books = [:] books[5] = "Book 5" //books = [5: "Book 5"] books.updateValue("Book 6", forKey: 5) //[5: "Book 6"] updateValue returns the original value if one exists or nil. let previous...

The <article> element contains self-contained content like articles, blog posts, user comments or an interactive widget that could be distributed outside the context of the page, for example by RSS. When article elements are nested, the contents of the inner article node should be related t...

Use new Date() to generate a new Date object containing the current date and time. Note that Date() called without arguments is equivalent to new Date(Date.now()). Once you have a date object, you can apply any of the several available methods to extract its properties (e.g. getFullYear() to get t...

Jsoup can be used to extract links and email address from a webpage, thus "Web email address collector bot" First, this code uses a Regular expression to extract the email addresses, and then uses methods provided by Jsoup to extract the URLs of links on the page. public class JSoupTest {...

After starting a merge, you might want to stop the merge and return everything to its pre-merge state. Use --abort: git merge --abort

This example uses the Cars Table from the Example Databases. UPDATE Cars SET Status = 'READY' This statement will set the 'status' column of all rows of the 'Cars' table to "READY" because it does not have a WHERE clause to filter the set of rows.

This example uses the Cars Table from the Example Databases. UPDATE Cars SET Status = 'READY' WHERE Id = 4 This statement will set the status of the row of 'Cars' with id 4 to "READY". WHERE clause contains a logical expression which is evaluated for each row. If a...

This example uses the Cars Table from the Example Databases. UPDATE Cars SET TotalCost = TotalCost + 100 WHERE Id = 3 or Id = 4 Update operations can include current values in the updated row. In this simple example the TotalCost is incremented by 100 for two rows: The TotalCost of Car #3 i...

The general syntax for declaring a one-dimensional array is type arrName[size]; where type could be any built-in type or user-defined types such as structures, arrName is a user-defined identifier, and size is an integer constant. Declaring an array (an array of 10 int variables in this case) i...

Accessing array values is generally done through square brackets: int val; int array[10]; /* Setting the value of the fifth element to 5: */ array[4] = 5; /* The above is equal to: */ *(array + 4) = 5; /* Reading the value of the fifth element: */ val = array[4]; As a side effect of...

Git will usually open an editor (like vim or emacs) when you run git commit. Pass the -m option to specify a message from the command line: git commit -m "Commit message here" Your commit message can go over multiple lines: git commit -m "Commit 'subject line' message here Mor...

Extensions can contain functions and computed/constant get variables. They are in the format extension ExtensionOf { //new functions and get-variables } To reference the instance of the extended object, self can be used, just as it could be used To create an extension of String that adds ...

Extensions can contain convenience initializers. For example, a failable initializer for Int that accepts a NSString: extension Int { init?(_ string: NSString) { self.init(string as String) // delegate to the existing Int.init(String) initializer } } let str1: NSString = &qu...

import operator reduce(operator.mul, [10, 5, -3]) # Out: -150

# First falsy element or last element if all are truthy: reduce(lambda i, j: i and j, [100, [], 20, 10]) # = [] reduce(lambda i, j: i and j, [100, 50, 20, 10]) # = 10 # First truthy element or last element if all falsy: reduce(lambda i, j: i or j, [100, [], 20, 0]) # = 100 reduce(la...