Tutorial by Examples: en

Due to the way the Tcl language parser works, braces in the code must be properly matched. This includes the braces in comments. proc hw {} { # this { code will fail puts {hello world} } A missing close-brace: possible unbalanced brace in comment error will be thrown. proc hw {} { ...

You can use the following code for going back and forward. if (!function_exists('mb_internal_encoding')) { function mb_internal_encoding($encoding = NULL) { return ($from_encoding === NULL) ? iconv_get_encoding() : iconv_set_encoding($encoding); } } if (!function_exists('mb_c...

Optimizing by using the right data structures at the right time can change the time-complexity of the code. // This variant of stableUnique contains a complexity of N log(N) // N > number of elements in v // log(N) > insert complexity of std::set std::vector<std::string> stableUnique...

A variable which is declared as transient will not be serialized during object serialization. public transient int limit = 55; // will not persist public int b; // will persist

This worked for me to move from Ubuntu 12.04 (Jenkins ver. 1.628) to Ubuntu 16.04 (Jenkins ver. 1.651.2). I first installed Jenkins from the repositories. Stop both Jenkins servers Copy JENKINS_HOME (e.g. /var/lib/jenkins) from the old server to the new one. From a console in the new serve...

(defun print-entry (key value) (format t "~A => ~A~%" key value)) (maphash #'print-entry *my-table*) ;; => NIL Using maphash allows to iterate over the entries of a hash table. The order of iteration is unspecified. The first argument is a function accepting two parameters: ...

String#at Returns a substring of a string object. Same interface as String#[]. str = "hello" str.at(0) # => "h" str.at(1..3) # => "ell" str.at(-2) # => "l" str.at(-2..-1) # => "lo" str.at(5) # => nil str.at(5..-...

String#to_time Converts a string to a Time value. The form parameter can be either :utc or :local, defaults to :local. "13-12-2012".to_time # => 2012-12-13 00:00:00 +0100 "06:12".to_time # => 2012-12-13 06:12:00 +0100 "2012-12-13 06...

String#exclude? The inverse of String#include? "hello".exclude? "lo" # => false "hello".exclude? "ol" # => true "hello".exclude? ?h # => false

String#squish Returns a version of the given string without leading or trailing whitespace, and combines all consecutive whitespace in the interior to single spaces. Destructive version squish! operates directly on the string instance. Handles both ASCII and Unicode whitespace. %{ Multi-line ...

String#pluralize Returns of plural form of the string. Optionally takes a count parameter and returns singular form if count == 1. Also accepts a locale parameter for language-specific pluralization. 'post'.pluralize # => "posts" 'octopus'.pluralize # => &quot...

const foobar = `foo bar` encoding := base64.StdEncoding encodedFooBar := make([]byte, encoding.EncodedLen(len(foobar))) encoding.Encode(encodedFooBar, []byte(foobar)) fmt.Printf("%s", encodedFooBar) // Output: Zm9vIGJhcg== Playground

str := base64.StdEncoding.EncodeToString([]byte(`foo bar`)) fmt.Println(str) // Output: Zm9vIGJhcg== Playground

Activity class takes care of creating a window for you in which you can place your UI with setContentView. There are three setContentView methods: setContentView(int layoutResID) - Set the activity content from a layout resource. setContentView(View view) - Set the activity content to an explic...

The 'Golden' method minimizes a unimodal function by narrowing the range in the extreme values import numpy as np from scipy.optimize import _minimize from scipy import special import matplotlib.pyplot as plt x = np.linspace(0, 10, 500) y = special.j0(x) optimize.minimize_scalar(special.j0,...

Brent's method is a more complex algorithm combination of other root-finding algorithms; however, the resulting graph isn't much different from the graph generated from the golden method. import numpy as np import scipy.optimize as opt from scipy import special import matplotlib.pyplot as plt ...

Think this could example could be better but you get the gist import numpy as np from scipy.optimize import _minimize from scipy import special import matplotlib.pyplot as plt from matplotlib import cm from numpy.random import randn x, y = np.mgrid[-2:2:100j, -2:2:100j] plt.pcolor(x, y, op...

Creating a Window with OpenGL context (extension loading through GLEW): #define GLEW_STATIC #include <GL/glew.h> #include <SDL2/SDL.h> int main(int argc, char* argv[]) { SDL_Init(SDL_INIT_VIDEO); /* Initialises Video Subsystem in SDL */ /* Setting up OpenGL version a...

Create User Model # Schema: User(token:string, auth_token:string) class User < ActiveRecord::Base has_secure_token has_secure_token :auth_token end Now when you create a new user a token and auth_token are automatically generated user = User.new user.save user.token # => "p...

The entries() method returns a new Array Iterator object that contains the key/value pairs for each index in the array. 6 var letters = ['a','b','c']; for(const[index,element] of letters.entries()){ console.log(index,element); } result 0 "a" 1 "b" 2 "c"...