dinks

# Rails
nil.nil? # true

"".empty?    # true
[].empty?    # true
{}.empty?    # true
nil.empty?   # NoMethodError
"  ".empty?  # false

nil.blank?   # true

dinks

# https://blog.engineyard.com/2015/five-ruby-methods-you-should-be-using

def convert_to_hours(minutes)
  hours = 0
  until (0..60).include? minutes
    hours -= (60 <=> minutes)
    minutes += 60 * (60 <=> minutes)
  end
  {
    hours: hours,

dinks

Mac OS X 10.9 Mavericks

Custom recipe to get OS X 10.9 Mavericks running from scratch, setup applications and developer environment. I use this gist to keep track of the important software and steps required to have a functioning system after a semi-annual fresh install.

Install Software

The software selected is software that is "tried and true" --- software I need after any fresh install. I often install other software not listed here, but is handled in a case-by-case basis.

Install from App Store

dinks

// http://madebyevan.com/obscure-cpp-features/
// ptr[3] is *(ptr + 3) and is therefore 3[ptr]

// Is this:
// 1) A variable of type std::string initialized to a std::string()?
// 2) The declaration of a function that returns a std::string and has one argument,
//    which is a pointer to a function with no arguments that returns a std::string?
std::string foo(std::string());

// Is this:

dinks

nil.to_i.nil? # false
"x".to_i == 0 # true
"12xhdhsjh".to_i == 12 # true

# Rails 4
{surprise: true, 'surprise' => false}.symbolize_keys
# {:surprise => false} 

{surprise: true, 'surprise' => false}.symbolize_keys!
# {:surprise => false}

dinks

// '0', 0, and 0.0 are false, but '0.0' is true

// If a function returns an Array, you just can not write
$first_element = function_returns_array()[0]; //Syntax ERROR!!
$first_element = ( function_returns_array() )[0]; //This neither!!
//Instead you must write
$a = function_returns_array();
$first_element = $a[0];

dinks

// https://remysharp.com/2014/11/19/my-five-promise-patterns
// Clean shallow chains
var writeFile = Promise.denodeify(fs.writeFile);
writeFile(filename, content)
  .then(addDBUser)
  .then(dns)
  .then(configureHeroku)
  .then(function () {
    console.log('All done');
  });

dinks

// https://wiki.theory.org/YourLanguageSucks

// + Always does a valueOf and then a toString 
// because + could only be done with integers and strings
// Number and String are the code conversions

[] + [] // ""
// Explaination
// ([]).valueOf() returns the same array and then ([]).toString() returns ""

dinks

var x = 'global';

function indirectEval() {
  'use strict';
  var x = 'local';
  
  console.log(eval('x')); // Local

  // Call eval in a different way
  console.log(eval.call(null, 'x')); // global

dinks

function t1(a, b, c) {
  console.log(a, b, c);
}

t1(1, 2, 3); // 1 2 3

t2 = t1.bind(undefined, 10);
t2(2, 3); // 10 2 3

t3 = t2.bind(undefined, 20); // t3 = t1.bind(undefined, 10, 20);