nealalan

### Keybase proof

I hereby claim:

  * I am nealalan on github.
  * I am nealalan (https://keybase.io/nealalan) on keybase.
  * I have a public key whose fingerprint is 0FCD DA82 34C1 BB84 EAA8  5C9C 46A1 0498 3B7C E79A

To claim this, I am signing this object:

nealalan

nealalan

nealalan

JSON: JavaScript Object Notation

• JSON.stringify and JSON.parse

let string = JSON.stringify({squirrel: false,
                             events: ["weekend"]});
console.log(string);
// → {"squirrel":false,"events":["weekend"]}
console.log(JSON.parse(string).events);

nealalan

MATH FUNCTION

• Math.max (maximum)
• Math.min (minimum)
• Math.sqrt (square root)
• Math.PI
• Math.random (decimal)
• Math.floor (rounds down to the nearest whole number)

console.log(Math.floor(Math.random() * 10));
// → 2

nealalan

• function that computes the ϕ coefficient from such an array:

function phi(table) {
  return (table[3] * table[0] - table[2] * table[1]) /
    Math.sqrt((table[2] + table[3]) *
              (table[0] + table[1]) *
              (table[1] + table[3]) *
              (table[0] + table[2]));
}

nealalan

ARRAY SEARCHING FOR OBJECTS

My original questions was: Creating and accessing array of objects in Javascript

ARRAYS

ACCESS

• .push = adds to end
• .pop = removes from end

let sequence = [1, 2, 3];

nealalan

TRANSPILING

• use a tool that converts your newer code into older code equivalent
• ES6 adds a feature called "default parameter values." Transpiling will modify/add the code to work with ES5
• Example:

// IN ES6, USE A DEFAULT VALUE
function foo(a = 2) {
	console.log( a );
}
// PRE ES6 EXPLICITLY CHECK FOR A DEFAULT VALUE AND DEFINE IT

nealalan

POLYFILLING

• taking the definition of a newer feature and producing a piece of code that's equivalent to the behavior, but is able to run in older JS environments.

if (!Number.isNaN) {
	Number.isNaN = function isNaN(x) { return x !== x; };
}

• Use a vetted set of polyfills that you can trust, such as those provided by ES5-Shim and ES6-Shim

nealalan

This is the prompt I am currently using. (Add to ~/.bashrc file.)

#######################################################################################################################
# BEAUTIFY THE COMMAND PROMPT WITH GIT
#######################################################################################################################
# get current branch in git repo
function parse_git_branch() {
 BRANCH=`git branch 2> /dev/null | sed -e '/^[^*]/d' -e 's/* \(.*\)/\1/'`