JavaScript.js

// The var keyword creates a new variable in the current scope. That means if var is used outside a function, that variable has a global scope. If var is used inside a function, that variable has a local scope.

/* Math */
	Math.random() * i // random float from 0 to i
	Math.floor()

/* isNan */
	/* Be careful: if you call isNaN on a string that looks like a number, like '42', JavaScript will try to help by automatically converting the string '42' to the number 42 and return false (since 42 is a number). */
	isNaN('berry'); // => true
	isNaN(NaN); // => true
	isNaN(undefined); // => true
	isNaN(42);  // => false

isAck = confirm("You are now leaving the site")
name = prompt("What's your name?", "placeholder text")
console.log()

/* typeof */
	typeof someObject // returns "number", "string", "function", "object"

/* Arrays */
	var mix = [42, true, "towel"]; // heterogeneous array: a mixture of data types
	[1,2,3].length == 3 

/* Strings */
	/*jshint multistr:true */
	var text = "Hey, how are you \
	doing? My name is Emily.";
	(2.333333).toFixed(2) == '2.33';
	"string".length == 6
	"some word".substring(x, y) // if single paramter, will get from starting position till end of string
	"string".toUpperCase();

/* Switch */
	switch(lunch){
	  case 'sandwich':
	    console.log("Sure thing! One sandwich, coming up.");
	    break;
	  case 'soup':
	    console.log("Got it! Tomato's my favorite.");
	    break;
	  case 'salad':
	    console.log("Sounds good! How about a caesar salad?");
	    break;
	  case 'pie':
	    console.log("Pie's not a meal!");
	    break;
	  default:
	    console.log("Huh! I'm not sure what " + lunch + " is. How does a sandwich sound?");
	}

/* functions */
	var myFunc = function (param){
	    // doSum
	};
	function myfunc (param){

	};

/* Objects */
	var obj = {}	// literal notation
	var obj = new Object();	// constructor notation
	obj.attr1 = true
	obj.attr1			// dot notation
	obj['attr1']	// bracket notation. Note string can be replaced by a variable. i.e. key='attr1'; obj[key];
	obj.myFunc = function(param){
		console.log(this.attr1); // doSum. This refers to whichever object that calls the function
	};

	obj.hasOwnProperty('name');	// boolean: checks if obj has the property 'name'

	/* iterate through keys */
	for(var key in obj) {
    console.log(key);	// doSum
  }

  /* Constructors */
	function Person(name, age) {
		this.name = name;						// public property
		this.age = age;							// public property
		this.myFunc = function (){	// public function
			//doSum
		};
		var gender = 'male';				// private property (can be accessed by public methods)
	}
	var bill = new Person("Bill Gates", 60);

	/* Prototypes */
	Person.prototype.myFunc = function(){	// adds function myFunc to all Person instances
		//doSum
	};

	/* Inheritance */
	function Animal(name, numLegs) {
    this.name = name;
    this.numLegs = numLegs;
    this.isAlive = true;
}
function Penguin(name) {
    this.name = name;
    this.numLegs = 2;
}
Penguin.prototype = new Animal();
function Emperor(name) {
    this.name = name;
    this.saying = "Waddle waddle";
}
Emperor.prototype = new Penguin();

/* loops */
	for (var counter = 1; counter < 6; counter++) {
		console.log(counter);
	}

/* arrays */
	var arrayName = [data, data, data];
	array.push(item)