JavaScript: reference

javascript-reference.js

// JavaScript reference

// Operators
// Variables

/**
 * Conditionals
 */

/**
 * Arrays
 */
var myArray = [10, 30, 23];

console.log(myArray[1]); //30

/**
 * Functions
 */
var square = function(length) {
  return length * length;
};


/**
 * Objects
 */

// Literal notation
var frank = {
  name: "Frank",
  age: 29
};

// Constructor notation 
var frank = new Object();
frank.name = "Frank";
frank.age = 29;

// Access properties in objects...
// ...with dot notation
console.log(frank.name);
// ...with bracket notation
console.log(frank["name"]);

// Methods
// ...is function inside a object or constructor
frank.setAge = function (newAge) {
  frank.age = newAge;
}

// Custom constructor
var Person (name, lastName) {
  this.name = name;
  this.lastName  = lastName;
  this.fullName = function() {
    console.log(this.name + " " + this.lastName);
  };
}

var ola = new Person("Ola", "Nordmann"); //Makes a new object with the Person constructor

ola.fullName(); //Use "()" since it is a function/method

// Make a object with the custom constructor 
var frank = new Person ("Frank", 29);

// Typeof
// Check what type of variable it is.
var myString = function(x, y) {
  return x + y;
}

console.log(typeof myString); // would print "function" 

// Has own property
// Check if the property of an object exists. Returns true or false.
console.log(frank.hasOwnProperty("name");

// For in loop
// Check properties in a object
for(var x in frank) {
  console.log(x); // Prints property label                  
  console.log(frank[x]) // Prints property value
}

// OOP

// Prototype
// Add a default method to a constructor
className.prototype.newMethod = function() {
statements; 
};

// Private and public properties
function Person(first, last) {
  this.first = first; //Public properies
  this.last = last;
  var money = 3100; //Private propery
  var loan = function() { //Private method
    //code
  }
}