Cheatsheet going through all Javascript programming basics (that you already know in ruby!)

cheatsheet.js

// 1 ------------ Basics ------------

// console.log
console.log("hello london!");

// variable / typeof
var name = "Seb Saunier";
var lastName = "Paillard";
var age = 17;
var weight= 72.6;
console.log(typeof(lastName));
console.log(typeof(age));
console.log(typeof(weight));

// 2 ------------ Array / Object ------------

// Array
var beatles = ["paul", "john", "ringo", "george"];
console.log(beatles[2]);

// Object (like ruby hash)
var person = { name: 'bob', age: 42 } // same as { 'name': 'bob', 'age': 42 }
console.log(person["name"]);
console.log(person.name);

// 3 ------------ if / else if / else ------------

if (age >= 21) {
  console.log("You can be president");
} else if (age > 18) {
  console.log("You can vote!");
} else {
  console.log("Can't vote yet");
}

// 4 ------------ loop (for / forEach / Object.keys) ------------

// for
for (var i = 0; i <= 10; i += 2) {
  console.log(i);
}
for (var i = 0; i < beatles.length; i += 1) {
  console.log(beatles[i]);
}

// forEach
beatles.forEach(function(beatle) {
  console.log(beatle);
});

// Object.keys
var instruments = { "john": "guitar", "paul": "bass", "ringo": "drums", "george": "guitar" };
Object.keys(instruments).forEach(function(beatle) {
  console.log(beatle + " played the " + instruments[beatle]);
});

// 5 ------------ define function ------------

function fullName(firstName, lastName) {
  return firstName + " " + lastName;
}
var fullName = function(firstName, lastName) {
  return firstName + " " + lastName;
}
var result = fullName("seb", "saunier");
console.log(result);

// 6 ------------ define class ------------

var Person = function(firstName, lastName) {
  this.firstName = firstName;
  this.lastName = lastName;
}

Person.prototype.fullName = function() {
  return this.firstName + " " + this.lastName;
}

var romain = new Person("Romain", "Paillard");
console.log(romain.fullName());