Recent Work with Javascript Experiments

experiments.js

console.log("========================");
//Closures
(function(x) {
  return function(y) {
    return function(z) {
      console.log("x "+x);
      console.log("y "+y);
      console.log("z "+z);
      console.log(x + y + 3);
      return x + y + z;
    };
  };
})(1)(2)(3);
console.log("========================");
//function X Closures
(function(x) {
  console.log(x);
  return (function(y){
    console.log(y+x);
    return x+y;
  });
})(1)(2);
console.log("========================");
var num = function jeff(x) {
  return (function(y){
    return x + y;
  });
};
var num2 = num(2);
var num3 = num2(3);
console.log("num2: "+num2);
console.log("num3: "+num3);
console.log("========================");

(function(w){
  console.log(w);
  return (function(x){
    console.log(x);
    return (function(y){
      console.log(y);
      return (function(z){
        console.log(z);
        console.log(w+x+y+z);
        return w +x + y + z;
      });
    });
  });
})(1)(2)(3)(4);
console.log("========================");

(function (x) {
  return function (x,y){
    return function (w,z){
      return function(w){
        return x + y + z;
      };
    };
  };
})();
console.log("========================");
(function (Pi) {
  return function(diameter){
    console.log(diameter*Pi);
    return diameter*Pi;
  };
})(3.14)(2);
console.log("========================");
(function (diameter) {
  return function(Pi){
    console.log(diameter*Pi);
    console.log(diameter);
    return diameter*Pi;
  };
})(2)(3.14);
console.log("========================");
(function (diameter) {
  var Pi = 3.14;
  console.log(diameter * Pi);
  return diameter * Pi;
})(3);
console.log("========================");
(function (d) { 
  var calc = function (diameter) {
    var Pi = 3.14;
    console.log(diameter * Pi);
    return diameter * Pi;
  };
  console.log ("Circumference: " +calc(d));
  return "Circumference: " + calc(d);
})(3);
console.log("========================");
(function (d) {
  var Pi = 3.14,
      calc = function (diameter) {
        console.log(diameter * Pi);
        return diameter * Pi;
      };
  return "Circumference: " + calc(d);
})(4);
console.log("========================");
function foobar () {
  (function() { 
    
    var foo = 'foo',
        bar = 'bar';
    console.log(foo +" " + bar);
  })();
}
foobar();
console.log("========================");
var bindingName = function actualName() {
};
console.log(bindingName.name);
console.log("========================");
// naming of variables, even is bound within function itself but not outside (great for recursion)
var fn = function even (n) {
  if (n===0){
    return true;
  }
  else return !even(n-1);
};
console.log(fn(5));
console.log(fn(2));
console.log("========================");
// Function Declarations - binds name in environment to a named function 

function someName2() {
  //...
}
//behaves similiar to:
var someName3 = function someName3(){
  // ...
};
// this doesn't work:
/* (function() {
  var someName;
  return someName;
  someName = function someName(){
  };
 })(); */

// this will work: declare without the var

/* console.log((function() {
  return someName;
  
  function someName(){
  }
}))(); */

// as if you wrote: 

/* (function(){
  var someName = function someName(){
    // ...
  };
  return someName;
})(); */

// function declaration CANNOT exist inside of any expression, otherwise it's a function express: 

//function declaration:
function trueDat() { return true; }

//function expression (paranthesis)
(function trueDat() { return true; })();

//high order functions - functions that either take functions/arguments or return function/both are high order

/* function repeat(num, fn){
  var i, value;
  for (i=1;i<num; ++i)
    value = fn(i);
  return value;
} */

function compose (a,b){
  return function(c){
    console.log(c);
    return a(b(c));
  };
}
function addOne (number) {
  return number + 1;
}
function doubleOf(number) {
  return number *2;
}
function doubleOfAddOne(number) {
  return doubleOf(addOne(number));
}
console.log(doubleOfAddOne(5));

// set doubleOfAddTwo to compose, doubleofAddTwo(5) is passed through compose into the return function and then b(c) runs, a(c) runs on the result of b(c)
var doubleOfAddTwo = compose(doubleOf, addOne);
console.log(doubleOfAddTwo(5));
console.log("======================");
// function decorators:

function not (fn) {
  return function(argument) {
    return !fn(argument);
  };
}
function something(x) {
  return x !== null;
}
console.log(something(5));

function nothing(x) {
  return !something(x);
}
console.log(nothing(4));
var nothing = not(something);
console.log(nothing);