Nodejs Object Bind map(f)

Method Source Code

"use strict";//from ww w .  ja  v  a2 s.co  m

var map = function(f, thing) {
  if(thing.map) {
    return thing.map(f);
  }

  throw new Error("Object given does not implement map");
};

var square = function(x) {
  return x * x;
};

console.log(map(square, [1,2,3]));

Object.prototype.map = function(f) {
  var result = {}, that = this;

  Object.keys(this).forEach(function(key) {
    result[key] = f(key, that[key]);
  });

  return result;
};

var obj = {
  "courses" : ["Programming 101", "Frontend JavaScript", "Core Java"]
};

console.log(map(function(key, value) {
  return map(function(course) {
    return course + "!";
  }, value);
}, obj));


String.prototype.map = function(f) {
  var result = this.split("");
  return map(f, result).join("");
};

console.log(map(function(ch) {
  return ch.toUpperCase();
}, "javascript"));

Related

1. bind(method)

   Object.prototype.bind = function(method){
     var object  = this;
     return function(){
           method.apply(object, arguments);
       };
   

2. bind(prop)

   Object.prototype.bind = function (prop) {
       var self = this;
       var method = this[prop];
       return function () {
     return method.apply(self, arguments);
       };
   };
   

3. map(cb, thisArg)

   Object.prototype.map = function(cb, thisArg) {
     thisArg = thisArg || this;
     var that = this;
     Object.getOwnPropertyNames(this).map(function(name) {
       cb(name, that[name]);
     });
     return this;
   };
   

4. map(obj, callback)

   "use strict";
   Object.map = function(obj, callback) {
       return Object.keys(obj).map(key => callback(obj[key], key));
   

5. mapWithKey(f)

   Object.prototype.mapWithKey = function(f) {
     var result = new Array();
     for (var key in this) {
       result[result.length] = f(key, this[key]);
     };
     return result;
   };
   

6. addMixin(mixin)

   Object.prototype.addMixin = function (mixin) {    
     for (var prop in mixin) {
       if (mixin.hasOwnProperty(prop)) {
         this.prototype[prop] = mixin[prop];
   };