Code style

Author: tshemsedinov

JavaScript/1-mixin-function.js

@@ -1,8 +1,8 @@
 'use strict';
 
-let g1 = {};
-let g2 = {};
-let g3 = { area: 300 };
+const g1 = {};
+const g2 = {};
+const g3 = { area: 300 };
 
 // Add property area to g2
 g2.area = 200;
@@ -26,7 +26,7 @@ console.log(g1.calculateCost(5));
 console.log(g2.calculateCost(5));
 console.log(g3.calculateCost(5));
 
-let t1 = setTimeout(function() {
+const t1 = setTimeout(() => {
   console.log('Hello from timer');
 }, 1000);
 

JavaScript/2-mixin-extend.js

@@ -11,17 +11,17 @@ function extend(obj, mixin) {
 }
 */
 
-let extend = (obj, mixin) => (
+const extend = (obj, mixin) => (
   Object.keys(mixin).forEach(key => obj[key] = mixin[key]), obj
 );
 
-let obj1 = { name: 'Marcus Aurelius', city: 'Rome', born: 121 };
+const obj1 = { name: 'Marcus Aurelius', city: 'Rome', born: 121 };
 
-let mix1 = {
-  toString: function() {
+const mix1 = {
+  toString() {
     return this.name + ' was born in ' + this.city + ' in ' + this.born;
   },
-  age: function() {
+  age() {
     return new Date().getFullYear() - new Date(this.born + '').getFullYear();
   }
 };

JavaScript/3-mixin-behavior.js

@@ -5,11 +5,11 @@ function scalable(image) {
 }
 
 function lazy(image) {
-  let scale = image.scale;
+  const scale = image.scale;
   image.scale = () => setImmediate(() => scale());
 }
 
-let image = {};
+const image = {};
 
 console.log('Mixin scalable() adds method: scale');
 scalable(image);

JavaScript/4-mixin-events.js

@@ -1,21 +1,21 @@
 'use strict';
 
-let extend = (obj, mixin) => (
+const extend = (obj, mixin) => (
   Object.keys(mixin).forEach(key => obj[key] = mixin[key]), obj
 );
 
-let obj1 = { name: 'Marcus Aurelius', city: 'Rome', born: 121 };
+const obj1 = { name: 'Marcus Aurelius', city: 'Rome', born: 121 };
 
-let mexinEvents = {
-  toString: function() {
+const mexinEvents = {
+  toString() {
     return this.name + ' was born in ' + this.city + ' in ' + this.born;
   },
-  age: function() {
+  age() {
     return new Date().getFullYear() - new Date(this.born + '').getFullYear();
   }
 };
 
-extend(obj1, mix1);
+extend(obj1, mexinEvents);
 console.log(obj1);
 console.log(obj1.toString());
 console.log('His age is ' + obj1.age() + ' as of today');

JavaScript/5-mixin-prototype.js

@@ -1,12 +1,42 @@
 'use strict';
 
+const accessors = {
+
+  string(proto, name, index) {
+    Object.defineProperty(proto.prototype, name, {
+      get() {
+        return this[index];
+      },
+      set(value) {
+        this[index] = value;
+      }
+    });
+  },
+
+  Date(proto, name, index) {
+    Object.defineProperty(proto.prototype, name, {
+      get() {
+        return new Date(this[index]);
+      },
+      set(value) {
+        this[index] = value instanceof Date ? value.toISOString() : value;
+      }
+    });
+  },
+
+  function(proto, name, index, fieldDef) {
+    Object.defineProperty(proto.prototype, name, { get: fieldDef });
+  }
+
+};
+
 // Assign metadata to array elements
 //   data - array of objects
 //   metadata - data describes PrototypeClass structure
 // Returns: built PrototypeClass
 //
 function assignMetadata(data, metadata) {
-  let proto = buildPrototype(metadata);
+  const proto = buildPrototype(metadata);
   assignPrototype(data, proto);
   return proto;
 }
@@ -24,9 +54,9 @@ function assignPrototype(data, proto) {
 // Build Prototype from Metadata
 //
 function buildPrototype(metadata) {
-  let protoClass = function ProtoClass() {};
+  const protoClass = function ProtoClass() {};
   let index = 0, fieldDef, buildGetter, fieldType;
-  for (let name in metadata) {
+  for (const name in metadata) {
     fieldDef = metadata[name];
     fieldType = typeof(fieldDef);
     if (fieldType !== 'function') fieldType = fieldDef;
@@ -36,40 +66,10 @@ function buildPrototype(metadata) {
   return protoClass;
 }
 
-let accessors = {
-
-  string: function(proto, name, index) {
-    Object.defineProperty(proto.prototype, name, {
-      get: function() {
-        return this[index];
-      },
-      set: function(value) {
-        this[index] = value;
-      }
-    });
-  },
-
-  Date: function(proto, name, index) {
-    Object.defineProperty(proto.prototype, name, {
-      get: function() {
-        return new Date(this[index]);
-      },
-      set: function(value) {
-        this[index] = value instanceof Date ? value.toISOString() : value;
-      }
-    });
-  },
-
-  function: function(proto, name, index, fieldDef) {
-    //console.log({proto, name, index, fieldDef});
-    Object.defineProperty(proto.prototype, name, { get: fieldDef });
-  }
-
-};
 
 // Define Data Source
 //
-let data = [
+const data = [
   ['Marcus Aurelius', 'Rome', '212-04-26'],
   ['Victor Glushkov', 'Rostov on Don', '1923-08-24'],
   ['Ibn Arabi', 'Murcia', '1165-11-16'],
@@ -79,11 +79,11 @@ let data = [
 
 // Define metadata to build prototype dynamically
 //
-let metadata = {
+const metadata = {
   name: 'string',
   city: 'string',
   born: 'Date',
-  age: function() {
+  age() {
     return (
       new Date().getFullYear() -
       new Date(this.born + '').getFullYear()
@@ -93,7 +93,7 @@ let metadata = {
 
 // Define query using regular JavaScript syntax
 //
-let query = person => (
+const query = person => (
   person.name !== '' &&
   person.age > 25 &&
   person.city === 'Rome'
@@ -103,5 +103,5 @@ let query = person => (
 assignMetadata(data, metadata);
 
 // Apply query to dataset
-let res = data.filter(query);
+const res = data.filter(query);
 console.dir(res);