JS Design Pattern Basics

1. Polymorphism (' Do what ' and ' who to do ' separate)

The same action applies to different objects, which can produce different interpretations and different execution results (for example, different animal sounds). will be separated from the same.

//ObjectvarMakeSound =function(animal) {animal.sound ();}//different OperationsvarDuck =function() {};D uck.prototype.sound=function() {Console.log (' Quack ');}//different behaviors.varChicken =function(){}; Chicken.prototype.sound=function() {Console.log (' Giggle ');} MakeSound (NewDuck ()); MakeSound (NewChicken ());

Use inheritance to get polymorphic effects.  (A sparrow is flying, a magpie is flying) it can be said that a bird is flying. Java uses abstract class inheritance.

Polymorphism and Design Patterns (Command mode, combo mode, policy mode)

2. Encapsulation (more important package changes, separating the unchanging parts from the easily changing ones)

1) package data. 2) package implementation. (iterator, each) 3) package type. 4) package changes.

//Encapsulation Implementationfunction$each (Jn, fn) {varLen =jn.length; if("number" = = =typeofLen) {         for(vari = 0; i < Len; i++) {            Try{fn (jn[i], I,JN); } Catch(e) {if($ Break(e)) { Break; } Else {                    Throwe;            }; }        }    } Else {         for(varKinchJn) {            Try{fn (jn[k], K,JN); } Catch(e) {if($ Break(e)) { Break; } Else {                    Throwe;            }; }        }    }}

3. Cloning.

function (obj) {    varfunction() {};     = obj;     return New F ();}

4. Open-closed principle.

The logic of putting in too much if-else out of the function.

5. Single principle.

JS design mode Basics