Analysis of JavaScript code reuse pattern examples_javascript skills

function inherit(C, P) { C.prototype = new P();}
// Parent constructor function Parent(name) { this.name = name || 'Adam';}
// Add say function to the prototype Parent.prototype .say = function () { return this.name;};
// Child constructor is empty function Child(name) {}
// Execute inheritance inherit(Child, Parent); var kid = new Child ();console.log(kid.say());
// "Adam"var kiddo = new Child();kiddo.name = "Patrick";console.log(kiddo.say());
// "Patrick"// Disadvantage: parameters cannot be passed into the Child constructor var s = new Child('Seth'); console.log(s.say());
// "Adam" The disadvantage of this mode is that Child cannot pass in parameters, so it is basically useless.

// Parent constructor function Parent(name) { this.name = name || 'Adam';}
// Add the say function to the prototype Parent.prototype.say = function () { return this.name;};
// Child constructor function Child( name) { Parent.apply(this, arguments);}var kid = new Child("Patrick");console.log(kid.name);
// "Patrick"// Disadvantages: No constructor Inherit the say method console.log(typeof kid.say);
// The disadvantage of "undefined" is also obvious. The say method is not available because it is not inherited.

function inherit(C, P) { C.prototype = P.prototype;}
// parent constructor function Parent (name) { this.name = name || 'Adam';}
// Add the say function to the prototype Parent.prototype.say = function () { return this.name;};
// Child construction Function function Child(name) {}inherit(Child, Parent);var kid = new Child('Patrick');console.log(kid.name);
// undefinedconsole.log(typeof kid.say);
// functionkid.name = 'Patrick'; console.log(kid.say());
// Patrickconsole.dir(kid); It's definitely the same, the parameters of Child were not received correctly.

/* Closure*/var inherit = (function () { var F = function () { }; return function (C, P) { F.prototype = P.prototype; C.prototype = new F(); C.uber = P.prototype; CC.prototype.constructor = C; }} ());function Parent(name) { this.name = name || 'Adam';}// Add say to the prototype Function Parent.prototype.say = function () { return this.name;};// Child constructor function Child(name) {}inherit(Child, Parent);var kid = new Child();console.log(kid .name); // undefinedconsole.log(typeof kid.say); // functionkid.name = 'Patrick';console.log(kid.say()); // Patrickvar kid2 = new Child("Tom"); console.log(kid.say()); console.log(kid.constructor.name); // Childconsole.log(kid.constructor === Parent); // false The problem remains the same, Child cannot receive parameters normally.

Mode 6: klass
For this mode, let’s start with the code:
var klass = function (Parent, props) { var Child, F, i; //
1. // New constructor Child = function () { if (Child.uber && Child.uber.hasOwnProperty("__construct")) { Child.uber.__construct.apply(this, arguments); } if (Child .prototype.hasOwnProperty("__construct")) { Child.prototype.__construct.apply(this, arguments); } }; //
2. // Inherit ParentParent = Parent || Object; F = function () { }; F.prototype = Parent.prototype; Child.prototype = new F(); Child.uber = Parent.prototype; ChildChild.prototype.constructor = Child; /
3. // Add implementation method for (i in props) { if (props.hasOwnProperty(i)) { Child.prototype[i] = props[i]; } }
// return the "class" return Child;};var Man = klass(null, { __construct: function (what) { console.log("Man's constructor"); this.name = what; }, getName: function () { return this.name; }});var first = new Man('Adam') ;
// logs "Man's constructor" first.getName();
// "Adam" var SuperMan = klass(Man, { __construct: function (what) { console.log("SuperMan's constructor"); }, getName: function () { var name = SuperMan.uber.getName.call(this); return "I am " name; }});var clark = new SuperMan('Clark Kent');clark.getName() ;
// "I am Clark Kent"console.log(clark instanceof Man);
// trueconsole.log(clark instanceof SuperMan);