做金融的网站有哪些,商标图案参考,郑州软件app开发公司,网站 设计 方案js中__proto__和prototype的区别和关系 1.对象有属性__proto__,指向该对象的构造函数的原型对象。 2.方法除了有属性__proto__,还有属性prototype#xff0c;prototype指向该方法的原型对象。 深入浅出妙用 Javascript 中 apply、call、bind ***两道面试题*** 关于js中伪数… js中__proto__和prototype的区别和关系 1.对象有属性__proto__,指向该对象的构造函数的原型对象。 2.方法除了有属性__proto__,还有属性prototypeprototype指向该方法的原型对象。 深入浅出妙用 Javascript 中 apply、call、bind ***两道面试题*** 关于js中伪数组 我们可以通过Array.prototype.slice.call(fakeArray)将伪数组转变为真正的Array对象。 JS的splice()方法和slice()方法 1.如何利用splice方法实现数组去重 2.es6去重数组 // 去除数组的重复成员
[...new Set(array)]
或者
Array.from(new Set(array)); ES6入门 js日期格式化 function formatDate(date) {var fmtyyyy-MMvar o {M: date.getMonth() 1, //月份 d: date.getDate(), //日 h: date.getHours(), //小时 m: date.getMinutes(), //分 s: date.getSeconds(), //秒 q: Math.floor((date.getMonth() 3) / 3), //季度 S: date.getMilliseconds() //毫秒 };if (/(y)/.test(fmt)) fmt fmt.replace(RegExp.$1, (date.getFullYear() ).substr(4 - RegExp.$1.length));for (var k in o)if (new RegExp(( k )).test(fmt)) fmt fmt.replace(RegExp.$1, (RegExp.$1.length 1) ? (o[k]) : ((00 o[k]).substr(( o[k]).length)));return fmt;} getNowFormatDate(date) {var seperator1 -;var seperator2 :;var month date.getMonth() 1;var strDate date.getDate();if (month 1 month 9) {month 0 month;}if (strDate 0 strDate 9) {strDate 0 strDate;}var currentdate date.getFullYear() seperator1 month seperator1 strDate date.getHours() seperator2 date.getMinutes() seperator2 date.getSeconds();return currentdate;} js Promise 简单测试一下 then函数可以返回新的promise。resolve()函数的返回值会传递到then(resolve, reject)函数中的resolve方法中。 Promise((resolve){resolve((){return xixi;})}).then((fun){console.log(fun()); return Promise((resolve){resolve((){return haha})}).then((fun){console.log(fun())})}); 理解 Promise 简单实现的背后原理 //一个简单的Promise实现方案function Promise(fn) {var value null;var events [];this.then function(f) {events.push(f); return this;}function resolve(newValue) {var f events.shift();f(newValue, resolve);}fn(resolve);
}
function a() { return new Promise(function(resolve) {console.log(get...);setTimeout(function() {console.log(get 1);resolve(1);}, 1000)});
}
a().then(function(value, resolve) {console.log(get...);setTimeout(function() {console.log(get 2);resolve(2);}, 1000)
}).then(function(value, resolve) {console.log(value)
})这样就得到控制台如下的结果
get...
get 1
get...
get 2
2 JavaScript进阶之路——认识和使用Promise重构你的Js代码 。一个较为复杂的Promise实现方案如下。 // see http://promises-aplus.github.io/promises-spec/
// see https://github.com/cujojs/when/blob/master/lib/makePromise.js;(function(root, factory) {if (typeof module ! undefined module.exports) {// CommonJSmodule.exports factory();} else if (typeof define function define.amd) {// AMD / RequireJSdefine(factory);} else {root.Promise factory.call(root);}
}(this, function() {use strict;function Promise(resolver) {if(!(this instanceof Promise)) return new Promise(resolver);this.status pending;this.value;this.reason;// then may be called multiple times on the same promisethis._resolves [];this._rejects [];if(isFn(resolver)) resolver(this.resolve.bind(this), this.reject.bind(this));return this;};Promise.prototype.then function(resolve, reject) {var next this._next || (this._next Promise());var status this.status;var x;if(pending status) {isFn(resolve) this._resolves.push(resolve);isFn(reject) this._rejects.push(reject);return next;}if(resolved status) {if(!isFn(resolve)) {next.resolve(resolve);} else {try {x resolve(this.value);resolveX(next, x);} catch(e) {this.reject(e);}}return next;}if(rejected status) {if(!isFn(reject)) {next.reject(reject);} else {try {x reject(this.reason);resolveX(next, x);} catch(e) {this.reject(e);}}return next;}};Promise.prototype.resolve function(value) {if(rejected this.status) throw Error(Illegal call.);this.status resolved;this.value value;this._resolves.length fireQ(this);return this;};Promise.prototype.reject function(reason) {if(resolved this.status) throw Error(Illegal call.);this.status rejected;this.reason reason;this._rejects.length fireQ(this);return this;};// shortcut of promise.then(undefined, reject)Promise.prototype.catch function(reject) {return this.then(void 0, reject);};// return a promise with another promise passing inPromise.cast function(arg) {var p Promise();if(arg instanceof Promise) return resolvePromise(p, arg);else return Promise.resolve(arg);};// return a promise which resolved with arg// the arg maybe a thanable object or thanable function or otherPromise.resolve function(arg) {var p Promise();if(isThenable(arg)) return resolveThen(p, arg);else return p.resolve(arg);};Promise.all function(promises) {;};// return a promise which reject with reason// reason must be an instance of Error objectPromise.reject function(reason) {if(!(reason instanceof Error)) throw Error(reason must be an instance of Error);var p Promise();p.reject(reason);return p;};function resolveX(promise, x) {if(x promise) promise.reject(new Error(TypeError));if(x instanceof Promise) return resolvePromise(promise, x);else if(isThenable(x)) return resolveThen(promise, x);else return promise.resolve(x);};function resolvePromise(promise, promise2) {var status promise2.status;if(pending status) {promise2.then(promise.resolve.bind(promise), promise.reject.bind(promise));}if(resolved status) promise.resolve(promise2.value);if(rejected status) promise.reject(promise2.reason);return promise;};function resolveThen(promise, thanable) {var called;var resolve once(function(x) {if(called) return;resolveX(promise, x);called true;});var reject once(function(r) {if(called) return;promise.reject(r);called true;});try {thanable.then.call(thanable, resolve, reject);} catch(e) {if(!called) throw e;else promise.reject(e);}return promise;};function fireQ(promise) {var status promise.status;var queue promise[resolved status ? _resolves : _rejects];var arg promise[resolved status ? value : reason];var fn;var x;while(fn queue.shift()) {x fn.call(promise, arg);resolveX(promise._next, x);}return promise;};function noop () {};function isFn(fn) {return function type(fn);};function isObj(o) {return object type(o);};function type(obj) {var o {};return o.toString.call(obj).replace(/\[object (\w)\]/, $1).toLowerCase();};function isThenable(obj) {return obj obj.then isFn(obj.then);};function once(fn) {var called;return function() {if(called) return;fn.apply(this, arguments);called true;};};return Promise;
})); View Code 转载于:https://www.cnblogs.com/hujunzheng/p/6377797.html
