Answer1215

摘要： Take a function as arguement, and the function only return true of false. If the function 'f' return ture, when complement(f) will return false. var i 阅读全文

摘要： In JavaScript, many libraries use string arguments to change behavior. In this lesson we learn how Typescript catches string related errors at compile 阅读全文

摘要： Now is a great way to deploy your node application, but the generated URLs aren't memorable or easily remembered. With Now's alias command, you can fi 阅读全文

摘要： CSS calc() allows you to mix and match units to get real-time calculations. It's useful when you need to size elements but you have some unknown numbe 阅读全文

摘要： When to use Interface and when to use Class. Let's see one example: We have an Interface 'Lesson' and a Class 'Lesson'. At this point, I would love to 阅读全文

摘要： Sometimes we want our function arguments to be able to accept more than 1 type; e.g. a string or an array. This lesson will show us how to assign more 阅读全文

摘要： When an Observer subscribe to a BehaviorSubject. It receivces the last emitted value and then all the subsequent values. BehaviorSubject requires that 阅读全文

摘要： This lesson teaches you how a Subject is simply a hybrid of Observable and Observer which can act as a bridge between the source Observable and multip 阅读全文

摘要： import { Injectable } from '@angular/core'; import {RealtimeService} from "../shared"; import {FirebaseListObservable} from "angularfire2"; @Injectable() export class CourseService { courses$: Fi... 阅读全文

摘要： In this lesson we are going to learn how to use AngularFire 2 to query objects, and read them from the Firebase realtime database. In this lesson we a 阅读全文