skywalkerdavid / tipcalculator

Pre-work - Tip Calculator

Tips is a tip calculator application for iOS.

Submitted by: Dawei Wang

Time spent: 4 hours spent in total

User Stories

The following required functionality is complete:

• User can enter a bill amount, choose a tip percentage, and see the tip and total values.
• Settings page to change the default tip percentage.

The following optional features are implemented:

• UI animations
• Remembering the bill amount across app restarts (if <10mins)
• Using locale-specific currency and currency thousands separators.
• Making sure the keyboard is always visible and the bill amount is always the first responder. This way the user doesn't have to tap anywhere to use this app. Just launch the app and start typing.

The following additional features are implemented:

• List anything else that you can get done to improve the app functionality!

Video Walkthrough

Here's a walkthrough of implemented user stories:

GIF created with LiceCap.

Project Analysis

As part of your pre-work submission, please reflect on the app and answer the following questions below:

Question 1: "What are your reactions to the iOS app development platform so far? How would you describe outlets and actions to another developer? Bonus: any idea how they are being implemented under the hood? (It might give you some ideas if you right-click on the Storyboard and click Open As->Source Code")

Answer: [I don't need to write a lot of code to show some UI features. And the logic and UI views are separated pretty well. Outlets of the views are the handler we can use to control the behavior of the views or get the information from the views. And the actions are the callbacks of these views when there are some actions happen.].

Question 2: "Swift uses Automatic Reference Counting (ARC), which is not a garbage collector, to manage memory. Can you explain how you can get a strong reference cycle for closures? (There's a section explaining this concept in the link, how would you summarize as simply as possible?)"

Answer: [This strong reference cycle occurs because closures, like classes, are reference types. When you assign a closure to a property, you are assigning a reference to that closure. In essence, it’s the same problem as above—two strong references are keeping each other alive. However, rather than two class instances, this time it’s a class instance and a closure that are keeping each other alive].

License

Copyright [yyyy] [name of copyright owner]

Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at

    http://www.apache.org/licenses/LICENSE-2.0

Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.

tipcalculator's Issues

Project Feedback!

Looks good, this exercise is intended in part to give you an introduction to the general rhythm of this course. The course is entirely project-based with an app being assigned each week and then due the following week. Each project builds on the last to help each engineer learn the practical elements of iOS development and best practices as quickly as possible. We also do a code review for each submitted project once the program begins.

Great to see you were able to complete some optional features to your app already. The optional tasks available on each project are often the most valuable learnings since they dive deeper into common real-world iOS use cases. We encourage you to continue working on extensions to your tip calculator as a way to further explore iOS development.

See if you can expand the functionality of the app or instead work to improve the user interface by experimenting with colors, spacing, styling, icons, etc. You can update your submission at any time here, and it will notify us to review again.

We'll be following up with you again shortly to outline the next steps in the admissions process.