Closures provide a powerful, flexible way for iOS developers to define and use functions in Swift, replacing the blocks used in its predecessor Objective-C. They provide self-contained modules of functionality that you can move around in your code, similar to the lambdas found in other programming languages. Crucially, closures can capture and store references to any constants and variables from the context in which they’re defined.

GraphQL is a query language and runtime for APIs, developed by Facebook in 2012 and later open-sourced in 2015. And it has changed the way we fetch data from our server. Typically, most front-end clients – like React, Angular, Vue, or mobile apps like iOS and Android – use REST APIs to fetch data from the server. REST APIs require more HTTP calls than GraphQL, which leads to over and underfetching.

We use them to manage users’ log-in sessions, impose time-outs, display dates when content was posted and show the most recent publications to users. This is crucial to a variety of apps, from digital diaries to diet and exercise planners, and onto travel-booking resources. As our user bases become more geographically diverse, so time management gets even more important.

Kotlin has gradually replaced Java as the lingua franca of Android programming. It’s a more concise language than Java, meaning your code works harder and you can build leaner applications. And Kotlin Collections are fundamental. These collections play a fundamental role in our work as programmers by simplifying the organization and management of data. Whether it’s a list, set, map or other data structure, they allow us to categorize and store data logically.

In the 21st century, practically all technological innovation on the planet has been channeled into the mobile phone. The first generation of mobile phones simply allowed you to make calls, store numbers and play rudimentary games (some of which, like Snake, didn’t even have an end sequence because the designers didn’t think anyone would complete them). Today mobile phones are computers in our pocket, allowing us to shop, date, stream videos, buy food, order cabs and find our way around.

The software industry has evolved more quickly in 10 years than most industries do in 1,000, yet we continue to grapple with the basic elements of date and time. Practically all our apps rely on time in some way, and when our users are spread all over the world it can be fiendishly difficult to get the timestamps right. Kotlin language, the dominant Android programming language, provides native classes (or blueprints) to help us deal with date and time.

Android has surged past iOS to dominate the world’s smartphone market, but its ecosystem is growing at an exponential rate. There were more than 24,000 different Android devices at the last count, which places major strains on devs. To learn Android development, you have to learn how to optimize for hundreds of different devices. So you need a clear learning plan that can be applied to the entire Android ecosystem.

There are now nearly 9 million apps worldwide, and practically all of them run on an internal clock. Financial apps are built on timestamped data. Office apps run on calendars. Social apps are defined by their feeds, timelines and anniversaries. So, as devs, we need to know how to compute date and time. JavaScript, the world’s most popular programming language, has plenty of helpful APIs, but they can throw up complications if you’ve never used them before.

Developers striving to learn iOS face a rate of change that’s unprecedented in mobile history. iOS 17 is about to go live, just weeks after Apple released the latest versions of iOS 15 and 16. The latest upgrade will cut off all versions up to the iPhone X (which itself is only six years old) and comes with: If you really want to learn and master iOS app development, you need a blend of learning resources that cover all these topics, as well as all the basics of iOS.

Application Programming Interface, or API, development is a critical aspect of modern software engineering, enabling diverse software systems to interact and share data seamlessly. The API serves as a contract between different software applications, outlining how they can communicate with one another. Two of the most popular architectural styles for building Web APIs are Representational State Transfer (REST) and GraphQL.