Introduction to the ArkTS language(1)

ArkTS: A High - Performance Programming Language for Application Development

Introduction to ArkTS

ArkTS is a programming language designed for building high - performance applications. It optimizes the TypeScript syntax to deliver higher performance and development efficiency.

As mobile devices become increasingly prevalent in daily life, many programming languages, initially designed without mobile devices in mind, have led to slow, inefficient applications with high power consumption. The need for programming language optimization for mobile environments is growing. ArkTS is designed to address these issues, focusing on improving runtime efficiency.

TypeScript, a popular language, extends JavaScript with type definitions. ArkTS further extends TypeScript. Loved by developers for its structured JavaScript coding approach, TypeScript serves as the foundation for ArkTS, which aims to maintain most of TypeScript's syntax. This allows existing TypeScript developers to transition seamlessly and enables mobile developers to quickly get started with ArkTS.

Key Features of ArkTS

• Low Runtime Overhead: ArkTS imposes stricter limitations on TypeScript's dynamic typing to reduce runtime overhead and enhance execution efficiency. By removing dynamic typing, ArkTS code can be more effectively compiled and optimized before runtime, enabling faster app launches and lower power consumption.
• Interoperability with JavaScript: Recognizing that many mobile app developers want to reuse their TypeScript and JavaScript code and libraries, ArkTS provides seamless interoperability with JavaScript. This allows developers to easily integrate JavaScript code into their applications and leverage existing code and libraries for ArkTS development.

Support for ArkUI

To ensure the best application development experience, ArkTS supports the declarative syntax of the ArkUI framework and other features. Since these features go beyond the scope of existing TypeScript, detailed ArkUI examples are provided in the "Support for ArkUI" chapter.

About This Tutorial

This tutorial aims to guide developers in understanding ArkTS's core features, syntax, and best practices, enabling them to efficiently build high - performance mobile applications with ArkTS.

For a more in - depth understanding of the ArkTS language, refer to the specific ArkTS guide and DevEco Studio.

Basic Knowledge

Declarations

ArkTS uses declarations to introduce variables, constants, functions, and types.

Variable Declaration

Declarations starting with the keyword let introduce variables that can take on different values during program execution:

let hi: string = 'hello';
hi = 'hello, world';

Constant Declaration

Declarations starting with the keyword const introduce read - only constants that can only be assigned once:

const hello: string = 'hello';

Reassigning a constant will result in a compile - time error.

Type Inference

As a statically - typed language, ArkTS requires all data types to be determined at compile time. However, if a variable or constant declaration includes an initial value, developers don't need to explicitly specify its type. The ArkTS specification outlines all scenarios where types can be automatically inferred.

In the following example, both declaration statements are valid, and both variables are of the string type:

let hi1: string = 'hello';
let hi2 = 'hello, world';