This course is the first in a series that will allow you to expand your skills as an Android developer into the world of cross-platform mobile development. This will allow you to use your foundations as an Android developer to build cross-platform mobile applications. The first step in this expansion is learning to program in JavaScript. This will prepare you to learn to use the React library for mobile development. JavaScript is the programming language that powers the modern web. In this course, you will learn the basic concepts of web development with JavaScript. You will work with functions, objects, arrays, variables, data types, the HTML DOM, and much more. You will learn how to use JavaScript and discover interactive possibilities with modern JavaScript technologies. Finally, you will learn about the practice of testing code and how to write a unit test using Jest. This course can be applied to multiple Specializations or Professional Certificates programs. Completing this course will count towards your learning in any of the following programs: • Meta Android Developer Professional Certificate • Meta iOS Developer Professional Certificate By the end of this course you will be able to: • Explain the basic concepts of web development with Javavscript. • Practice using functions, objects, arrays, variables, data types, the HTML DOM, and much more. • Use JavaScript within the React framework • Practice testing code and how to write a unit test using Jest