Welcome to an essential lesson in your TypeScript preparation. In this lesson, we will focus on Advanced Array Manipulation Techniques, emphasizing the representation and manipulation of arrays directly, without relying on built-in functions, in a strongly typed environment. This topic is crucial when preparing for technical interviews, as many problems frequently involve performing various operations on arrays. Understanding TypeScript's static type system will enable you to write more predictable and bug-resistant code, especially when dealing with complex data operations.

Consider this TypeScript code to rotate an array by k positions. This operation might seem challenging at first, but by understanding how array indices function and utilizing TypeScript's type annotations, the process becomes more straightforward. In TypeScript, the slice() method allows us to extract parts of an array, and concat() is used for array concatenation. By using these methods together, we achieve the desired rotation. Understanding this technique can help you manipulate arrays efficiently in TypeScript.

Here is how the code looks:

In this example, when k = 3, nums.slice(-3) yields [5, 6, 7], and nums.slice(0, -3) yields . Combining these two parts results in , achieving the desired rotation. TypeScript's type annotations help ensure the correct data types are used, thus preventing runtime errors related to type mismatches.