**Course Title:** Mastering Rust: From Basics to Systems Programming **Section Title:** Data Structures: Arrays, Vectors, and Strings **Topic:** Common operations on collections. ### Introduction to Common Operations on Collections In Rust, collections are groups of items that can be manipulated and transformed in various ways. The most common collections are arrays, vectors, and strings. In this topic, we will cover common operations that can be performed on these collections, such as indexing, slicing, and iterating. ### Indexing Indexing is the process of accessing a specific element in a collection. In Rust, indexing is done using the index operator `[]`. The index of the first element is 0. ```rust fn main() { let numbers = [1, 2, 3, 4, 5]; println!("The second number is: {}", numbers[1]); } ``` ### Slicing Slicing is the process of extracting a subset of elements from a collection. In Rust, slicing is done using the slicing operator `[]` with a range. The range is specified by two indices, the start index and the end index. ```rust fn main() { let numbers = [1, 2, 3, 4, 5]; let slice = &numbers[1..3]; println!("The slice is: {:?}", slice); } ``` ### Iterating Iterating is the process of going through each element in a collection. In Rust, iterating can be done using the `for` loop or the `iter()` method. ```rust fn main() { let numbers = [1, 2, 3, 4, 5]; for number in &numbers { println!("The number is: {}", number); } } ``` ### Common Methods for Collections The following are common methods that can be used on collections: * `iter()`: Returns an iterator over the collection. * `len()`: Returns the length of the collection. * `capacity()`: Returns the capacity of the collection. * `resize()`: Resizes the collection to the specified length. * `push()`: Adds an element to the end of the collection. * `pop()`: Removes an element from the end of the collection. ```rust fn main() { let mut numbers = Vec::new(); numbers.push(1); numbers.push(2); numbers.push(3); println!("The length of the vector is: {}", numbers.len()); println!("The capacity of the vector is: {}", numbers.capacity()); numbers.resize(5, 0); println!("The vector after resizing: {:?}", numbers); } ``` ### Practical Applications Common operations on collections are used extensively in real-world applications. For example, when building a game, you may need to iterate over a list of players to update their scores. When building a web application, you may need to slice a list of users to display only a subset of them. ### Conclusion In this topic, we covered common operations on collections, including indexing, slicing, and iterating. We also covered common methods that can be used on collections. With this knowledge, you can effectively manipulate and transform collections in Rust. For more information on collections in Rust, you can visit the official Rust documentation: [https://doc.rust-lang.org/std/collections/](https://doc.rust-lang.org/std/collections/). If you have any questions or need further clarification on any of the concepts covered in this topic, please leave a comment below. In the next topic, we will cover error handling in Rust and how to use the `Result` type to handle errors in a safe and efficient way.