Rust Arrays & Vectors Tutorial | Fixed vs Dynamic Collections for Beginners

Rust Arrays & Vectors Tutorial | Fixed vs Dynamic Collections for Beginners

Rust offers two primary collection types for storing multiple values: arrays and vectors. Arrays have a fixed size known at compile time, while vectors are dynamic and can grow or shrink during runtime. This tutorial demonstrates how to create, access, and iterate over both arrays and vectors, providing a solid foundation for managing collections in Rust.

Code

fn main() {
  // Arrays: fixed-size collection of integers
  let numbers = [10, 20, 30, 40, 50];
  println!("First element: {}", numbers[0]);      // Access first element (index 0)
  println!("Array length: {}", numbers.len());    // Get array length

  // Vectors: dynamic-size collection of strings
  let mut fruits = Vec::new();                     // Create a new empty vector
  fruits.push("Apple");                            // Add elements
  fruits.push("Banana");
  fruits.push("Cherry");
  println!("Fruits: {:?}", fruits);                // Print entire vector

  // Iterating over an array
  let scores = [85, 92, 78, 95, 88];
  let mut total = 0;
  for score in scores {
    println!("Score: {}", score);                   // Print each score
    total += score;                                 // Sum scores
  }
  let average = total as f64 / scores.len() as f64; // Calculate average
  println!("Total: {}", total);
  println!("Average: {:.2}", average);
}

Key Points

• Arrays have a fixed size determined at compile time and store elements of the same type.
• Vectors are dynamic collections that can grow or shrink using methods like push().
• Both arrays and vectors are zero-indexed, meaning indexing starts at 0.
• Use len() to get the number of elements in arrays and vectors.
• For loops provide a simple way to iterate over elements in both arrays and vectors.