How to Initialize a Set in Rust

How to Initialize a Set in Rust ?

Answer

To initialize a set in Rust, you can use the HashSet struct from the std::collections module.


✐ Examples

1 Initialize Set with Elements

In this example,

  1. We include the necessary module by using use std::collections::HashSet.
  2. We declare a HashSet variable named my_set using the HashSet::new() method.
  3. We can add initial elements to my_set using the insert method.
  4. The HashSet struct in Rust ensures that all elements are unique and provides efficient methods for common set operations.

Rust Program

use std::collections::HashSet;

fn main() {
    // Declare and initialize a set
    let mut my_set: HashSet<&str> = HashSet::new();

    // Add initial elements to the set
    my_set.insert("apple");
    my_set.insert("banana");
    my_set.insert("orange");

    // my_set now contains "apple", "banana", and "orange"

    // Example usage:
    // Add an element to the set
    my_set.insert("kiwi");

    // Remove an element from the set
    my_set.remove("banana");

    // Check if an element is present in the set
    let contains_element = my_set.contains("apple");

    println!("Is element 'apple' present in the set: {}", contains_element);
}

Output

Is element 'apple' present in the set: true

2 Initialize Empty Set

In this example,

  1. We include the necessary module by using use std::collections::HashSet.
  2. We declare an empty HashSet variable named empty_set using the HashSet::new() method.
  3. The HashSet::new() method initializes an empty set that is ready to be used for storing unique elements.
  4. We can now manipulate empty_set using set operations such as adding elements, removing elements, and checking for membership.

Rust Program

use std::collections::HashSet;

fn main() {
    // Declare and initialize an empty set
    let mut empty_set: HashSet<&str> = HashSet::new();

    // empty_set is now initialized as an empty set

    // Example usage:
    // Add elements to the set
    empty_set.insert("apple");

    // Remove elements from the set
    empty_set.remove("apple");

    // Check if an element is present in the set
    let contains_element = empty_set.contains("apple");

    println!("Is element 'apple' present in the set: {}", contains_element);
}

Output

Is element 'apple' present in the set: false

Summary

In this tutorial, we learned How to Initialize a Set in Rust language with well detailed examples.


More Rust Sets Tutorials

  1. How to create an Empty Set in Rust ?
  2. How to Initialize a Set in Rust ?
  3. How to Get Length of a Set in Rust ?
  4. How to create a Set of size N in Rust ?
  5. How to create a Set of Numbers from 1 to N in Rust ?
  6. How to create a Set of integers in Rust ?
  7. How to create a Set of Strings in Rust ?
  8. How to Access Items in a Set in Rust ?
  9. How to get a Random Item in a Set in Rust ?
  10. How to Iterate Over a Set in Rust ?
  11. How to check if a Set is Empty in Rust ?
  12. How to check if a Set is Not Empty in Rust ?
  13. How to get Subset from a Set in Rust ?
  14. How to check if a Specific Item is present in the Set in Rust ?
  15. How to check if a Set contains all the items of Another Set in Rust ?
  16. How to Sort Items of a Set in Rust ?
  17. How to Copy a Set in Rust ?
  18. How to add an Item to a Set in Rust ?
  19. How to find Union of Two Sets in Rust ?
  20. How to find Intersection of Two Sets in Rust ?
  21. How to check if Two Sets are Equal in Rust ?
  22. How to Convert a Set of Integers to a Set of Strings in Rust ?
  23. How to Convert a Set of Strings to a Set of Integers in Rust ?
  24. How to Convert a Set of Floats to a Set of Strings in Rust ?
  25. How to Convert a Set of Strings to a Set of Floats in Rust ?
  26. How to Filter Items of a Set based on a Condition in Rust ?
  27. How to Remove Specific Item from a Set in Rust ?
  28. How to Remove Items from Set based on a Condition in Rust ?
  29. How to create a Set of Sets in Rust ?