How to Initialize a Set in Rust - Step by Step Examples

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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,

We include the necessary module by using use std::collections::HashSet.
We declare a HashSet variable named my_set using the HashSet::new() method.
We can add initial elements to my_set using the insert method.
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,

We include the necessary module by using use std::collections::HashSet.
We declare an empty HashSet variable named empty_set using the HashSet::new() method.
The HashSet::new() method initializes an empty set that is ready to be used for storing unique elements.
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.

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How to Initialize a Set in Rust - Step by Step Examples

How to Initialize a Set in Rust ?

Answer

✐ Examples

1 Initialize Set with Elements

Rust Program

Output

2 Initialize Empty Set

Rust Program

Output

Summary

More Rust Sets Tutorials