35-Tutorial-HashSet-continued-onwards.md

HashSet

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Creating a HashSet in Rust (continued)

Set Operations (continued)

2. Intersection of two Sets

We can use the intersection() method to find the intersection between two sets. For example,

use std::collections::HashSet;

fn main() {
    let hashset1 = HashSet::from([2, 7, 8]);
    let hashset2 = HashSet::from([1, 2, 7]);
    
    // Intersection of hashsets
    let result: HashSet<_> = hashset1.intersection(&hashset2).collect();
    
    println!("hashset1 = {:?}", hashset1);
    println!("hashset2 = {:?}", hashset2);
    println!("intersection = {:?}", result);
}

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Aside

Note:

This code was already added to the main.rs file in programiz/attempt-01

---

Aside:

Note:

code to compile:

(from Rust-Start folder in git bash)

rustc programiz/attempt-01/main.rs

code to run

programiz/attempt-01/main.exe

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Output

hashset1 = {2, 7, 8}
hashset2 = {1, 2, 7}
intersection = {2, 7}

---

Aside

Note

Key point above here seems to be

the line

intersection = {2, 7}

in output,

which seems to be

The intersection HashSet

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3. Difference between two Sets

We can use the difference() method to find the difference between two sets. For example,

use std::collections::HashSet;

fn main() {
    let hashset1 = HashSet::from([1, 2, 3, 4]);
    let hashset2 = HashSet::from([4, 3, 2]);
    
    // Difference between hashsets
    let result: HashSet<_> = hashset1.difference(&hashset2).collect();
    
    println!("hashset1 = {:?}", hashset1);
    println!("hashset2 = {:?}", hashset2);
    println!("difference = {:?}", result);
}

Output

hashset1 = {4, 1, 2, 3}
hashset2 = {4, 3, 2}
difference = {1}

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4. Symmetric Difference between two Sets

We can use the symmetric_difference() method to find the symmetric difference between two sets. The symmetric difference returns values from both sets except the ones in both.

use std::collections::HashSet;

fn main() {
    let hashset1 = HashSet::from([2, 7, 8]);
    let hashset2 = HashSet::from([1, 2, 7, 9]);
    
    // Symmetric difference of hashsets
    let result: HashSet<_> = hashset1.symmetric_difference(&hashset2).collect();
    
    println!("hashset1 = {:?}", hashset1);
    println!("hashset2 = {:?}", hashset2);
    println!("symmetric difference = {:?}", result);
}

Output

hashset1 = {7, 2, 8}
hashset2 = {2, 9, 7, 1}
symmetric difference = {8, 9, 1}

36-Tutorial-Iterators-onwards.md