How to Remove Items from Set based on a Condition in Rust - Step by Step Examples

How to Remove Items from Set based on a Condition in Rust ?

Answer

To remove items from a set based on a condition in Rust, you can use the retain method, which allows you to keep only the elements that satisfy a given predicate.

✐ Examples

1 Removing Even Numbers from Integer Set

In this example,

We include the necessary crate for sets: use std::collections::HashSet;.
We create a HashSet<i32> named number_set and initialize it with the values [1, 2, 3, 4, 5].iter().cloned().collect().
We use the retain method with a lambda function to define the condition for removing elements. The lambda function |&x| x % 2 != 0 keeps only the odd numbers in the set.
Finally, we iterate over the set and print the remaining elements to the console.

Rust Program

use std::collections::HashSet;

fn main() {
    let mut number_set: HashSet&lt;i32&gt; = [1, 2, 3, 4, 5].iter().cloned().collect();
    number_set.retain(|&x| x % 2 != 0);
    for num in &number_set {
        print!("{} ", num);
    }
    println!();
}

Output

1 3 5

2 Removing Short Strings from String Set

In this example,

We include the necessary crate for sets: use std::collections::HashSet;.
We create a HashSet<String> named string_set and initialize it with the values ["apple", "banana", "cherry", "date", "grape"].iter().cloned().map(String::from).collect().
We use the retain method with a lambda function to define the condition for removing elements. The lambda function |s| s.len() >= 6 keeps only the strings with a length of 6 or more characters.
Finally, we iterate over the set and print the remaining elements to the console.

Rust Program

use std::collections::HashSet;

fn main() {
    let mut string_set: HashSet&lt;String&gt; = ["apple", "banana", "cherry", "date", "grape"].iter().cloned().map(String::from).collect();
    string_set.retain(|s| s.len() &gt;= 6);
    for str in &string_set {
        print!("{} ", str);
    }
    println!();
}

Output

banana cherry

Summary

In this tutorial, we learned How to Remove Items from Set based on a Condition in Rust language with well detailed examples.

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How to Remove Items from Set based on a Condition in Rust - Step by Step Examples

How to Remove Items from Set based on a Condition in Rust ?

Answer

✐ Examples

1 Removing Even Numbers from Integer Set

Rust Program

Output

2 Removing Short Strings from String Set

Rust Program

Output

Summary

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