public/subjects/simple_hash

simple_hash

Instructions

Create a function contain that checks a HashMap to see if it contains a given key.

Create a function remove that removes a given key from the HashMap.

• Note: pay attention to the comment in the usage

Notions

• https://doc.rust-lang.org/rust-by-example/std/hash.html

Expected functions

pub fn contain(h: &HashMap<&str, i32>, s: &str) -> bool {}

pub fn remove(h: &mut HashMap<&str, i32>, s: &str) {}

Usage

Here is a program to test your function.

use simple_hash::*;
use std::collections::HashMap;

fn main() {
    let mut hash: HashMap<&str, i32> = HashMap::new();
    hash.insert("Daniel", 122);
    hash.insert("Ashley", 333);
    hash.insert("Katie", 334);
    hash.insert("Robert", 14);

    println!(
        "Does the HashMap contains the name Roman? => {}",
        contain(hash.clone(), "Roman")
        //----------^^^^^^^^
        // this is not correct, fix it to match the solution the expected function
    );
    println!(
        "Does the HashMap contains the name Katie? => {}",
        contain(hash.clone(), "Katie")
        //----------^^^^^^^^
        // this is not correct, fix it to match the solution the expected function
    );
    println!("Removing Robert {:?}", remove(hash.clone(), "Robert"));
    println!(
        "Does the HashMap contains the name Robert? => {}",
        contain(hash.clone(), "Robert")
        //----------^^^^^^^^
        // this is not correct, fix it to match the solution the expected function
    );
    println!("Hash {:?}", &hash);
}

And its output

student@ubuntu:~/simple_hash/test$ cargo run
Does the HashMap contains the name Roman? => false
Does the HashMap contains the name Katie? => true
Removing Robert ()
Does the HashMap contains the name Robert? => false
Hash {"Katie": 334, "Daniel": 122, "Ashley": 333}
student@ubuntu:~/simple_hash/test$