Question

How to create HashMap in Rust

Answer 1

use std::collections::HashMap;

fn main() {
   let mut hm = HashMap::new();
   
   hm.insert("R1", "Rust");
   hm.insert("C2", "C++");
   hm.insert("J3", "Java");
   
   println!("{:?}", hm);
}
 
 
 
 
/*
run:
 
{"C2": "C++", "J3": "Java", "R1": "Rust"}
 
*/

 

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Answer 2

use std::collections::HashMap;

fn main() {
   let mut hm: HashMap<String, i32> = HashMap::new();
   
   hm.insert("Rust".to_string(), 12);
   hm.insert("C++".to_string(), 17);
   hm.insert("Java".to_string(), 19);
   
   println!("{:?}", hm);
}


 
 
/*
run:
 
{"C++": 17, "Rust": 12, "Java": 19}
 
*/

 

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Answer 3

use std::collections::HashMap;

fn main() {
    let hm = HashMap::from([
        ("Rust", 3.8),
        ("C++", 2.1),
        ("Java", 8.3),
        ("C", 19.7),
    ]);

    println!("{:?}", hm);
}


 
 
/*
run:
 
{"C": 19.7, "Rust": 3.8, "Java": 8.3, "C++": 2.1}
 
*/

 

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