Rust program to print only keys of a HashMap

Rust | HashMap Example: Write a program to print only keys of a HashMap.
Submitted by Nidhi, on October 14, 2021

Problem Solution:

In this program, we will create a HashMap and then we will insert items into HashMap using the insert() function. After that, we will print only the keys of created HashMap.

Program/Source Code:

The source code to print only keys of a HashMap is given below. The given program is compiled and executed successfully.

// Rust program to print only keys 
// of a HashMap

use std::collections::HashMap;

fn main() 
{
    let mut map = HashMap::new();

    map.insert("Key1", 101);
    map.insert("Key2", 102);
    map.insert("Key3", 103);
    map.insert("Key4", 104);

    println!("HashMap Keys:");
    for key in map.keys() {
        println!("  {}", key);
    }
}

Output:

HashMap Keys:
  Key1
  Key4
  Key2
  Key3

Explanation:

Here we created a HashMap. Then we inserted the item into HashMap and printed the only keys of created HashMap using the keys() method.